HomeMy WebLinkAboutCWMP Final Update Volume I Oct 2014 for Web_201410290717372802CWMPUpdate
Volume I of II
#225139.00
Town of Nantucket
October 2014woodardcurran.com
COMMITMENT &INTEGRITY DRIVE RESULTS
Town of Nantucket (#225139.00)i Woodard & Curran
Final CWMP Update Report Volume I October 2014
TABLE OF CONTENTS
SECTION PAGE NO.
EXECUTIVE SUMMARY.........................................................................................................................................ES-1
1.CWMP UPDATE..............................................................................................................................................1-1
1.1 Summary of 2004 CWMP/EIR...............................................................................................................1-1
Phase I CMWP/EIR....................................................................................................................1-11.1.1
Phase II CWMP/Draft EIR...........................................................................................................1-41.1.2
Phase III CWMP/Final EIR..........................................................................................................1-61.1.3
Summary of Massachusetts Estuaries Program.........................................................................1-61.1.4
Overall 2004 CWMP/EIR Summary............................................................................................1-71.1.5
2.DATA COLLECTION AND REVIEW...............................................................................................................2-1
2.1 Update to Needs Areas.........................................................................................................................2-1
2.2 Zoning....................................................................................................................................................2-2
2.3 Board of Health File Review..................................................................................................................2-2
2.4 Massachusetts Estuaries Program (MEP).............................................................................................2-5
Nantucket Harbor and Polpis Harbor MEP.................................................................................2-72.4.1
Model Run Scenarios..................................................................................................................2-72.4.2
CWMP Update Adaptive Management Plan to Meet Nantucket Harbor/Polpis Harbor TMDL..2-132.4.3
2.4.3.1 Sesachacha Pond MEP.................................................................................................2-15
Model Run Scenario.................................................................................................................2-152.4.4
2.4.4.1 Madaket Harbor and Long Pond MEP...........................................................................2-21
2.4.4.2 Hummock Pond MEP.....................................................................................................2-26
2.4.4.2.1 Head of Hummock.............................................................................................. 2-26
2.4.4.2.2 Main Hummock Pond......................................................................................... 2-27
2.5 Total Maximum Daily Loads and Water Quality Impairments..............................................................2-32
Final Nantucket Harbor Embayment System TMDL for Total Nitrogen.....................................2-332.5.1
Draft Madaket and Long Pond Estuarine System TMDL for Total Nitrogen..............................2-352.5.2
2.5.2.1 Model Run Scenario.......................................................................................................2-35
Sesachacha Pond.....................................................................................................................2-372.5.3
Hummock Pond........................................................................................................................2-372.5.4
2.6 Stormwater Update..............................................................................................................................2-37
Evaluation.................................................................................................................................2-382.6.1
2.6.1.1 Street Sweeping.............................................................................................................2-38
2.6.1.2 Catch Basin Cleaning.....................................................................................................2-39
2.6.1.3 Structural Controls.........................................................................................................2-39
2.6.1.4 Opinions of Probable Cost.............................................................................................2-40
Recommendations....................................................................................................................2-412.6.2
2.7 Fertilizer Update..................................................................................................................................2-42
2.8 Landfill Mining......................................................................................................................................2-44
2.9 Potable Water System Expansion Update...........................................................................................2-45
2.10 Nantucket Sewer Act of 2008..............................................................................................................2-48
2.11 Sewer Connection Policy.....................................................................................................................2-48
2.12 Septage Management Plan.................................................................................................................2-50
Regulations...............................................................................................................................2-512.12.1
Inspections................................................................................................................................2-522.12.2
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Final CWMP Update Report Volume I October 2014
Staffing and Funding.................................................................................................................2-522.12.3
Record Keeping........................................................................................................................2-532.12.4
Education and Outreach...........................................................................................................2-532.12.5
Management of Onsite Sewage Disposal Systems..................................................................2-542.12.6
Summary ..................................................................................................................................2-542.12.7
2.13 Board of Health Administrative Consent Order....................................................................................2-55
2.14 Updated Needs Areas and Revised Wastewater Flows and Loads....................................................2-55
Needs and Study Areas Update ...............................................................................................2-572.14.1
2.14.1.1 Madaket and Warrens Landing Needs Areas ................................................................2-57
2.14.1.2 Warrens Landing Needs Area........................................................................................2-59
2.14.1.3 Somerset Needs Area....................................................................................................2-60
2.14.1.4 Monomoy Needs Area ...................................................................................................2-61
2.14.1.5 Shimmo Needs Area......................................................................................................2-61
2.14.1.6 Hummock Pond North Study Area.................................................................................2-62
2.14.1.7 Hummock Pond South Needs Area...............................................................................2-63
2.14.1.8 Miacomet Needs Area....................................................................................................2-64
2.14.1.9 PLUS Needs Area..........................................................................................................2-65
Sewering Priorities....................................................................................................................2-652.14.2
2.14.2.1 Polpis 2-67
2.14.2.2 Pocomo..........................................................................................................................2-67
2.14.2.3 Wauwinet.......................................................................................................................2-67
2.14.2.4 Quidnet...........................................................................................................................2-68
Wastewater Flow and Loads Update........................................................................................2-712.14.3
3.ALTERNATIVES DISCUSSION.......................................................................................................................3-1
3.1 Summary and Update of 2004 CWMP Alternatives...............................................................................3-1
3.2 Re-Evaluation of WWTF Options – Elimination of Proposed Madaket WWTF......................................3-2
3.3 Surfside Wastewater Treatment Facility Recommended Improvements...............................................3-3
3.4 Improvements for Future Capacity........................................................................................................3-4
Additional Aeration Blowers........................................................................................................3-43.4.1
Modifications to the Nitrate Recycle............................................................................................3-43.4.2
3.5 Improvements for Reliability..................................................................................................................3-5
Corrosion Control........................................................................................................................3-53.5.1
Influent Screening.......................................................................................................................3-53.5.2
Vactor Truck Unloading..............................................................................................................3-63.5.3
Aeration Tank Instrumentation....................................................................................................3-63.5.4
Primary Sludge Pump Replacement...........................................................................................3-63.5.5
Membrane Removal Equipment .................................................................................................3-63.5.6
Membrane Inspection and Replacement....................................................................................3-73.5.7
Supervisory Control and Data Acquisition (SCADA) System......................................................3-73.5.8
3.6 Improvements for Energy Efficiency......................................................................................................3-8
3.7 Estimated Conceptual Cost for Improvements......................................................................................3-8
3.8 Re-Evaluation of Loading at Surfside Discharge Beds........................................................................3-10
Background...............................................................................................................................3-103.8.1
Current Site Conditions.............................................................................................................3-113.8.2
3.9 Data Utilizied in Hydrogeological Evaluation.......................................................................................3-14
Calculations of Typical Fall Water Table...................................................................................3-153.9.1
Water Table..............................................................................................................................3-153.9.2
3.10 Summary of Hydrogeological Analysis................................................................................................3-18
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3.11 Shoreline Stability Analysis and Breakout Determination....................................................................3-22
Shoreline...................................................................................................................................3-223.11.1
3.12 Conclusions of Evaluation...................................................................................................................3-23
Additional Bed Loading.............................................................................................................3-233.12.1
Shoreline Stability.....................................................................................................................3-233.12.2
Breakout Potential.....................................................................................................................3-233.12.3
Particle Trace Analysis.............................................................................................................3-233.12.4
3.13 Updated Recommended Plan..............................................................................................................3-27
CWMP Update Final Recommended Plan................................................................................3-273.13.1
Needs Areas in Surfside Wastewater Collection System..........................................................3-273.13.2
3.13.2.1 Madaket.........................................................................................................................3-27
3.13.2.1.1 Environmental Impact......................................................................................... 3-28
3.13.2.2 Warren’s Landing...........................................................................................................3-28
3.13.2.2.1 Environmental Impact......................................................................................... 3-28
3.13.2.3 Somerset........................................................................................................................3-36
3.13.2.3.1 Environmental Impact......................................................................................... 3-36
3.13.2.4 Hummock North.............................................................................................................3-36
3.13.2.4.1 Environmental Impact......................................................................................... 3-37
3.13.2.5 Hummock South.............................................................................................................3-40
3.13.2.5.1 Environmental Impact......................................................................................... 3-40
3.13.2.6 Miacomet........................................................................................................................3-40
3.13.2.6.1 Environmental Impact......................................................................................... 3-41
3.13.2.7 Monomoy.......................................................................................................................3-41
3.13.2.7.1 Environmental Impact......................................................................................... 3-41
3.13.2.8 Shimmo..........................................................................................................................3-42
3.13.2.8.1 Environmental Impact......................................................................................... 3-42
3.13.2.9 Town Sewer District.......................................................................................................3-47
3.13.2.9.1 Environmental Impact......................................................................................... 3-47
3.13.2.10 Town WPZ.....................................................................................................................3-47
3.13.2.10.1 Environmental Impact......................................................................................... 3-47
3.13.2.11 PLUS 3-48
3.13.2.11.1 Environmental Impact......................................................................................... 3-48
Study Areas Recommended for Septage Management Plan Including Areas Managed with3.13.3
Innovative / Alternative Systems...............................................................................................3-48
3.13.3.1 Polpis 3-48
3.13.3.2 Pocomo..........................................................................................................................3-49
3.13.3.3 Wauwinet.......................................................................................................................3-49
3.13.3.4 Surfside..........................................................................................................................3-49
3.13.3.5 Tom Nevers – Low Density............................................................................................3-49
3.13.3.6 Tom Nevers-High Density..............................................................................................3-50
3.13.3.7 Quidnet...........................................................................................................................3-50
3.13.3.8 Siasconset......................................................................................................................3-50
3.13.3.9 Remaining Island...........................................................................................................3-50
Ocean Outfall Alternative..........................................................................................................3-553.13.4
3.14 Environmental Review.........................................................................................................................3-59
Environmental Impacts.............................................................................................................3-593.14.1
3.14.1.1 Direct Impacts................................................................................................................3-60
3.14.1.1.1 Historical, Archaeological, Cultural, Conservation and Recreation..................... 3-60
3.14.1.1.2 Wetlands, Flood Plains, and Agricultural Lands................................................. 3-61
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Final CWMP Update Report Volume I October 2014
3.14.1.1.3 Zones of Contribution of Existing and Proposed Water Supply Sources............ 3-62
3.14.1.1.4 Surface and Groundwater Resources................................................................ 3-62
3.14.1.1.5 Displacements of Households, Businesses, and Services................................. 3-63
3.14.1.1.6 Noise Pollution, Air Pollution, Odor and Public Health Issues Associated with
Construction and Operation................................................................................ 3-63
3.14.1.1.7 Violation of Federal, State, or Local Environmental and Land Use Statutes or
Regulations and Plans Imposed by Such Statues and Regulations................... 3-63
3.14.1.2 Indirect Impacts..............................................................................................................3-63
3.14.1.2.1 Changes in Development and Land Use Patterns.............................................. 3-63
3.14.1.2.2 Pollution Stemming from Changes in Land Use................................................. 3-64
3.14.1.2.3 Damage to Sensitive Ecosystems...................................................................... 3-64
3.14.1.2.4 Socioeconomic Pressures for Expansion........................................................... 3-65
3.15 Summary of Environmental Impact......................................................................................................3-66
3.16 Flow and Waste Reducation – Municipal Water Update......................................................................3-66
Summary ..................................................................................................................................3-673.16.1
3.17 I/I Update.............................................................................................................................................3-68
3.18 GRreenhouse Gas...............................................................................................................................3-68
Sustainable Design Standards..................................................................................................3-693.18.1
SCADA System.........................................................................................................................3-703.18.2
4.PHASE IV REPORT – FINAL RECOMMENDED PLAN..................................................................................4-1
4.1 Needs and Study Areas Final Recommended Plan...............................................................................4-1
Somerset Needs Area – Priority Number One............................................................................4-14.1.1
4.1.1.1 Final Recommended Plan................................................................................................4-2
Madaket and Warrens Landing Needs Areas.............................................................................4-24.1.2
4.1.2.1 Final Recommended Plan................................................................................................4-3
Warrens Landing Needs Area.....................................................................................................4-44.1.3
4.1.3.1 Final Recommended Plan................................................................................................4-5
Monomoy Needs Area................................................................................................................4-54.1.4
4.1.4.1 Final Recommended Plan................................................................................................4-6
Shimmo Needs Area...................................................................................................................4-64.1.5
4.1.5.1 Final Recommended Plan................................................................................................4-7
Hummock Pond North Study Area..............................................................................................4-74.1.6
4.1.6.1 Final Recommended Plan................................................................................................4-8
Hummock Pond South Needs Area............................................................................................4-84.1.7
4.1.7.1 Final Recommended Plan................................................................................................4-9
Miacomet Needs Area................................................................................................................4-94.1.8
4.1.8.1 Final Recommended Plan..............................................................................................4-10
PLUS Needs Area and Town Sewer District In-Fill...................................................................4-104.1.9
4.1.9.1 Sewering Priorities.........................................................................................................4-11
4.1.9.2 Adaptive Management Plan to meet MEP and TMDLs..................................................4-12
4.1.9.3 Sesachacha Pond..........................................................................................................4-13
4.1.9.4 Madaket Harbor/Long Pond...........................................................................................4-13
4.1.9.5 Nantucket Harbor/Polpis Harbor....................................................................................4-14
4.1.9.6 Hummock Pond..............................................................................................................4-14
4.2 Surfside wastewater Treatment FAcility Recommended Improvements..............................................4-14
4.3 Improvements for Future Capacity......................................................................................................4-14
Additional Aeration Blowers......................................................................................................4-154.3.1
Modifications to the Nitrate Recycle..........................................................................................4-154.3.2
Town of Nantucket (#225139.00)v Woodard & Curran
Final CWMP Update Report Volume I October 2014
4.4 Improvements for Reliability................................................................................................................4-15
Corrosion Control......................................................................................................................4-164.4.1
Influent Screening.....................................................................................................................4-164.4.2
Vactor Truck Unloading............................................................................................................4-174.4.3
Aeration Tank Instrumentation..................................................................................................4-174.4.4
Primary Sludge Pump Replacement.........................................................................................4-174.4.5
Membrane Removal Equipment ...............................................................................................4-174.4.6
Membrane Inspection and Replacement..................................................................................4-174.4.7
Supervisory Control and Data Acquisition (SCADA) System....................................................4-184.4.8
4.5 Improvements for Energy Efficiency....................................................................................................4-18
4.6 Estimated Conceptual Cost for Improvements....................................................................................4-19
Modified Groundwater Discharge Permit - Additional Bed Loading..........................................4-214.6.1
4.6.1.1 Downstream Evaluation.................................................................................................4-21
4.6.1.2 Pump Station Evaluation................................................................................................4-22
4.6.1.3 Stormwater Recommendations......................................................................................4-22
4.6.1.4 I/I Recommendations.....................................................................................................4-23
4.7 Awareness of and Adaptation to Climate Change – Planning for the Future.......................................4-26
5.FUNDING AND FINANCING...........................................................................................................................5-1
5.1 Funding and Financing Options.............................................................................................................5-1
State Revolving Fund Loan Program..........................................................................................5-15.1.1
Additional Funding Opportunities................................................................................................5-15.1.2
5.2 Household Costs...................................................................................................................................5-2
Individual Household Cost Scenarios.........................................................................................5-25.2.1
Capital Costs...............................................................................................................................5-35.2.2
Individual Grinder Pumps............................................................................................................5-35.2.3
Operation and Maintenance Costs .............................................................................................5-35.2.4
5.2.4.1 Connection Fees..............................................................................................................5-3
5.2.4.2 Individual Sewer Connections (Private Property).............................................................5-3
5.2.4.3 Plumbing / Electrical Upgrades........................................................................................5-3
5.2.4.4 Septic System Abandonment...........................................................................................5-4
6.PUBLIC OUTREACH.......................................................................................................................................6-1
6.1 General..................................................................................................................................................6-1
6.2 Public Meetings, Outreach and Educational Sessions..........................................................................6-2
6.3 Depositories...........................................................................................................................................6-3
FIGURES
Figure 1-1: 2004 CWMP Areas of Wastewater Need
Figure 1-2: Figure 2-12 from 2004 CWMP
Figure 2-1: BOH Review
Figure 2-2: MEP I-1
Figure 2-3: Figure III-1 from MEP
Figure 2-4: Figure IV-4 from MEP
Figure 2-5: Sentinel Stations in Nantucket and Polpis Harbors
Figure 2-6: Sesachacha Pond Estuary Map
Figure 2-7: Figure III-1 from MEP
Figure 2-8: Figure IV-4 from MEP
Town of Nantucket (#225139.00)vi Woodard & Curran
Final CWMP Update Report Volume I October 2014
Figure 2-9: Figure VI-1 MEP / Sampling Locations
Figure 2-10: 1-2 from MEP
Figure 2-11: Madaket Sub-Watersheds from MEP
Figure 2-12: Figure IV-6 from MEP
Figure 2-13: Sampling Locations
Figure 2-14: Map of HP MEP
Figure 2-15: Hummock Pond Watershed
Figure 2-16: HP Sampling Stations
Figure 2-17: HP Nitrogen contributions
Figure 2-18: Details the Existing Town Water System
Figure 2-19: Updated Needs and Study Areas Map
Figure 2-20: Insert Poster
Figure 3-1: Google Earth Map
Figure 3-2: Water Contours
Figure 3-3: No Load Scenario
Figure 3-4: Typical Summer Flow (August)
Figure 3-5: Typical Winter (February)
Figure 3-6: Shoreline
Figure 3-7: ACOE Shoreline Stability
Figure 3-8: FEMA
Figure 3-9: Overview of Proposed Sewer Collection System
Figure 3-10: Environmental constraints – NHESP
Figure 3-11: Environmental constraints – Bogs/Marshes
Figure 3-12: Environmental Constraints –Water Resources
Figure 3-13: Environmental Constraints – Flood Zones
Figure 3-14: Madaket/Warrens Landing
Figure 3-15: Somerset Map Layout
Figure 3-16: Hummock Pond North Layout
Figure 3-17: Hummock South Layout Map
Figure 3-18: Miacomet Layout Map
Figure 3-19: Monomoy Layout Map
Figure 3-20: Shimmo Layout
Figure 3-21: CIP
Figure 3-22: Recommended Plan Figure
Figure 3-23: Existing Surfside WWTF Discharge Beds
Figure 4-1: Capital Improvement Plan - spreadsheet 11 X17
TABLES
Table 2-1: Board of Health File Review Results
Table 2-2: Embayment Area, Present Watershed Nitrogen Loading Rate, Target Threshold Nitrogen Loading
Rate, and Difference Necessary to Achieve the Target Threshold Load
Table 2-3: Nantucket Harbor Estuary N Reductions Necessary to Meet TMDL (Table 4 from MEP)
Table 2-4: Madaket Harbor Estuary N Reductions Necessary to Meet TMDL (Table 6 from MEP)
Table 2-5: Potential Street Sweeping Load Reduction
Table 2-6: Potential Catch Basin Cleaning Load Reduction
Table 2-7: Stormwater Control Structure Load Reduction
Table 2-8: Most Feasible N Reduction Stormwater Activities and Cost Estimates
Table 2-9: MEP Fertilizer Target Load Reductions
Town of Nantucket (#225139.00)vii Woodard & Curran
Final CWMP Update Report Volume I October 2014
Table 2-10: Septic Management Plan Regulations Implemented to Date
Table 2-11: Updated Needs Areas and Area of Concern
Table 2-12: CWMP Update Matrix
Table 2-13: Phase I CWMP Wastewater Winter and Summer Wastewater Unit Flows
Table 2-14: Wastewater Load Factors
Table 2-15: Wastewater Flow and Load Ratios Based on Existing WWTF Data
Table 2-16: Average Daily Flow and Peak Hour Flow
Table 3-1: Surfside WWTF Recommended Improvements Cost Estimates
Table 3-2: Surfside Wastewater Discharge Bed Areas
Table 3-3: Woodard & Curran Calibration Statistics
Table 3-4: Summary of Surfside Wastewater Collection System Recommended Plan
Table 3-5: Ocean Outfall Opportunities and Constraints
Table 4-1: Updated Needs Areas and Area of Concern
Table 4-2: Study Areas Final Recommended Plan
Table 4-3: Surfside WWTF Final Recommended Improvements Cost Estimates
APPENDICES – Volume II
Appendix A: MEPA Certificate 2004 CWMP Data 2004 Needs Areas Matrix
Appendix B: Nantucket Zoning By-Law Board of Health Data
Appendix C: Massachusetts Estuaries Report Summaries Massachusetts Estuaries Technical Memorandum on
MOdel Run Scenarios total Maximum Daily Loads Landfill Backup Data
Appendix D: Wannacomet Water Data
Appendix E: Nantucket Sewer Act Board of Health Local Regulations Board of Health Administrative Consent
Order Septic Management Plan Documents
Appendix F: Wastewater Data Flows and Loads Calculations
Appendix G: Madaket Wastewater Natural Heritage and Endnaged Species
Appendix H: Surfside WWTF Data Capacity Analysis Technical Memorandum Energy Memo Groundwater
Discharge Permit BRP -11 BRP – 83 O&M Manual
Appendix I: Capital Improvements Plan Financing and Cost Scenarios
Appendix J: Ocean Outfall Information
Appendix K: Public Outreach Information
Town of Nantucket (#225139.00)ES-1 Woodard & Curran
Final CWMP Update Report Volume I October 2014
EXECUTIVE SUMMARY
Executive Summary
Nantucket began its Comprehensive Wastewater Management Planning (CWMP) in 2000 with the first of three
phases well underway when the Massachusetts Department of Environmental Protection (MassDEP) and the
University of Massachusetts Dartmouth School of Marine Science and Technology (SMAST) announced the
commencement of the Massachusetts Estuary Project (MEP). The MEP was a study of 89 embayment areas in
southeastern Massachusetts, the Cape and Islands. Nantucket was the subject of four such embayment area
studies; 1) Nantucket Harbor (including Polpis Harbor); 2) Madaket Harbor and Long Pond; 3) Sesachacha Pond;
and 4) Hummock Pond. The MEP was centered on evaluating the nutrient enrichment of these coastal waters,
specifically targeting nitrogen loading from various sources including the part on-site wastewater systems had in the
degradation. The 89 embayments were divided up into various phases with the first beginning in 2002. Nantucket
and Polpis Harbors were included in the first round of studies starting in July 2002. The results of these studies were
not expected to be finalized for at least two years. In reality, it took more than two years to complete. When the news
of the impending MEP studies was announced, Nantucket reached out to MassDEP for advice as to how to proceed
with the on-going CWMP due to the potential impact the MEP would have on the results carried in the CWMP.
Because the MEP studies were expected to take years to complete, Nantucket was advised to continue with the
CWMP and efforts could be coordinated during the MEP study period. Nantucket completed the three phases of the
CWMP with the Final CWMP and Final Environmental Impact Report in 2004 and the MEP studies were still pending
in all embayment areas of the Island. In hindsight, the decision between Nantucket and MassDEP to continue
moving forward with the CWMP was a good one. When Nantucket was filing the final phase of the CWMP through
the Massachusetts Environmental Policy Act Office (MEPA) in 2004, it was mandated that once the MEP studies
were completed that Nantucket would have to complete an update to its Final CWMP incorporating the MEP data into
the overall wastewater planning. Refer to Section 1 for an update of the 2004 planning.
The 2004 CWMP completed a wastewater evaluation that determined areas of the Island that were not long-term
sustainable with on-site wastewater systems. This was based on a host of criteria that included review of Board of
Health records for Title 5 failures, major repairs, multiple system pumping, soils and groundwater conditions and
potential impacts of on-site systems to environmental resources. Based on a rating criteria matrix, geographical
areas were delineated and rated as either requiring an off-site wastewater solution or able to sustain long-term with
an on-site system. At this time, there was no knowledge of the issues that would be encountered due to nitrogen
enrichment to the water resources. So the 2004 CWMP recommendations were made based on the criteria that
existed at that time. With the introduction of the MEP, nitrogen would now add to a host of diverse criteria to
determine Needs Areas.
According to the MEP, Project partners were tasked with determining the geographic area contributing nutrients to a
specific estuary; establish what the nutrient sources are, what the amount of each nutrient load is, and the maximum
nutrient load the estuaries could tolerate without dramatically changing their character and usages. In the Nantucket
case studies, returning the estuaries to the water quality condition that support sensitive shellfish habitats and lush
eelgrass beds, revealed it would be necessary to remove a significant percentage of the nutrient loadings coming
from the estuary's watershed. The MEP studies provided water quality, nutrient loading, and hydrodynamic
information for six geographic areas on Island that would need to be added to the previous data collected and an
updated CWMP be completed. This 2014 CWMP Update comes twelve years after the inception of the MEP and
over 14 years after Nantucket began the CWMP quest. This Report contains an exhaustive study of not only the
MEP results on Island, but also all that has transpired since 2004 when the Town filed its final phase of the initial
CWMP. This document satisfies the MEP update mandate, as well as updates the existing and future conditions
Town Wide in this Integrated Planning document for the next 20-years.
Town of Nantucket (#225139.00)ES-2 Woodard & Curran
Final CWMP Update Report Volume I October 2014
The various sections of this Report describe in detail the changes that have been made over the last decade and
what, if any, influence to the wastewater planning on Island was or would be realized. These include:
Completed MEP Reports
Total Maximum Daily Loads (TMDLs) Issued
Revised, Updated and New Board of Health Regulations
Watershed Updates
Updates to the Surfside WWTF Since 2004
Sewer Act of 2008
Updated Zoning
Septage Management Plan
Public Water Update
Stormwater Planning and Implementation
Fertilizer Management
Tight Tank Policy
Landfill Mining
Ocean Outfall
Climate Change
Water Quality Programs
Energy
The Report sections that follow identify the Town’s efforts in each of these areas over the last ten years since the
completion of the 2004 CWMP/EIR and how each has had an impact to the initial wastewater planning creating an
Integrated Wastewater Management Plan that will serve the Town for the next 20 years. Section 2 summarizes the
data updates completed as part of this Report.
Major highlights of this CWMP Update effort include the Capacity Analysis of the Surfside Wastewater Treatment
Facility (WWTF). The results of this study opened the door to be able to eliminate the need to plan and design a third
WWTF in the Madaket Area at the western end of the Island on the former FAA land. The Town contracted the
Preliminary Design of this WWTF in 2009 with the initial intent of designing and constructing a new WWTF to service
the Needs Areas on this end of the Island. The original scope of work was to complete the due diligence needed to
design this WWTF. This included the intensive surveys for the Natural Heritage and Endangered Species Program
(NHESP) and the Massachusetts Historical Commission (MHC). The results of the NHESP survey identified
significant challenges with the site due to the presence of both plant and animal species. With concerns for both the
environmental constraints revealed, financial hurdles in acquiring and permitting, as well as local concerns for
utilizing this site for wastewater, the Town amended the Madaket Preliminary Design scope. The amendment
directed new tasks to concentrate on the potential to utilize the Surfside WWTF for the Needs Areas initially
recommended for the Madaket WWTF.
Concurrent with the Surfside WWTF Capacity Analysis, the 2004 Needs areas were in the process of being updated
with both the MEP results where appropriate and with the afore mentioned data sets to confirm the 2004 CWMP
results and identify any new areas of wastewater concern. This task entailed an exhaustive exercise of reviewing
Board of Health files and new and/or revised Local Regulations in order to supplement the new data with that
evaluated in the original CWMP. Existing data was applied to the Needs Areas, which updated the on-site
information to 2012. Because of this exercise, a new Local Regulation was created and adopted by the Town-the
Administrative Consent Order (ACO). The ACO provides property owners with failing on-site systems the ability to
defer major repairs as long as their property is located within an approved Needs Area and sewer is proposed in the
near future. At the time of this development, Madaket Needs Area was approved to utilize the ACO, which saves the
Town of Nantucket (#225139.00)ES-3 Woodard & Curran
Final CWMP Update Report Volume I October 2014
owner from having the expense of designing and installing a major repair/replacement system and then having to pay
for sewer. The Board of Health will work with the property owner to find a temporary solution until such time as
sewer is available. This is but one solution that is a win/win for the Town and its residents. Sections 2 and 3
summarize the processes taken, including the alternatives evaluation.
Other coordination with data updates was carried on with multiple entities including Town staff and various local
groups. The result is this collaboration is a comprehensive update of areas needing an off-site wastewater solution.
This included adding three new Needs Areas in addition to confirming six from the 2004 CWMP. The complete data
update is included in Section 2.
The revised 2014 Needs Areas look like this:
Somerset
Madaket
Warrens Landing
Town Sewer District Unsewered Parcels
Monomoy
Shimmo
Hummock Pond North (New)
Hummock Pond South (New)
Miacomet (New)
The total estimated cost of servicing the Needs Areas as noted above is $198.8M. This is included in the 2014
Capital Improvements Plan detailed in Section 5 of this Report. The Needs Areas details are included in Section 2. A
CY2015 State Revolving Fund Project Evaluation Form (PEF) was filed in August 2014 to fund the first priority Needs
Areas of Somerset, Madaket/Warrens Landing.
The revised Needs Areas projected a new wastewater flow of 4.0 MGD, which was utilized as the target for the
Surfside WWTF. Surfside WWTF was upgraded in 2009 to 3.5MGD to service the needs identified in the 2004
CWMP. The task then at hand was to determine if the Surfside WWTF could support the additional 0.50MGD. The
outcome of the Capacity Analysis was positive that the facility itself could handle the additional flows, which
eliminated the need for a Madaket facility. The Capacity Analysis did uncover a number of upgrades necessary for
reliability in every day operations, upgrades to support additional flow that was not included in the 2004 CWMP and
upgrades to support energy efficiencies for savings in both the short and long term. During the Capacity Analysis,
there were some issues identified as a result of budget cuts that were taken during the last upgrade-major item was
the screening that protects the membranes. While the facility is relatively new, operations since the upgrade has
proven to show that some of the items initially cut need to be added for reliability and preservation of a major part of
the wastewater operations-the membranes. The total cost for the recommended upgrades is $8.827M. A CY2015
State Revolving Fund Project Evaluation Form (PEF) was filed in August 2014 to fund these recommendations.
Sections 3 and 4 contain all supporting information on the Surfside Capacity Analysis.
Once the WWTF was determined able to support the total revised flow, the limiting factor was the Surfside
Groundwater Discharge Permit, which was set at 3.5 Max Day. Multiple meetings ensued with MassDEP to open
discussions on the potential to modify the permit to meet the revised flow of 4.0 MGD. The discussions centered on
the ability of the 15 existing sand beds to be loaded at a higher rate than is currently done, which would support the
additional flow at full buildout. A full hydrogeological evaluation, with updated modeling of the new load rates applied
to the existing beds was completed. The results showed that the current bed system could accept the higher loads
up to 4.0 MGD. A Groundwater Discharge Permit Modification was filed and together with the Hydrogeological
Evaluation filed has been approved by MassDEP. The new permit is pending. There is no additional cost to upgrade
the permit limits as the existing physical infrastructure supports the new permit.
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The impetus for embarking on the CWMP Update was to incorporate the MEP results into the wastewater analyses
and planning. This entailed evaluating a scope of potential solutions in the embayment areas in order to develop a
sound plan to meet the Total Maximum Daily Loads (TMDLs) or water quality thresholds established in the MEPs.
This included developing and having various model run scenarios completed by SMAST utilizing nitrogen loading
results from the respective MEP Reports and compiling datasets in order to develop plans to meet the water quality
thresholds set throughout the Island. Each embayment area MEP was different and based on the specific nitrogen
loads relative to the area. This Report developed plans to meet all water quality thresholds set in the MEP and
subsequent TMDLs in an Adaptive Management Plan for each specific area; 1) Nantucket Harbor (including Polpis
Harbor); 2) Madaket Harbor and Long Pond; 3) Sesachacha Pond; and 4) Hummock Pond. An Adaptive
Management Plan was created for each area and includes both structured and non-structured solutions to meet the
established TMDLS and/or water quality thresholds set in the specific water resource.
The Adaptive Management Plan is intended to be an iterative process whereby incorporating recommended solutions
meets one or more resource management objectives and accrues data needed to determine the need for additional
future management. For example, Nantucket Harbor will realize water quality improvements as a result of the
restructuring of the jetties that are poised for completion in 2015. Will this improvement be enough to raise the water
quality in both Nantucket and Polpis Harbors where the two TMDLS are set? On the other hand, will additional
improvements be needed such as sewering Monomoy, Shimmo in order to meet the mandated thresholds here?
This is the “adapting” in the Adaptive Management Plan that will serve as a tool to change existing conditions. This
recommendation is documented in Section 4.
The above are the major highlights of the CWMP Update. There is a significant amount of other supporting data that
has been updated and is included throughout this Report. The CWMP Update summarizes all the efforts the Town
has undertaken since the completion of the 2004 CWMP in order to assess the need for additional work.
The result of this CWMP Update is a new Recommended 20-Year Plan for wastewater management. This includes
additional planning, operation and maintenance recommendations, as well as structures solutions for both Surfside
WWTF upgrades and sewering. A Capital Improvements Plan (CIP) and 20-year schedule was developed
incorporating all of the recommendations included in this Update. This CIP meets and or exceeds the requirements
of the TMDLs and or water quality thresholds established in the MEPs. All recommendations are identified in
chronological order of need and associated costs in Section 4. With the Adaptive Management Plan, the ultimate
result may in fact be a plan that costs far less than originally anticipated based on progress of actions and future
need.
Research into available funding and financing mechanisms to support the CIP contained herein are included in
Section 5. The State Revolving Fund (SRF) Program is the most probable way to finance the capital costs of the
Final Recommended Plan. Four CY2015 Project evaluation Forms (PEFs) were filed in August 2014 to fund portions
of the CIP. These include; 1) Surfside WWTF Upgrades; 2) Somerset, Madaket/Warrens Landing Sewer Extensions;
3) Stormwater Master Plan; and 4) Infiltration and Inflow Assessment. The Town will now have to work to produce a
Capital Cost Recovery Program that will be accepted by the public.
There was significant public outreach that took place that started in 2011 with the Board of Selectmen sponsored
Wastewater Action Plan. This was the precursor to the CWMP Update Public Outreach planning that has been
continuous since 2012. Refer to Section 6 for a summary of this outreach.
This CWMP Update meets the regulatory requirements set in the 2009 MEPA Certificate and delivers a Final
Recommended Plan for wastewater management for the next two decades. Nantucket is well ahead of the region
with its proactive approach to wastewater management. The overall water quality in Nantucket Town Basin in the
Harbor is a credit to the Town showing the proactive nature of the people and mainly due to the fore fathers of
wastewater who over a hundred years ago implemented the Town wastewater system. Without knowing or having
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the knowledge of what would come in the twenty first century with nitrogen load issues, this system has proven to be
the lead in maintaining water quality in this area. The Adaptive Management Plan recommended herein will follow in
these steps to assure that all areas on Island preserve and protect the water resources from further degradation and
return them to water quality standards set by each individual resource. The preservation and protection of
Nantucket’s most valuable resource, water quality, is a priority to the economic, political and overall sustainability of
this Island. The 2014 Recommended Plan is the wastewater plan that will carry this forward.
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1.CWMP UPDATE
1.1 SUMMARY OF 2004 CWMP/EIR
The Town of Nantucket completed its Comprehensive Wastewater Management Plan and Environmental Impact
report (CWMP/EIR) in March 2004. The Phase III CWMP, CWMP/FEIR was submitted through the Massachusetts
Environmental Policy Act Office (MEPA), and approved with a MEPA Certificate determining that the Phase III
CWMP/EIR filing “adequately and properly complies with the Massachusetts Environmental Policy Act (G.L., c.30,
ss.61-62H) and with its implementing regulations (301 CMR 11.00). Refer to Appendix A for all MEPA Certificates
issued on the 2004 CWMP/EIR.
The CWMP/EIR addressed the Town’s long-term and short-term wastewater management needs. The report
evaluated Island-wide methods of managing wastewater treatment and disposal. The Report also identified and
evaluated environmentally long-term sustainable wastewater management, both in treatment and disposal in order to
meet local, state and federal water quality standards, as well as standards related to public health, again at state Title
5 and Nantucket’s local standards, identified as Local Regulations, through the Board of Health. The Report included
a summary of existing conditions on Island, future conditions, identification and screening of alternative wastewater
methods, development and implementation of a public participation program and conclusions, including identifying
those areas on Island recommended for an off-site wastewater solution.
The CWMP was initiated through the filing of an Environmental Notification Form (ENF) in November 2001, which
determined that the CWMP, EOEA No. 12617, would be filed as a Special Review Procedure with the filing of three
documents:
Phase I, Needs Analysis (including Screening of Alternatives)
Phase II Draft CWMP/Draft EIR
Phase III Final CWMP/Final EIR
Phase I CMWP/EIR1.1.1
The Phase I Needs Analysis and Screening of Alternatives was filed through MEPA in August 2012. This Report
contained the results of a Town-wide Needs Analysis to determine whether or not conventional Title 5 on-site
wastewater disposal systems were long-term sustainable throughout the project life of 20 years and beyond. The
Town was delineated into 18 areas of study in order to compile specific data about the geographic area within the
ranking matrix. The rating criteria matrix was developed utilizing criteria to determine the sustainability of on-site
disposal systems using both on-site details (physical characteristics such as size of lot, soil and groundwater
conditions), as well as community information on file with the Assessor, Water Department and Board of Health
(Number of bedrooms, baths, potential for buildout, areas within watershed protection areas, number and type of Title
5 on-site system failures and/or major repairs, etc.). The data that resulted from the exercise was compiled into each
of the 18 Study Areas and were then compared using a two-stage ranking system:
First stage rated the 18 Study Areas based on the data in the Criteria Matrix1.
The second stage reviewed the results of Stage 1 and further evaluated the areas based on severity of soils2.
and groundwater conditions as they relate to the sustainability of on-site wastewater disposal systems, as
well as age of on-site system (related to life of a Title 5 system).
The 2004 CWMP final recommendation included five Study Areas as Needs Areas- areas needing an off-site
wastewater solution. These Needs Areas are:
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Madaket Warrens Landing Somerset Monomoy Shimmo
The sewer recommendation also included the complete build-out within the Town Sewer District. The remainders of
the study Areas were recommended to maintain existing on-site wastewater disposal systems managed under a
Septage Management Plan (SMP). The Town developed and adopted a SMP on November 9, 2005. Provisions
within this Plan will afford the Town to continue to monitor and manage areas where no municipal sewer is proposed.
Refer to Chapter 2, Section 2.9 of this Report for a summary for the SMP activities to date.
Refer to Appendix A for a copy of the 2004 CWMP Phase I Rating Criteria Matrix
The Phase I Report also reviewed and evaluated preliminary alternatives for wastewater including the following:
Continued use of Title 5 on-site wastewater disposal systems
Massachusetts approved on-site Innovative/Alternative Systems
Various types of wastewater collection, treatment and disposal systems
-Local
-Communal / Small Package Plants
-Decentralized
Groundwater discharge options and sites
Figure 1-1 from the Phase I CWMP details the final areas of wastewater disposal need as well as a summary of each
Study Area and its recommendation for wastewater solution.
The Phase I Report can be accessed through the Town’s website at www.nantucket-ma.gov or at the Department of
Public Works Office.
Challenge:Evaluate alternatives for a 20-year solution to wastewater collection, treatment and disposal needs of the Town.Solution:An Island-wide study to maintain and/or improve environmental conditions while determining costs, benefits for long-term sustainability, protection of the sole source aquifer and public health, and preservation of Nantucket Harbor, Madaket Harbor, Polpis Harbor and Sesachacha Pond.MadaketChallenge• Small Dense Lots• Madaket Harbor Watershed• Private Water Supply & Wastewater DisposalSolution• Decentralize Wastewater TreatmentSomersetChallenge• Small Dense Lots• Private Water & Wastewater DisposalSolution• Connect into Existing Wastewater SystemPolpisChallenge• Nantucket Harbor Watershed• Degradation of Polpis Harbor• High Groundwater• Private Water Supply & Wastewater DisposalSolution• Septage Management PlanWauwinetChallenge• Small Dense Lots• Private Water Supply & Wastewater DisposalSolution• Septage Management PlanQuidnetChallenge• Topography• Small Dense Lots • Private Water & Wastewater DisposalSolution• Septage Management PlanTown WPZChallenge• Wellhead Protection Zone• Private Water Supply & Wastewater DisposalSolution• Septage Management PlanPocomoChallenge• Nantucket Harbor Watershed• High Groundwater• Private Water Supply & Wastewater DisposalSolution• Septage Management PlanMonomoyChallenge• Nantucket Harbor Watershed • Private Water Supply & Wastewater DisposalSolution• Connect into Existing Wastewater System ShimmoChallenge• Nantucket Harbor Watershed• Private Water Supply & Wastewater DisposalSolution• Connect into Existing Wastewater SystemWarrens LandingChallenge• Madaket Harbor Watershed• Small Dense Lots • Private Wastewater DisposalSolution• Decentralize Wastewater TreatmentArea of Wastewater Disposal NeedArea of Wastewater Disposal Need Based on Wellhead Overlay Protection ZoneArea of Wastewater Disposal Need Based on Harbor Watershed LinePrepared For: Town of Nantucket, Department of Public Works, 188Prepared For: Town of Nantucket, Department of Public Works, 188Madaket Road, Nantucket, MA 02554Madaket Road, Nantucket, MA 02554For Additional Information Contact: Mr. Jeffrey Willett, DirectoFor Additional Information Contact: Mr. Jeffrey Willett, Director, Department of Public Works, 508r, Department of Public Works, 508--228228--72447244Prepared By: Earth Tech, Inc., 196 Baker Avenue, Concord, MA 017Prepared By: Earth Tech, Inc., 196 Baker Avenue, Concord, MA 01742, Contact: Mr. Thomas Parece, P.E., 97842, Contact: Mr. Thomas Parece, P.E., 978--371371--41424142Date Prepared: June 2003Date Prepared: June 2003SiasconsetCurrently SeweredTownCurrently SeweredRemainder of IslandSeptage Management Plan
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Phase II CWMP/Draft EIR1.1.2
The Phase II CWMP/EIR, EOEA No. 12617, was filed and approved through MEPA in September 2003. This Report
contained responses to the comments received on the Phase I CWMP, as well as an evaluation and screening of all
potential treatment alternatives and groundwater discharge sites that could address the needs identified in the Phase
I CWMP. A number of Massachusetts approved alternative treatment technologies were evaluated and detailed,
including an option of continuing to utilize on-site Title 5 systems.
The Phase II Report also reviewed opportunities to reduce wastewater flows, potential wastewater reuse alternatives
and disposal options for residuals. This information is contained in full within Chapter 3 of the Phase II Report. A full
screening of sites on Island was evaluated for the potential discharge of highly treated wastewater; similar to how the
Town currently operates the Surfside Wastewater Treatment Facility and Siasconset Wastewater Treatment Facility
discharge beds. Figure 2-12 from the Phase II CWMP Report detailing the sites follows here as Figure 1-2.
The Draft Recommended Plan contained in Chapter 5 of the Phase II CWMP proposed to sewer the following Needs
Areas:
Madaket and Warren’s Landing Needs Areas
-Design and install a satellite WWTF on the former FAA Site on Red Barn Road
-Low-Pressure sewer
Somerset Needs Area
-Connect into Surfside WWTF
Shimmo
-Preliminary to connect into Surfside WWTF. Finalize after review of Massachusetts Estuaries Report
results
Monomoy
-Preliminary to connect into Surfside WWTF. Finalize after review of Massachusetts Estuaries Report
results
Town
-Continue to build out the Town Sewer District (TSD) into the Surfside WWTF
The following Study/Needs Areas were recommended for maintaining current on-site systems under a Septage
Management Plan:
Cisco Miacomet
Surfside Tom Nevers Low Density Areas
Tom Nevers-High Wauwinet
Pocomo Polpis
Quidnet Town WPZ*
*With the caveat that should any impacts to Town well area arise, this area will be connected to sewer at Surfside WWTF
Figure 1-2
2004 CWMP Needs Areas and Alternative site Locations
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The Phase II CWMP Report also detailed necessary upgrades to the Surfside WWTF to accommodate the flows and
loads associated with the existing Town Sewer District (and build-out) , as well as the Needs Areas identified in the
Report.
A comprehensive public outreach program was on going throughout the project duration in order to educate the
public as to the CWMP process and solicit comment from the interested parties.
The Phase II Report can be accessed through the Town’s website at www.nantucket-ma.gov or at the Department of
Public Works Office.
Phase III CWMP/Final EIR1.1.3
The Phase III CWMP/EIR, EOEA No. 12617, was filed and approved through MEPA in May 2004. This was the Final
CWMP and Final Environmental Impact Report (CWMP/FEIR). This Report contained responses to the comments
received on the Phase II CWMP, as well as final evaluation of the Draft Recommended Plan included in the Phase II
Document. The Final Recommended Plan to sewer specific Needs Areas as noted above, were evaluated
environmentally, as well as financially, detailing individual household costs should the Plan be implemented. A
complete review of the existing staffing levels at the Department of Public Works was reviewed with
recommendations for preparing for an expanded wastewater collection and treatment system. There were specific
recommendations in order to operate and maintain the entire wastewater collection, treatment and disposal system in
order to meet the proposed new demands.
A review of the then current sewer user charge system, sewer system expansion control and potential flow reduction
options were evaluated and summarized.
The 2004 CWMP/FEIR is the basis for this CWMP update. The Town moved forward with many of the 2004 CWMP
recommendations with the largest project completed the upgrade to the Surfside WWTF. The CWMP/FEIR was
completed without having the benefit of having the MEP results and thus was mandated by MassDEP to update once
the MEP Reports and any subsequent Total Maximum daily Loads (TMDLs) issued. It is under this direction that this
Report is underway with the result being this Report.
A Capital Improvements Program (CIP) was completed as part of the Phase III CWMP that detailed the report
recommendations in a chronological calendar and associated costs per recommendation. This CWMP Update has
updated the 2004 CIP, which is included in Section 4 - Final Recommended Plan of the Phase III CWMP/FEIR
Report. Figure 1-1, shown previously, details the Final Recommended Plan from this Phase III Report.
The Phase III Report can be accessed through the Town’s website at www.nantucket-ma.gov or at the Department of
Public Works Office.
Summary of Massachusetts Estuaries Program1.1.4
The Massachusetts Estuaries Program (MEP) is a collaboration between the Massachusetts Department of
Environmental Protection (MassDEP) and the University of Massachusetts Dartmouth School of Marine Science and
Technology (SMAST). The MEP was initiated to evaluate nitrogen sensitivity in coastal embayments in southeastern
Massachusetts, Buzzards Bay, Cape Cod and the Islands of Nantucket and Martha’s Vineyard. The MEP is being
completed through comprehensive water quality sampling/testing and quantitative Total Maximum daily Load (TMDL)
modeling. The data from the analysis is utilized to prepare technical reports that detail the analysis process and
present final results of areas where nitrogen lading is an issue, what is causing it and providing communities with
“locally controllable” solutions for reducing the nitrogen loading that will provide solutions to meet the TMDLs
established in the area.
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The MEP was initiated in July 2002 with a list of 89 embayment areas; Nantucket was included in the list with five
embayments; Nantucket Harbor (included Polpis Harbor), Sesachacha Pond, Madaket Harbor, Long Pond and
Hummock Pond. The first round of studies started in 2002 encompassed 20 embayments, with Nantucket having two
areas of study in the first round:
Nantucket Harbor (#13)Sesachacha Pond (#18)
Both of these MEP Projects were started during the 2004 CWMP, but had just started gathering data and were not
near completion in 2004 when the CWMP was ready for finalization. Discussions with MassDEP resulted in a
determination that it was best to continue moving the CWMP forward and the Town would be required to incorporate
the final results of the MEP into a CWMP Update at some point in the future. This would include providing a
recommended solution to meet the TMDLs issued. This CWMP Update Report is the result of this mandated review.
Round 2 of the MEP was started in July of 2003 with 14 additional embayment areas and included two more areas in
Nantucket:
Madaket Harbor (#12)Long Pond (#13)
The last watershed to be studied on Island was Hummock Pond, which was eliminated from the original list of 89 due
to the lack of available state funds to subsidize. Nantucket, being a proactive community when it comes to water
resource issues, particularly water quality, was quick to respond that the Town itself would partner directly with
SMAST in order to get the Hummock Pond MEP started. In October 2012, the Town entered into a contract with
SMAST to initiate the start of the MEP for Hummock Pond. The timing was crucial as the CWMP Update was in
process and the Town wanted to incorporate all MEP studies into the final report. Because the Town was diligent in
its annual water quality testing and had over two years of previous water quality data on Hummock Pond, it was
determined that the MEP could be accomplished before the final CWMP update was delivered. So, the final round of
MEP for Nantucket included:
Hummock Pond
In addition, the Town is including a study of Miacomet Pond to round out the nutrient studies of larger Island
watersheds. A fresh water system and not an area subject to nitrogen loading, there are concerns based on historical
water quality testing results, as well as issues with flooding that have prompted the Town to pursue a separate
contract to look at Miacomet’s specific issues. While Miacomet is a fresh-water body and not the subject of nitrogen
loading, it will be studied and evaluated in order to document the chronic issues the Pond is facing and detailed
recommendations to provide solutions to eliminate or provide relief from those chronic issues will come forward in the
future.
Chapter 2 provides more detailed discussion on the MEP studies and specific results for each area.
Overall 2004 CWMP/EIR Summary1.1.5
The 2004 CWMP addressed the long-term and short-term issues relating to the Town’s wastewater and disposal
needs. The Report examined the full range of the Town’s needs and identified environmentally sustainable
wastewater collection, treatment and disposal alternatives that at that time met the Town’s needs while also meeting
local, state and federal water quality and public health standards. The Report summarized existing and future
conditions in the Town and developed a 20-year plan to meet the local needs. At the same time, the recommended
plan met the state’s goal of sustainable growth, which looked at resource protection and met the local and state
sustainable economic development.
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The upgrades at the Surfside WWTF were initiated in 2005 and included the construction of five additional sand beds
for effluent disposal, which was a direct result of recommendations in the 2004 CWMP, as well as contained in an
Administrative Consent Order (ACO). Although no new Needs Areas have been designed and constructed and thus
sewered since the 2004 CWMP, other portions of the 2004 CWMP have been implemented. The Town embarked on
an aggressive Infiltration and Inflow (I/I) removal program. This I/I Program is an on-going process that is driven by
the need for flow reduction, which is part of the 2004 MEP Certificate recommendations. Currently, the Town is
working on Phase 2B working in the downtown area to identify and correct extraneous water filtering into the
municipal sewer system.
The Stormwater Drainage and Outfall Evaluation Project was completed in 2005 to document and map all drainage
outfalls in Town. This Project was a mapping exercise only and did not include a coordinating, documented report. A
future recommendation included in this CWMP Update is to complete a Stormwater Master Plan that will provide the
Island-wide data to support the 2005 mapping exercise. The Town filed and was approved in the CY2014 Project
Evaluation Form (PEF) for State Revolving Funds to complete a Stormwater Master Plan Island-wide and
supplement this information to the completed mapping exercise. The Town decided to defer this project until the
CWMP Update was finalized. A CY2015 Project Evaluation Form (PEF) will be re-filed in August 2014 for the
Stormwater Master Plan, which can then be started late 2015 or early 2016. The project will then have information
relative to stormwater and the MEP and subsequent TMDLs to evaluate as part of the overall plan.
The Final Recommended Plan contained in the 2004 CWMP contained areas where there were preliminary
recommendations as to how a Needs Area would be treated, but also contained language that stated the final
recommendations would be presented based on the MEP study results.
The MEP results for all embayment areas are now complete, with Hummock Pond being the most recent in late
2013. The subsequent chapters of this CWMP Update the 2004 CWMP with a new, comprehensive plan that serves
to meet not only the requirements set forth in the 2004 MEPA Certificate, but all current local, state and federal
standards. The final chapter in this Report details a revised Final Recommended Plan that should serve to meet the
needs of the Town for a 20-year planning period. This Final Recommended Plan also includes provisions contained
in an Adaptive Management Plan that specifically address the MEP studies and results in order to develop a plan to
meet the Massachusetts Department of Environmental Protection issued Total Maximum Daily Loads (TMDLs) in
multiple areas on Island.
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2.DATA COLLECTION AND REVIEW
This section presents information and data from all pertinent documents developed and issued between 2004, the
completion of EOEA 12617 CWMP/FEIR, and present, that relate to wastewater and stormwater planning. These
updates are necessary to address the time lapse between the 2004 CWMP/FEIR and this Report. Pertinent
documents include regulations, zoning changes, by-law changes and additions, regulatory changes, ongoing water
quality testing and analysis results, and MEPA’s review of the 2004 CWMP/FEIR.
2.1 UPDATE TO NEEDS AREAS
As part of the August 2001 Phase I CWMP, the Town was delineated into 18 study areas based on geographic
location and neighborhood land uses. A Town-wide Needs Analysis was performed to determine whether or not
conventional Title 5 septic systems would be long-term sustainable in disposing of wastewater throughout the 20
year planning period. The Analysis included data from the Board of Health records, Assessor’s files, Geographic
Information Systems (GIS) records, and USDA soils and groundwater data. The 2004 CWMP/EIR identified five
geographic areas, determined as Needs Areas, defined as not long-term sustainable with on-site wastewater
disposal systems. These Needs Areas include:
Madaket Warrens Landing Somerset
Monomoy Shimmo
Also included in the above Needs Areas is the full build-out for the existing Town Sewer District where the majority of
parcels are currently connected to the municipal wastewater system at Surfside WWTF.
As part of developing this CWMP Update, W&C worked with multiple entities of the Town to update the 2004 Needs
Areas with supplemental data derived within the period of when the 2004 CWMP was finalized and 2012/2013 – an
eight to nine year period when many changes were adopted on Island. These changes include the following:
Completed Massachusetts Estuaries Reports Total Maximum Daily Loads (TMDL) Issued
Revised Board of Health Septic Regulations Revised Zoning Regulations
Nantucket Sewer Act of 2008 Surfside WWTF Capacity Analysis
MEPA Greenhouse Gas Emissions Policy Stormwater Planning
Landfill Mining Innovative/Alternative Technologies Update
Septage Management Planning Fertilizer Management Plan
Board of Health – Administrative Consent Order Tight Tank Policy
Sewer Connection Policy Infiltration / Inflow Program Update
Potable Water Update Energy Program
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Surfside WWTF Capacity Analysis Funding / Financing Planning
Figure 2-1 details all the components of this Integrated Planning. (Bubble Chart)
2.2 ZONING
Since 2004, the Town’s Zoning Bylaw (Chapter 139 of the Nantucket Code) has been amended, resulting in a
reduction to the number of potential second dwelling units in a number of areas on Island. In December 2006, the
then Sewer Advisory committee submitted the “Report of Recommendations from the Sewer Advisory Committee to
the Nantucket Board of selectmen, December 13, 2006”. The Report contained three major goals that were derived
from the state-approved 2004 CWMP with one goal relating to zoning. The Committee was cognizant of the fact that
future availability of centralized wastewater into areas that relied on on-site wastewater treatment may have an
impact on future development potential. While the availability of municipal wastewater versus on-site wastewater
could impact future development potential, it is the Town zoning that should drive how an area is built out. With this
fact in mind, the Committee made specific zoning recommendations to the Board of Selectmen.
The 2006 Report outlined three major goals for the Board’s consideration, with Goal No. 2 directed to zoning:
“Goal 2: Formulate recommendations on how best the Board of Selectmen may comment upon or
sponsor specific zoning articles which would increase or decrease potential flow or density with the
Sewer Districts or Needs Areas”.
The Board of Selectmen were receptive to this recommendation and through the efforts of the Board and the Town
Planner, developed revised zoning that was widely accepted and adopted in the areas of the Sewer Districts and
Tributary Areas. This proactive approach in 2006 has led to vast improvements in this CWMP Update with reduced
flows and loads overall.
We worked with the Nantucket Planning and Land Use Services (PLUS), including the GIS Department, in attaining
the new, revised zoning data. The new zoning data was overlaid onto parcel data for each of the Study and Needs
Areas in order to establish a basis for developing current and future wastewater flows and loads. The results were
compared to results from the 2004 CWMP in applicable areas and the result was in fact a reduction in flow estimates.
In addition, the revised zoning was evaluated in order to estimate the number of future second dwellings that needed
to be accounted for in the overall flows and loads estimates. Because the Town had solid zoning data, the second
dwelling estimate was more finitely defined in this CWMP Update versus the 2004 CWMP. In the 2004 CWMP,
second dwellings were estimated using a flat calculation-it was estimated that 2/3rds of all properties would have
second dwellings. In this CWMP Update, the zoning was overlain onto GIS and utilizing set formulas for each parcel,
first to determine if the existing parcel met current zoning, and then reviewing the data to see if zoning and land area
met requirements for second dwelling. Once this data was confirmed, a formula was applied based on discussions
with the Nantucket PLUS. According to PLUS, historically, 12 percent of properties have constructed second
dwellings. We applied a little more conservatism with this and applied a 25 percent formula-that based on future
build-out conditions where a parcel met zoning and land area requirements, 25 percent of these properties would
construct second dwellings. Appendix B includes a copy of the Zoning Bylaw and a list of the removals and additions
to the number of potential dwelling units by area (updated through the changes approved at 2012 Annual Town
Meeting and through the Fiscal year 2011 Land Bank acquisitions).
2.3 BOARD OF HEALTH FILE REVIEW
Woodard & Curran (W&C) conducted a review of Board of Health records and files to supplement the 2004
CWMP/FEIR with data for on-site wastewater disposal systems operations and management between 2004 and
Town of Nantucket (#225139.00)2-3 Woodard & Curran
Final CWMP Update Report Volume I October 2014
2012 to continue to support the Needs Areas from the 2004 Report, as well as to evaluate areas outside of the 2004
study that appear to be experiencing on-site issues and potentially needing alternative wastewater disposal solutions.
Since 2007, the Town has undertaken an inspection program for all parcels with on-site wastewater disposal systems
in the defined Watershed Protection Districts based on Local Regulations under the jurisdiction of the Board of
Health. . W&C staff reviewed these records, as well as other Board of Health files, for information on the timing of
inspections, results of inspections, system pumping data, and other pertinent data contained on file. The Board of
Health file review focused on a review of the 2004 Needs and Study Areas, as well as two new Study Areas;
Hummock Pond North and Hummock Pond South (in 2004 referred to as the Cisco Study Area). The need for review
and evaluation of the Hummock Pond Study Areas came about due to the history of annual water quality testing
results that were showing this area to be nutrient degraded. The Town adopted the Hummock Pond Watershed Area,
under Local Regulation 55.00, with a mandate for Title 5 inspections to determine the extent that on-site wastewater
disposal systems are contributing to the nutrient enrichment of the water resources in this area. In addition, a number
of residents in these geographic areas have been very vocal about the need for review of the on-site systems
operations and a potential need for an alternative wastewater option.
The file review looked at the entire Island, specifically areas where Title 5 Inspections have yielded failures in order to
see if any specific area stood out as having dense issues. There were no such areas that stood out, so a general
review Island-wide was completed. This exercise, while able to pinpoint areas of interest, is only as good as the data
on file. There is a certain amount of “gray area” with this review as not all issues with on-site systems are reported
and/or documented. There are additional means of support for this evaluation including a thorough review of the
Town’s Annual Water Quality Testing results, finalized MEP Reports, soils and groundwater data through MassGIS
and the United States Soils Conservation Service, and the results of the cumulative criteria analysis is included in the
matrix. Additionally, we spent a considerable amount of time reaching out to others on Island that have a keen
perspective into this issue and took much of what we gathered into consideration in the overall analysis.
Table 2-1 and Figure 2-2 present a summary of the results of the file review. Appendix B includes a list of the files
reviewed by parcel map-block-lot, including dates of inspection where known, results of inspection and other
comments and notes.
ComponentsOf Integrated Plan
Stormwater Master Plan
Current Zoning Regulations
MEPs / TMDLs
AdditionalTMDLModel Runs
Marine & Coastal Department Water Quality Testing
Landfill Mining
Septage Management Plan
New Septic Regulations Updated Capital Improvements Plan
Comprehensive Water Resources Management Plan
Fertilizer Management Plan
ACO Septic Policy
Funding/Financing
2004 CWMP Update
Energy Efficiency & Conservation
I/ATechnologies Update
Hummock Pond MEP/TMDL
Water System Expansion –Aquifer Protection
Surfside WWTF Capacity Analysis
Greenhouse Gas Policy
Tight Tank Policy
Sewer Connection Policy
Roadway/Drainage Preventative Maintenance
Stakeholder / CitizenAdvisory Participation
Madaket Sewerage
Regulatory Meetings MassDEPApprovals
Nantucket Sewer Act Implementation
MEPA– Notice of Project Change
Sesachacha Pond MEP Plan
Nantucket Harbor Flushing
Institutional Impacts
Sewer System Rehabilitation
I/I Update
.
Legend
Pond
Wetland
Board of Health Septic Records
Result
Condition Pass/Fail
Certificate of Compliance
Fail
I/A System
New system
Pass
COMPREHENSIVE WASTEWATERMANAGEMENT PLAN UPDATETOWN OF NANTUCKET, MAUPDATE TO BOARD OFHEALTH DATAFIGURE 2-2
SCALE: 1" = 1.25 MILES
DATE: FEB. 2014 JOB NO.: 225139
DOC: BOHUpdate.MXD
DRAWN BY: JSM/RTB SOURCE: MassGIS & Town
Shimmo
Monomoy
Miacomet
SiasconsetCurrently Sewered
TownCurrently Sewered
HummockSouth
HummockNorth
Warren'sLanding
Madaket
Somerset
PLUS
Town of Nantucket (#225139.00)2-5 Woodard & Curran
Final CWMP Update Report Volume I October 2014
Table 2-1: Board of Health File Review Results
Area
Total
Number of
Records
Reviewed Pass Fail
Conditional
Pass/Fail
I/A
System
New
System
Certificate
of
Compliance
No
Issue
No
Record
Hummock Pond North
Study Area 243 31 5 1 89 117
Hummock Pond
South Study Area 94 15 5 3 55 16
Miacomet Need Area 78 14 4 3 12 3 42
Pocomo Need Area 15 13 2
Somerset Need Area 122 15 2 20 14 71
Shimmo Need Area 8 3 3 2
Warrens Landing
Need Area 49 37 5 2 5
Madaket Need Area 90 65 25
Monomoy Need Area 15 4 11
Polpis Need Area 16 2 14
Wauwinet Need Area 4 4
2.4 MASSACHUSETTS ESTUARIES PROGRAM (MEP)
As was mentioned in the previous chapter, the MEP was initiated in July 2002 with an original list of 89 embayment
areas (eventually 19 embayments would be dropped from the study due to budget constraints). Nantucket was
included in the list with five embayments; Nantucket Harbor (included Polpis Harbor), Sesachacha Pond, Madaket
Harbor, Long Pond and Hummock Pond (which was one of the 19 dropped from review). The MEP started after the
Town embarked on the CWMP Special Review Procedure, with the CWMP in full swing far ahead of any MEP
results. As it stands, the CWMP was completed and approved in 2004, with the first of the MEP Reports, Nantucket
Harbor (including Polpis Harbor), completed in November 2006. The 2004 CWMP Final Recommended Plan was
completed utilizing a myriad of criteria, both physical and environmental, but was limited as to applying any of the
nitrogen criteria driving the MEP. Several meetings with regulatory officials were held in 2002 during the 2004 CWMP
process to determine if and how Nantucket was to proceed with the CWMP. The big question was, should Nantucket
stop the CWMP process and wait until the MEP was completed. Based on the fact that the MEP was very early in
process and would take an estimated two-year period to complete, it was decided that the CWMP should continue
and the Town would prepare an update to include the final MEP results when finished. In hindsight, this was a very
smart decision for a number of reasons. One, the Town was under an ACO for its Surfside WWTF, which was
addressed and completed on time (2005) and second, the CWMP was completed over two years ahead of the first
MEP in Nantucket Harbor, with Sesachacha Pond finalized November 2006 and Madaket Harbor and Long Pond not
completed until November 2010. Hummock Pond, which was due to be studied on the last round of MEP, was
dropped from the list due to state budget constraints. Nantucket, being a proactive community, was in discussions on
updating the 2004 CWMP because not only were MEPs completed, but subsequent Total Maximum Daily Loads
(TMDLs) had been issued to the Town mandating solutions to meet new water quality standards. During scope
discussions, it was decided that if the Town was going to update the 2004 CWMP, it wanted to be comprehensive
and include addressing ALL embayment areas and not have to repeat the process if sometime in the future,
Hummock Pond was added back to the study. The Town progressed with plans to fund the study independent of the
state MassDEP portion so the CWMP Update would be comprehensive in its approach to its 20-year planning. With
funding in hand, a contract was signed between the Town and the University of Massachusetts Dartmouth, School of
Town of Nantucket (#225139.00)2-6 Woodard & Curran
Final CWMP Update Report Volume I October 2014
Marine Science and Technology (SMAST) and the Hummock Pond Study was initiated in summer 2012. Copies of all
MEP Reports Summaries and TMDLS are included in Appendix C. Full Reports can be accessed on the Town’s
website at http://www.nantucket-ma.gov/132/Water-Quality-Initiative.
The Town now has four completed MEP reports encompassing six geographical embayments:
Nantucket Harbor Polpis Harbor
Madaket Harbor Long Pond
Sesachacha Pond Hummock Pond
These Studies are part of the overall coastal embayments throughout Massachusetts and are nutrient driven-namely
studying the impacts of embayment areas due to nitrogen loading from various sources. The nutrient enrichment is
basically due to land use changes-increasing building, population densities and human interactions with the land.
Rising nutrient levels are causing a decline in the ecological health of the estuarine systems leading to loss of
eelgrass beds, fisheries habitat and impacting the benthic communities. As nutrient levels continue to increase, the
overall water resources in the area start to show the degradation aesthetically with visual impacts including dense
algae blooms, which will begin to inhibit recreational resources in the watersheds.
Nutrient degradation is generally contributed through multiple channels including:
Atmospheric deposition – what is deposited through the atmosphere, i.e. pollution from power plants
Wastewater – from on-site wastewater disposal systems leaching into groundwater
Fertilizer – from over fertilizing of lawns, golf courses, cranberry bogs, etc.
Stormwater – surface water runoff from roadways, roofs, impervious areas
Water Body Surface Areas – direct precipitation to surface water resources
The major focus of the MEP Projects was to develop site-specific nitrogen load thresholds-how much degradation
can the watershed take and continue to maintain water quality standards (Total Maximum Daily Load-TMDL). Then
utilizing the site specific data, develop a plan to mitigate the nutrient loading in excess of the TMDL. The following
sections detail each individual MEP Report with identification of the MEP study locale, detail the sub-watersheds,
identify the site-specific nitrogen load contributors and finally develop a plan of action that is implementable by the
Town and meets the water quality standards in the watersheds. The MEP Reports evaluated the surface and
groundwater flows in each watershed and sub-watershed as they are the pathways for transfer of these land-sourced
nutrients to the coastal waters. The MEP “Linked Watershed-Embayment Model” provides a quantitative approach
for determining an embayment’s; 1) nitrogen sensitivity; 2) nitrogen threshold loading levels (TMDL); and 3) response
to changes in loading rate.
The main focus of the MEPs is the protection, preservation and restoration of coastal embayments from nitrogen
loading and its overall impact to the environment.
The completed MEP Reports can be found on the Town’s website at http://www.nantucket-
ma.gov/Pages/NantucketMA_NatRes/waterquality.
Town of Nantucket (#225139.00)2-7 Woodard & Curran
Final CWMP Update Report Volume I October 2014
Nantucket Harbor and Polpis Harbor MEP2.4.1
The Final Report titled, “Linked Watershed Embayment Model to Determine Critical Nitrogen Loading Threshold for
the Nantucket Harbor, Town of Nantucket, MA” was issued in November 2006. This estuary includes Nantucket
Harbor and Polpis Harbor. The system’s geographic location is on the Island’s northern shore bounded by water from
Nantucket Sound. See Figure 2-3 from the MEP (Figure I-1 in MEP) that shows the locale of the study.
The Nantucket and Polpis Harbors MEP Report summarizes the study results’ as stating that Nantucket Harbor
appears to have reached its nitrogen loading threshold, the level of nitrogen input that a system can tolerate without
showing a decline in habitat quality. As the Harbor has not yet reached build-out conditions (all developable parcels
developed and thus increased nitrogen loading), the Town needs to plan for nitrogen management now and in the
future. The Nantucket Harbor system is described as a complex estuary made up of a large lagoonal estuary
(Nantucket Harbor), with basins running parallel to the watershed that was formed behind a barrier beach (Coatue).
The system also includes Polpis Harbor, which is separated into an east and west system that receives surface water
inflow from various smaller creeks and brooks as well as wetlands.
Nantucket Harbor was divided into five sub-systems that are all different as far as the roles they play in the overall
Harbor, their flushing abilities, and where their nutrient loading impacts come from. The major sub-embayment in the
Nantucket Harbor system is Polpis Harbor, which is directly connected to the larger Harbor system. The physical
layout of Polpis Harbor is a much more closed embayment that does not receive the flushing from Nantucket Sound
that the Town Basin receives, which makes this sub-embayment more sensitive to the human impact of nutrient
loading, specifically Nitrogen. The other three subsystems are Town Basin, Quaise and Head of Harbor. These are
delineated in Figure 2-4 (Figure III-1from the MEP Report).
The MEP Report completed for Nantucket Harbor identifies the Nitrogen loadings to the Harbor as wastewater,
fertilizers, impervious surfaces, water body surface area and atmospheric deposition - see Figure2-5 (Figure IV-4
from MEP). The MEP also details those contributors that can be controlled under local regulatory control as on-site
wastewater disposal systems, fertilizers and impervious surfaces. Atmospheric deposition - nutrients received
through the atmosphere cannot be controlled, nor can the water body surface areas themselves. In evaluating
solutions to reduce the Nitrogen loading to the receiving waters, we are looking towards the locally controllable
means. Refer to the Figure 2-5 for a description of the Nitrogen loadings from the MEP Report:
Model Run Scenarios2.4.2
As part of the original MEP Report, model run scenarios were completed to determine potential Nitrogen reduction
approaches in order to meet the TMDL(s) established as a result of the MEP. It is noted that there are two Sentinel
Stations where reductions must be met due to Polpis Harbor being so closed off from the Nantucket Harbor system.
For the 2006 Nantucket Harbor MEP, two scenarios were completed to showcase different approaches to meeting
the Nitrogen reduction to maintain water quality thresholds established in the MEP. The first scenario looked at
removing 100 percent of the present (no build-out) septic load from the Town Watershed, as well as removal of 80
percent of the septic, fertilizer and impervious surfaces from the remaining Basins. The second scenario looked at
removing 100 percent of the septic from all Basins. While a significant reduction was observed, these two scenarios
are not realistic due to the extent of sewering that would be needed and the lack of availability of sewer capacity to
service the entire watershed. The TMDL solution needs to look at realistic and implementable solutions-those
measures that the Town can afford- technically, politically and economically in order to bring about a sound solution.
Figure 2-3
Nantucket Harbor Estuary
FIGURE 2-x
Nantucket Harbor Sub-WatershedsFIGURE 2-4
Nantucket Harbor Sub-Watersheds
Figure 2-5
Nantucket Harbor Land Use Specific Nitrogen Load
Town of Nantucket (#225139.00)2-11 Woodard & Curran
Final CWMP Update Report Volume I October 2014
The Town worked with SMAST to run more appropriate (realistically attainable) scenarios to evaluate options for
meeting the required Nitrogen reductions. In January 2012, the Town received the results of four model scenarios
that were more likely to meet and achieve the Nitrogen reduction, as well as be implementable locally.
The four model run scenarios, developed under existing conditions, are as follows:
Scenario 1 – Sewering the Monomoy Needs Area (as shown delineated in the 2004 CWMP and included in the
2012 TM). This includes ONLY the currently developed lots and no future build-out.
Scenario 2 – Sewering the Monomoy and Shimmo Needs Areas (as shown delineated in the 2004 CWMP and
included in the 2012 TM). This includes ONLY the currently developed lots and no future build-out.
Scenario 3 – Elevating the Jetties – exclusive of any land-based solutions
Scenario 4 – Sewering Monomoy/Shimmo AND raising the jetties in the Harbor - combination of sewering the
two Needs Areas as delineated in the 2004 CWMP in conjunction with raising the jetties. This includes ONLY the
currently developed lots and no future build-out.
All scenarios above result in lower Nitrogen levels in the Harbor; with the Nantucket Harbor station meeting the
requirements of one of the two TMDLs established by MassDEP (threshold Nitrogen levels at both sentinel stations
located in Nantucket Head of Harbor and East Polpis Harbor. See Figure 2-6 for map of Sentinel Stations).
These model runs show that sewering alone (as in the scenarios above) in the Nantucket Harbor area will not meet
TMDLs established at either the Nantucket Harbor or East Polpis sentinel stations. These scenarios were evaluated
under existing conditions and did not take future build out into consideration. The TMDLs require Nitrogen reductions,
as in the following Table, in order to meet the maximum Nitrogen load allowed in order to maintain required water
quality as per threshold established:
Table 2-2: Embayment Area, Present Watershed Nitrogen Loading Rate, Target Threshold Nitrogen
Loading Rate, and Difference Necessary to Achieve the Target Threshold Load
Embayments
Present Watershed Load
1 (kg/day)
Target Threshold
Watershed Load 2
(kg/day)Difference
Head of Harbor 1.86 0.79 1.07
Quaise Basin 2.12 1.14 0.98
Town Basin 12.22 10.71 1.51
Polpis Harbor 3.52 2.18 1.34
TOTAL 19.72 kg/day 14.89 kg/day 4.9 kg/day
1 Composed of combined fertilizer, runoff, on-site wastewater disposal system loads and atmospheric
deposition to natural surfaces.
2 Target threshold watershed load is the load from the watershed needed to meet the target threshold Nitrogen
concentrations. See Figure below for graphic of this text. Refer to Figure on Page 3 for Sentinel Station
locations.
Table 2-2 clearly shows that a reduction of 4.9 kg/day of Nitrogen in Nantucket Harbor at the two sentinel stations
(Head of Harbor and East Polpis) is needed to meet the target threshold - the maximum Nitrogen loading allowed in
order to maintain required water quality. Based on this 4.9 kg/day, the Town evaluated projects that can reduce the
Nitrogen loading in the overall Harbor that will reach this goal.
Town of Nantucket (#225139.00)2-12 Woodard & Curran
Final CWMP Update Report Volume I October 2014
Figure 2-6 (Figure VI-1 from MEP Report) shows the sentinel station locations (both SMAST and Town) where water
quality data was collected and evaluated to attain the results previously stated. The TMDL is measured at Sentinel
Stations 2A for Nantucket Harbor and 4 in Polpis Harbor.
The two scenarios detailed below showing promise in their ability to reduce the Nitrogen loading in the overall Harbor
System are Scenarios 3 and 4. One is only the tidal flushing - which is not a land-based solution, but could provide a
cleansing action by flushing fresh tidal water further into the Harbor thus removing nutrients as the tide flows back out
to sea. The other deals with removing wastewater from the Harbor (a controllable source of Nitrogen) and adds a
tidal flushing solution with the wastewater removal. These scenarios are:
Scenario 3 – Raising the jetties without any land-based solution (no sewering in Monomoy or Shimmo)
attains the threshold Nitrogen level of the May 12, 2009 established TMDL at the sentinel station at the
Head of the Harbor (Sentinel Station 2A) and comes very close to attaining the Nitrogen threshold level at
East Polpis (Sentinel Station 4).
Scenario 4 – Sewering existing properties in Monomoy and Shimmo AND raising the jetties meets the
TMDL established in Nantucket Head of Harbor (Sentinel Station 2A), but does not meet the TMDL
established in East Polpis This solution comes very close to meeting both TMDLs, but falls just shy in
meeting the TMDL established in East Polpis (Sentinel Station 4). Again, this is but one solution evaluated
in this scenario and needs to be further explored.
The additional work completed by SMAST in Scenario 1, adding full build - out of all developable lots in the Monomoy
Needs Area and sewering currently existing AND build-out parcels, results in the same as sewering existing
dwellings in Monomoy and Shimmo (Scenario 2). So, it could be assumed that, if the Town continues sewering
Monomoy AND sewers future developable parcels in this Needs Area, while also raising the jetties, both Nitrogen
threshold levels (Nantucket Harbor and East Polpis Harbor) are closer to being met.
In summary, these are four “scenarios” and their respective results in attempting to reduce the Nitrogen loading to
Nantucket Harbor by 4.9kg/day.
In February 2014, four additional scenarios were modeled with each of these under build-out conditions. These
include:
Update historically sewered parcels and update all changes with Town Sewer District (new, existing parcels)1.
Update historically sewered parcels and update all changes with Town Sewer District (new, build-out2.
parcels)
Dredge entrance to Polpis Harbor and raise the jetties to ACOE specifications3.
Dredge entrance to Polpis Harbor, elevate jetties to ACOE specifications and sewer Monomoy4.
The results of these additional scenarios came close to, but did not meet the established TMDL thresholds in either
Nantucket or Polpis Harbor. These results show Nantucket that while meeting existing conditions as is now seen with
developed parcels may meet the water quality standards, the Town needs to have a plan in place to adapt to build-
out conditions. While 100 percent build-out may never occur, the Town has the responsibility to monitor the water
quality conditions in the identified embayment/harbor/pond areas through the Annual Water Quality Program and
adapt as needed as is discussed throughout the Adaptive Management Planning process.
The result is a need for Nitrogen management in the overall system in order to restore the resources and limit future
nitrogen loading in the watershed.
In May 2014, an additional three scenarios were modeled utilizing existing conditions. These include:
Town of Nantucket (#225139.00)2-13 Woodard & Curran
Final CWMP Update Report Volume I October 2014
Elevate jetties to ACOE specifications, sewer Town Sewer District with updated parcel data, sewer1.
Monomoy
Elevate jetties to ACOE specifications, sewer Town Sewer District with updated parcel data, sewer2.
Monomoy, include fertilizer reductions as per Town’s BMP
Elevate jetties to ACOE specifications, sewer Town Sewer District with updated parcel data, sewer3.
Monomoy with new delineations as defined in CWMP Update, include fertilizer reductions as per Town’s
BMP
Scenarios 9 through 11 each are sufficient to meet the TMDLs established in both Nantucket and Polpis Harbors.
There was no significant difference between the three scenarios, but the addition of fertilizer reduction based on the
Town’s BMP reduced the overall numbers by a small margin based on the computer model. It is recommended that
the Town monitor these results during and after implementation in the Adaptive Management Plan in order to
add/revise or delete solutions. For example, particular attention needs to be paid to any dredging at the entrance to
Polpis Harbor as this model determined that this would add Nitrogen (N) rather than reduce it due to the physics of
tidal flushing. Dredging will allow a larger volume of water into the Harbor, which maintains a much longer residence
time as there is no mechanism to then flush water out. This results in an increase in N concentrations since the water
has a longer period of time to be exposed to the addition of nitrogen inputs from the watershed and sediments.
It is recommended that the Town apply scenarios 9 through 11, with a mixed approach for the Harbor. Start with the
most impactful approach first-with this being the reconstruction of the east and west jetties to the Army Corps of
Engineers (ACOE) specifications. This project is in final design phase and due for implementation in early 2015
based on the most current project update (July 2014). Careful monitoring of results will be needed to measure the
actual improvements realized from implementation of the jetties reconstruction and to manage the implementation of
other solutions for the Adaptive management Plan. Once the Town understands the improvements realized, it can
adapt and add additional implementation of solutions on an as needed basis. This approach under the Adaptive
Management Plan affords the Town the ability to refine what tasks it takes on in the MEP areas as it better
understands the real, versus computer modeled, results from implementation of solutions as shown in current data.
As the town moves further into the Adaptive Management process, it will better understand the details of each of the
varied MEP areas on Island and what solutions appear to be making the most progress in real world results.
Additional items to follow are the cranberry bogs in the Watershed and Pest House Pond. The bogs utilize N to
fertilize and Pest house Pond has a direct discharge to Nantucket Harbor. We recommend some water sampling in
Mill Brook to determine if any impact to Polpis Harbor is seen from the bogs. Pest House Pond has an open pipe
that discharges directly to the harbor. This needs follow up. All of the Technical Memorandums detailing the model
run scenarios are included in Appendix C.
CWMP Update Adaptive Management Plan to Meet Nantucket Harbor/Polpis Harbor TMDL2.4.3
The Town will continue with its mandate to sewer all areas located within the Town Sewer District where
infrastructure exists under Local Regulation 69.00. The reconstruction of the east and west jetties in Nantucket
Harbor are currently under design with the ACOE and as of last update in July 2014, due to be bid in late fall 2014
with construction starting early 2015. The Town has begun enforcement of its Fertilizer Regulations, which will be an
on-going effort Island-wide, with particular attention paid to the Harbor Watershed areas. As the above approaches
are implemented, data will support the need for additional work, which includes extending the municipal sewer to the
Monomoy Needs Area. Future considerations include extending sewer to Shimmo Needs Area, implementing a Local
Regulation for Innovative/Alternative (I/A) systems within the Study Areas delineated within MEP Areas and potential
future stormwater BMPS based on the Town completing a Stormwater Master Plan. The Town will continue to
monitor water quality in Nantucket and Polpis Harbor through its Annual Water Quality Testing Program. The
historical MEP Sentinel Stations will be sampled on a regular basis in order to monitor results as the Town moves
forward with its plan to meet the TMDLs established in this location.
Figure 2-6
Location of Sentinel Stations in Nantucket Harbor MEP
Town of Nantucket (#225139.00)2-15 Woodard & Curran
Final CWMP Update Report Volume I October 2014
2.4.3.1 Sesachacha Pond MEP
The Final Report titled, “Linked Watershed Embayment Model to Determine Critical Nitrogen Loading Threshold for
Sesachacha Pond, Town of Nantucket, MA” was issued in November 2006. This estuary includes Nantucket Harbor
and Polpis Harbor. The system’s geographic location is on the Island’s eastern shore bounded directly abutting the
Atlantic Ocean to its east. See Figure 2-7 from the MEP (Figure I-1 in MEP) that shows the locale of the study.
The MEP states, “The Sesachacha Pond Embayment is a simple estuary located within the Town of Nantucket on
the Island of Nantucket, Massachusetts. Sesachacha Pond is stabilized as an estuarine system by periodic
management breaching of the barrier beach, which separates the salt pond from the marine waters of the Atlantic
Ocean. The Pond is breached 2-3 times per year to lower its nitrogen levels and raise its salinity through the
exchange of brackish pond waters with the high quality offshore waters. Pond openings are also to allow the entry of
marine larvae and potentially herring. Studies of Sesachacha Pond in the late 1980's indicated that periodic tidal
exchange was required to help stabilize the ecology. Data indicated that not breaching the Pond regularly for
management would result in long term cycling of pond waters between saline and near freshwater (water with less
than 3 parts per thousand of salt is considered freshwater) due to the freshening by groundwater inflow and periodic
storm inflows of salt water (Howes and Goehringer 1989). This salinity cycling would result in highly unstable
conditions and impairment of habitat quality. The natural breaching of the barrier beach was subsequently observed
during Hurricane Bob in 1991. Sesachacha Pond has been breached for management purposes for more than a
century, with greater and lesser success. However, it is clear that the health of this estuary’s habitats is dependent on
the amount and timing of periodic tidal exchanges.”
Sesachacha Pond is approximately 6.0 miles northeast of the Nantucket Town center and its watershed abuts the
watershed to Nantucket Harbor. Sesachacha Pond is situated on the eastern coast of Nantucket Island between
Squam Head and Sankaty Head. The watershed to Sesachacha Pond is fully within the Town of Nantucket. All
watershed freshwater and nutrients enter Sesachacha Pond via groundwater seepage, as there are no significant
surface inflows to this system. As a result, there is little opportunity for nitrogen removal during transport from
watershed source to estuarine waters. The Pond is comprised of a single basin and a narrow barrier beach.
Sesachacha Pond meets Massachusetts Statute as a Great Pond. Refer to Figure 2-8 (Figure III-1 from MEP) for a
map of the watershed.
The MEP Report determined the nitrogen loading contributors are groundwater, which transports wastewater from
septic systems, fertilizer, impervious surfaces, direct atmospheric deposition to water surfaces, and recharge within
natural areas. Based on the land use, the major nitrogen contributors that are locally controllable are impervious
surfaces (stormwater), wastewater and fertilizer as detailed in Figure 2-9 (Figure IV-4 from the MEP). However for
this water body the nitrogen load from wastewater and fertilizer are deemed relatively low due to the low-density
development in this Watershed. Figure 2-10 (Figure VI-1 from the MEP) details the sampling locations in the Pond.
Model Run Scenario2.4.4
The modeling completed in the MEP determined that the best management practice for meeting the threshold water
quality for the Pond is through breaches to the ocean to afford tidal flushing that maintains water quality as well as
appropriate salinity levels. One of the major goals of the Sesachacha Pond MEP evaluation was to determine the
best protocol for Pond openings so that they would support the highest quality habitat within the embayment. The
Town has included Sesachacha in its bi-annual breaching program, along with Hummock Pond on the southern
shore, which has led to maintenance of the water quality thresholds established in the MEP. The Town completed its
third year (2013 Annual Water Quality Testing) with preliminary data showing the openings continue to reach the
water quality thresholds with the ultimate goal of submitting the last three years water quality reports to the state to
remove the Pond from the state’s list of impaired waters. Sesachacha Pond is one of the state’s first success stories
within the overall MEP Project.
Town of Nantucket (#225139.00)2-16 Woodard & Curran
Final CWMP Update Report Volume I October 2014
CWMP UPDATE FINAL ADAPTIVE MANAGEMENT PLAN TO MEET SESACHACHA POND THRESHOLD
ESTABLISHED IN MEP (NO Formal TMDL, BUT THRESHOLD LEVELS ESTABLISHED AND DOCUMENTED)
The Town will continue to breach Sesachacha Pond twice annually in April and October. Sesachacha Pond Sentinel
Station will be included in the Town’s Annual Water Quality Testing program to continue to monitor results. The
Town’s 2013 Annual Water Quality Monitoring Program will support previous results in order to petition the state to
remove Sesachacha Pond from the State’s List of Impaired Waters.. At the time of this Report, the Sesachacha
Pond Report had not been received from SMAST.
Figure 2-7
Map of Sesechacha Pond MEP
Figure 2-8
Sesechacha Pond MEP Watershed
Figure 2-9
Sesechacha Pond Nitrogen Load
MASSACHUSETTS ESTUARIES PROJECT
Figure 2-10
Location of Sentinel Stations in
Nantucket Harbor MEP
Figure VI-1. 2005 aerial photo showing monitoring station location in Sesachacha Pond that was used in
the water quality analysis.
Town of Nantucket (#225139.00)2-21 Woodard & Curran
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2.4.4.1 Madaket Harbor and Long Pond MEP
The Report titled, “Linked Watershed Embayment Model to Determine Critical Nitrogen Loading Threshold for the
Madaket Harbor and Long Pond Estuarine System, Town of Nantucket, MA” was issued in June 2010. This estuary
includes Madaket Harbor, Hither Creek and Long Pond. The system’s geographic location is on the far western edge
of the Island with Madaket Harbor generally open to Nantucket Sound and the Atlantic Ocean restricted in some
areas by a complex group of land shoals. Hither Creek is connected in land to Madaket Harbor on the east and Long
Pond through Madaket Ditch to the west. See Figure 2-11 (Figure I-2 from the MEP) that shows the locale of the
study.
The Madaket Harbor and Long Pond MEP Report summarizes the study results’ as stating that Madaket Harbor area
itself appears to be below the nitrogen threshold and therefore supporting healthy aquatic habitat. This is an area
wide open to Nantucket Sound and the Atlantic Ocean, which affords a large tidal flushing of the area thus
maintaining healthy water quality in the water. In contrast to Madaket Harbor, Long Pond and Hither Creek are well
beyond their respective abilities to assimilate additional nutrient loading without impacting ecological health. Nitrogen
levels are elevated in these areas with eelgrass beds totally lost from Hither Creek. The result is a need for nitrogen
management in the overall system in order to restore the resources and limit future nitrogen loading in the watershed.
See Figure 2-12 (Figure III-1 from MEP) that breaks the system down into the sub-watersheds.
On Figure 2-13 (Figure IV-6 from MEP), the MEP report details the land-use specific nitrogen load to the overall
Madaket Harbor System Watershed, with wastewater being the major locally-controllable source. The major Nitrogen
loads are attributed to the landfill and on-site wastewater systems. The MEP evaluated a model scenario of removing
all wastewater from the Hither Creek watershed, which met the threshold established. The landfill is included as an
overall contributor at 10 percent and as a locally controllable contributor at 21 percent. The MEP report suggests that
the current mining of the landfill results in a reduction of nitrogen loading in this area. The landfill is a “piece” of the
locally controllable portion of nitrogen loading and is a part of the overall solution to meeting the draft TMDL that
MassDEP issued in August 2011. Figure 2-14 (Figure VI-1 from MEP) details the sampling locations in this Estuary
System.
With the current mining operation of the landfill, material in the existing unlined cell is removed, sorted, portions
passed through a digester and/or recycled. Some materials that cannot be recycled are then shipped off Island and
what cannot be recycled or reused are then placed in lined cells, which are then capped preventing contamination to
the groundwater. This process reduces the potential for nitrogen loading to the groundwater that ultimately flows into
the watershed via Long Pond, Madaket Ditch, Hither Creek and ultimately Madaket Harbor. As this process
continues, nitrogen loading is further reduced to the overall watershed. The Town’s 2012 Annual Water Quality
testing shows preliminary results that this mining is reducing the Nitrogen load to Long Pond and together with the
removal of on-site wastewater is the solution to meet the TMDL in this embayment area. See Section 2.8 for more
detailed information on the landfill mining.
CWMP UPDATE FINAL ADAPTIVE MANAGEMENT PLAN TO MEET MADAKET HARBOR / LONG POND
THRESHOLD ESTABLISHED IN MEP ( Draft TMDL issued)
The Town will continue to mine the landfill and monitor water quality testing done in this location for further reductions
of N. Madaket and Warren’s Landing Needs Areas are proposed for municipal sewering at the Surfside WWTF thus
removing 100 percent of the land use wastewater contributing to the degradation, which based on the MEP , will
serve to meet the Draft TMDL issued for this area.
The Draft TMDL issued by the Massachusetts Department of Environmental Protection is detailed in the following
Section 2.5 along with the final nutrient management plan for this geographical area. A copy of the TMDL can be
accessed in Appendix C.
MASSACHUSETTS ESTUARIES PROJECT 3N. Head Long PondNantucket SoundAtlantic OceanMadaket HarborLong PondHither CreekMadaket DitchEel PointN. Head Long PondNantucket SoundAtlantic OceanMadaket HarborLong PondHither CreekMadaket DitchEel Point Figure I-2. Major component basins of the Madaket Harbor Estuary system as assessed by the Massachusetts Estuaries Project. Freshwaters enter from the watershed primarily through direct groundwater discharge to Long Pond and Hither Creek as well as to the Harbor proper. Surfacewater from Long Pond also flow to Madaket Harbor via Madaket Ditch and Hither Creek.
FIGURE 2-12
Map of Madaket Harbor and Long Pond MEP Sub-Watersheds
FIGURE 2-13
Madaket Harbor and Long Pond MEP Nitrogen Load
Figure 2-14
Location of Sentinel Stations in Madaket Harbor
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Final CWMP Update Report Volume I October 2014
2.4.4.2 Hummock Pond MEP
The Draft Report titled, “Linked Watershed Embayment Model to Determine Critical Nitrogen Loading Threshold for
the Hummock Pond Estuarine System, Town of Nantucket, MA” was issued in January 2014. This estuary includes
the main body of Hummock Pond, as well as the Head of Hummock Pond. The system’s geographic location is on
the southern shore abutting Nantucket Sound and the Atlantic Ocean. As the MEP Report states, the Hummock
Pond Embayment system is a simple coastal pond estuary with a single temporary inlet, a main estuarine basin in
the lower part of the system and a narrow upper section that connects to a small basin that is known as Head of
Hummock. See Figure 2-15 from the MEP (Figure I-2 in MEP) that shows the locale of the study.
The Hummock Pond MEP Report summarizes the study results’ as stating that Hummock Pond is presently
supporting a gradient in impairment from significantly impaired in the upper basin to moderately impaired in the
lowest portion adjacent to the barrier beach. The area that is showing severe impairment is the basin of Head of
Hummock. Head of Hummock contains less salinity than the main portions of the Pond due to its location in the
upper most region and functions more as a kettle pond as it does not receive any mixing from tidal currents. The
Head of Hummock is not supporting any significant habitat. The Report delineated the current Watershed, which was
revised a bit since the 1990 Horsley Whitten Study delineated the Town’s watersheds due to the fact that Clark’s
Cove is no longer attached to the Hummock Pond watershed. Refer to Figure 2-16 (Figure III-1 from MEP). The MEP
utilized the Town of Nantucket’s Island-wide water Quality Monitoring Program sampling stations to conduct this
study so new results of testing correspond to historic records. See Figure 2-17 (Figure II-1b from MEP) for a location
of the stations. The ensuing result is a need for nitrogen management in the overall system in order to restore the
resources and limit future nitrogen loading in the watershed. Based on the nature of the Pond with almost a separate
upper Head of Hummock and the main basin, the nitrogen management recommended is individual in nature to
support each section.
The MEP report identifies the land-use specific nitrogen load to the overall Hummock Pond Watershed, with
wastewater being the major locally controllable source at 81 percent contribution. See Figure 2-18 (Figure IV-3 from
MEP). The major locally controllable nitrogen load is attributed to the on-site wastewater systems. There are a
number of smaller contributors such as impervious surfaces at 7 percent, farm animals at 6 percent and fertilizer at 4
percent. While these rates are small, they are “pieces” of the puzzle that the Town can address in the proposed
Adaptive Management Plan to help with the overall solution. For example, although fertilizer is contributing only 4
percent, the Town has a fertilizer regulation in place and when it is fully implemented, will help towards reducing any
current and surely future potential for degradation to continue from this source. The same holds true for stormwater.
This CWMP Update recommends that the Town complete a Stormwater Master Plan to address runoff issues, as
well as a host of other issues in the overall wastewater system.
The MEP evaluated a model scenario of removing all wastewater from the watershed, which did not meet the
threshold established based on results from Station 3 testing. The following are the MEP report recommendations for
the entire Hummock Pond watershed:
2.4.4.2.1 Head of Hummock
With Head of Hummock evaluated as a separate unit, the Adaptive Management Plan is to isolate this portion of the
Pond from the main Pond thus allowing it to return to a freshwater kettle pond. Historically, this was a separate
freshwater body that was artificially connected to the main Pond. By cutting it off from the main Pond, there will be a
reduction of nitrogen to the main Pond from this severely impaired water body by 50 percent. As groundwater will
continue to flow hydrogeologically through the system, some nitrogen will continue to be fed to the main Pond, but
the solution below for the main Pond will help alleviate the potential impact. Once returned to freshwater, the Head of
Hummock will become phosphorous limited and more responsive to removals of said nutrient as means of controlling
the observed eutrophication in that receiving water body. There are specific biogeochemical methods that have been
successfully implemented in phosphorous limited impaired ponds (alum, iron, aeration, etc.) and these methods can
Town of Nantucket (#225139.00)2-27 Woodard & Curran
Final CWMP Update Report Volume I October 2014
be used to “treat” the water within the Head of Hummock. Converting the Head of Hummock into a strictly freshwater
pond enhances its function as a natural attenuator of nitrogen. With the recommendation to sewer the Watershed
(see below), the nitrogen load flowing into the Head of Hummock will be eliminated through natural denitrification
processes and prevented from entering the top portion of the main body of Hummock Pond. The amount of load that
passes to Hummock Pond is controlled by the attenuating capacity of the modified fresh water basin. Based on TN
(Total Nitrogen) attenuation observed in freshwater ponds with similar depths and retention times throughout the
southeastern Massachusetts region, it is estimated that Head of Hummock would be able to attenuate 50% of the TN
load entering the pond from its watershed. At present, Head of Hummock as a brackish water basin transforms
significant amounts of nitrogen but ultimately passes nitrogen to the down gradient main basin. Inflowing nitrogen
from the watershed will thereby be limited to those loads associated to the groundwater resources feeding into the
top, middle and lower portions of the main body of the Pond.
2.4.4.2.2 Main Hummock Pond
With wastewater as the largest contributor, it makes sense that this Report recommends reducing the wastewater
that drains to the Pond from the watershed. The main goal of this proposed management scenario (wastewater
related nitrogen load reduction) is to prevent time averaged pond-wide TN concentrations in the pond from rising
above 0.50 mg/L in the main basin of the Pond at a sentinel station (monitoring station HUM-3) during the summer
months, when benthic regeneration and algae production is greatest. A way to achieve these goals is to reduce the
watershed loading to the pond, together with an additional mid-summer breach (export nitrogen). Watershed loading
was reduced from present conditions until the time averaged TN concentration at sentinel station HUM-3 would
remain below 0.50 mg/L during a complete breaching cycle, where the pond is open to tidal flushing for at least four
days and subsequently closed for 60 days. An 81 percent reduction in wastewater is needed, but this alone will not
lower water column nitrogen levels to meet the threshold set. In addition to sewering the watershed, the additional
breach is also recommended. Historically, the bi-annual breaches have not been engineered to afford a tidal wash
into the Pond but instead just to drain the Pond. The Report details the need to model a breach that will afford a tidal
wash of at least four (4) days and then subsequently closed for at least 60 days.
This Report recommends that the Town work to forecast breach weather conditions well in advance of any openings
in order to meet the above needed conditions. The Town applied this science to its regularly scheduled breach in
April. Tides were forecast according to the moon schedule, winds were forecast and in addition, the actual opening
cut was engineered to afford an opening that would not only drain the Pond, but also afford the open ocean water to
flush up into the Pond, which flushes old water pout and replaces with new, fresh ocean water. The date that
matched all of the above was April 16, 2014 and the plan was put in to place. The actual breach was a success in
that the opening was maintained for over seven days-longer than the recommended four from the MEP report. Water
sampling was done before the opening and after to compare results, especially salinity. Initial results of this testing
showed that salinity levels rose throughout the Pond and Total Nitrogen was lowered. SMAST will synthesize the
water level data along with salinity and nutrient data for the April 2014 opening and the October 2014 opening and
pull it all together in a separate memorandum, which will come after this Report.
A Draft TMDL has not yet been issued by the Massachusetts Department of Environmental Protection, but should be
at some future point based on the results of this MEP. The Town, being proactive, is detailing solutions to meet the
water quality standards set for this Watershed in this CWMP Update. Once a TMDL is issued, the Town will be well
on its way to meeting the mandate.
FIGURE 2-15
HUMMOCK POND MEP
FIGURE 2-16
HUMMOCK POND MEP WATERSHED
FIGURE 2-17
HUMMOCK POND MEP SAMPLING STATIONS
FIGURE 2-18
HUMMOCK POND NITROGEN CONTRIBUTIONS
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Final CWMP Update Report Volume I October 2014
CWMP UPDATE FINAL ADAPTIVE MANAGEMENT PLAN TO MEET HUMMOCK POND THRESHOLD
ESTABLISHED IN MEP (No Formal, issued TMDL to date. The following recommendation is based on the
results detailed in the Report, which will form the future basis for a TMDL)
The Town has identified Hummock Pond South and Hummock Pond North as Needs Areas requiring an off-site
wastewater solution. The Adaptive Management Plan contained herein proposes to collect, transport and treat these
Needs Areas at the existing Surfside WWTF, thus removing the 81 percent wastewater from land use in the
Watershed. In addition, the Town will work towards more finite planning for semi-annual breaches of Hummock Pond
by forecasting weather conditions looking towards conditions that present the appropriate weather conditions, tides
and northerly winds to afford an opening that stays open to tidal flushing for a minimum of four days. Hummock Pond
Sentinel Station 3 will be included in the Town’s Annual Water Quality Testing program to continue to monitor results.
Another piece to this Plan is the separating of the Head of Hummock from the main Pond as was detailed earlier in
this Report. This Plan is currently being evaluated through the Nantucket Land Council together with the Town.
2.5 TOTAL MAXIMUM DAILY LOADS AND WATER QUALITY IMPAIRMENTS
One of the major drivers for the Town to update its 2004 CWMP is due to the Massachusetts Estuaries Program
(MEP) Reports that were completed after the 2004 CWMP was filed and approved. The MEPA Certificate issued on
the 2004 CWMP reiterated the fact that once the MEP studies were completed, the CWMP would need to be updated
and the TMDLs issued addressed. This CWMP Update serves as the update mandated in 2004. While the 2004
CWMP detailed the on-going studies, it took another almost ten years for the MEP Reports to be completed and
some TMDLs finalized, some in draft form and Hummock Pond yet to be issued. Since that time, MEP Reports for
the following waterbodies were completed:
Nantucket Harbor;
Polpis Harbor;
Sesachacha Pond*
Madaket Harbor / Long Pond
Hummock Pond.
As a result of the above, TMDLs for the following waterbodies have been issued:
Nantucket Harbor;
Polpis Harbor;
Madaket Harbor / Long Pond (draft)
Hummock Pond (pending)
*Note There was no official TMDL issued for Sesachacha Pond based on the 2006 study; it is listed on the State’s
List of Impaired Waters as needing a TMDL. While no formal TMDL document was issued, thresholds were
established and documented in the MEP and are on record with MassDEP. As a result of the MEP, the Report
recommended water quality thresholds that are being monitored through two breaches happening bi-annually in April
and October. Now in the third year of Annual Water Quality Testing through SMAST, Sesachacha Pond results are
meeting thresholds established in the 2006 MEP and the Pond is on its way to be eliminated from the State’s List of
Impaired Waters.
Since preparation of the 2004 CWMP/FEIR, there have been changes to the water quality impairments and Total
Maximum Daily Loads (TMDLs) that apply to waterbodies within Nantucket. The Massachusetts Integrated List of
Waters (the Final Massachusetts Year 2010 Integrated List of Waters was approved by EPA on November 16, 2011
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Final CWMP Update Report Volume I October 2014
and the Proposed Massachusetts Year 2012 Integrated List of Waters was released in January 2012) and the
Surface Water Quality Standards have been updated, and three TMDLs have been released as drafts or final
TMDLs.
The objective of the Federal Clean Water Act (CWA) is to restore and maintain the chemical, physical, and biological
integrity of the Nation’s waters. As a step to reach this goal, under Section 305(b) of the CWA, MassDEP is tasked
with monitoring and assessing the quality of waters of Massachusetts, evaluating if water bodies can support
designated uses. Designated uses include aquatic life support, fish and shellfish consumption, drinking water supply,
and primary (e.g., swimming) and secondary (e.g., boating) contact-recreation as identified in the State Surface
Water Quality Standards (314 CMR 4.00). Under Section 303(d) of the CWA, the State is required to identify those
waterbodies that are Impaired (not expected to meet surface water quality standards and designated uses after the
implementation of technology-based controls) and develop a plan and schedule to bring the impaired waters back
into compliance with the water quality standards through a TMDL. The Integrated List of Waters identifies specific
segments of each water body based on the following categories:
Category 1 Waters – “Waters attaining all designated uses”
Category 2 Waters – “Attaining some uses; other uses not assessed”
Category 3 Waters – “No uses assessed”
Category 4a Waters – “TMDL is completed”
Category 4b Waters – “Impairment controlled by alternative pollution control requirements”
Category 4c Waters – “Impairment not caused by a pollutant”
Category 5 Waters – “Waters requiring a TMDL”
Water bodies identified as Category 5 waters on the Integrated List are equivalent to the “303(d) list” of water quality
impaired waters under the Clean Water Act.
Once a body of water is identified as a Category 5 water body on the Integrated List of Waters, MassDEP is required
by the CWA to develop a “pollution budget” designed to restore the health of the impaired body of water. The process
of developing this budget, generally referred to as a Total Maximum Daily Load (TMDL), includes identifying the
source(s) of the pollutant from direct discharges (point sources) and indirect discharges (non-point sources),
determining the maximum amount of the pollutant that can be discharged to a specific water body to meet water
quality standards, and assigning pollutant load allocations to the sources.
As a result of the MEP Reports, three formal TMDLs have been issued to Nantucket waters, with Sesachacha Pond
listed as needing a TMDL and a fifth potential expected as a result of the completion of the Hummock Pond MEP.
Final Nantucket Harbor Embayment System TMDL for Total Nitrogen2.5.1
The Nantucket Harbor Embayment System TMDL for Total Nitrogen (Report # MA97-TMDL-2, Control #249.0) was
issued on January 28, 2009 and approved by EPA on May 12, 2009. The TMDL was issued due to excessive
Nitrogen loading from a variety of sources that led to degradation to the environmental quality in the overall
Nantucket Harbor system that includes Polpis Harbor. In order to restore the system, and preserve and protect it in
the future, the concentrations of Nitrogen must be reduced to levels that are below the thresholds detailed in the MEP
Report. The MEP Report determined that N concentrations of 0.35 mg/L in Head of the Harbor (Sentinel Station 2A)
and an N concentration of 0.36 mg/L in Polpis Harbor (Sentinel Station 4) will meet the target thresholds. See Figure
2-6 in previous section for Sentinel Station location.
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Final CWMP Update Report Volume I October 2014
The major goal of the TMDL is for the Town to implement a plan that reduces N loading from the sources identified in
the MEP as the contributing factors. In Nantucket Harbor’s case, there are a multitude of locally controllable
contributors including wastewater, fertilizer and stormwater and the percentages of these differ in Nantucket Harbor
and Polpis Harbor. A major consideration in putting together a plan to meet the established thresholds is to include
future build out scenarios. If the Town only planned for existing conditions to meet existing established thresholds,
additional loading from future build out can exacerbate the environment and eliminate any good the original plan
intended. On a proactive level, build out is included in this CWMP Update to provide for future conditions.
Table 2-3 details the present N load and target threshold, with the final column showing the percentage of reduction
needed to achieve the threshold.
Table 2-3: Nantucket Harbor Estuary N Reductions Necessary to Meet TMDL (Table 4 from MEP)
The critical element in achieving the above reductions is developing and implementing a plan that meets the targets
set at the two sentinel Stations in the Harbor – 2A (Nantucket Harbor) and 4 (Polpis Harbor). The results of the model
scenarios completed for this embayment area detail the following plan to meet the above:
Elevate jetties to ACOE specifications, sewer Town Sewer District with updated parcel data, sewer
Monomoy
Elevate jetties to ACOE specifications, sewer Town Sewer District with updated parcel data, sewer
Monomoy, include fertilizer reductions as per Town’s BMP
Elevate jetties to ACOE specifications, sewer Town Sewer District with updated parcel data, sewer
Monomoy with new delineations as defined in CWMP Update, include fertilizer reductions as per Town’s
BMP
The above scenarios each are sufficient to meet the TMDLs established in both Nantucket and Polpis Harbors. There
was no significant difference between the three scenarios, but the addition of fertilizer reduction based on the Town’s
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BMP reduced the overall numbers by a small margin based on the computer model. It is recommended that the Town
monitor these results during and after implementation in the Adaptive Management Plan in order to add/revise or
delete solutions. It is recommended that the Town apply these scenarios, with a mixed approach, implementing the
most impactful approach first-with this being the reconstruction of the east and west jetties to the ACOE
specifications. This project is in final design phase and due for completion in early 2015. With the Adaptive
Management Planning approach and in order to provide sufficient reductions in TN concentrations, careful monitoring
of results will be needed to measure the actual improvements realized from implementation of the jetties
reconstruction. Once the Town understands the improvements realized, it can adapt and add or reduce additional
implementation of solutions on an as needed basis. This approach, under the Adaptive Management Plan, affords
the Town the ability to refine what tasks it takes on in the MEP areas as it better understands the real, versus
computer modeled, results from implementation of solutions as shown in current data. As the Town moves further
into the Adaptive Management process, it will better understand the details of each of the varied MEP areas on
Island and what solutions appear to be making the most progress in real world results.
In addition, it is recommended, the Town fully implements the approved Septage Management Plan to include a
septic tank pump out program. It is also suggested, that the town closely monitor build-out in the Needs Areas with
the potential to implement a new Local Regulation requiring all new properties developed within the delineated Needs
Areas be built utilizing an Innovative/Alternative system that reduces TN load to the groundwater. These I/A systems
attain a 50 percent TN reduction over conventional Title 5 systems and in areas where no sewer infrastructure is
planned will serve to supplement all efforts at reducing TN loading. This is critical when looking at build-out conditions
based on current land uses. If the Town sets an Adaptive Management Plan in place under existing conditions, which
attains the thresholds set by the MEP, it must also take future loading from build out into consideration.
All final plans put in place will be monitored closely in the Town’s Annual Water Quality Program, which is currently
an on-going event. The schedule and locations of the current tracking are coordinated directly to the MEP reports
and subsequent TMDLS in order to show progress at sentinel Stations and throughout the watershed. It is
recommended that this process continue to monitor TMDL compliance.
Draft Madaket and Long Pond Estuarine System TMDL for Total Nitrogen2.5.2
The Draft Madaket and Long Pond Estuarine System TMDLs for Total Nitrogen (Report # 97-TMDL-5 Control #
283.0), was released in August 2011. This TMDL applies to impaired waterbodies on the Category 5 list, including
Hither Creek, Long Pond, and Madaket Harbor.
The TMDL was issued due to excessive Nitrogen loading from a variety of sources that led to degradation to the
environmental quality in the overall Madaket Harbor system that includes Hither Creek and Long Pond. In order to
restore the system and preserve and protect it in the future, the concentrations of Nitrogen must be reduced to levels
that are below the thresholds detailed in the MEP Report. The MEP Report determined that N concentrations of 0.45
mg/L in Hither Creek (Sentinel Station M11) will meet the target thresholds range from 1.67 kg/day in the Hither
Creek subwatershed to 27.218 kg/day in the Madaket Harbor watershed. Refer to Figure 2-14- in the previous
section for location of Sentinel Stations.
The major goal of the TMDL is for the Town to implement a plan that reduces N loading from the sources identified in
the MEP as the contributing factors. In Madaket Harbor’s case, the major source of degradation is wastewater.
2.5.2.1 Model Run Scenario
The TMDL model run scenario recommends removing 100 percent of the septic load for the watershed while
continuing to mine and reduce the nutrient loading impacts from the landfill. A major consideration in putting together
a plan to meet the established thresholds is to include future build out scenarios. If the Town only planned for existing
conditions to meet existing established thresholds, additional loading from future build out can exacerbate the
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environment and eliminate any good the original plan intended. On a proactive level, build out is included in this
CWMP update to provide for future conditions.
Table 2-4 (Table 6 from the TMDL) details the present N load and target threshold, with the final column showing the
percentage of reduction needed to achieve the threshold.
Table 2-4: Madaket Harbor Estuary N Reductions Necessary to Meet TMDL (Table 6 from MEP)
Table 6: Present Watershed Nitrogen Loading Rates, Calculated Loading Rates that are Necessary to Achieve
Target Threshold Nitrogen Concentrations, and the Percent Reductions of the Existing Loads Necessary to Achieve
the Target Threshold Loadings
Sub-embayment System
Present Total
Watershed
Load 1
(kg/day)
Target
Threshold
Watershed
Load2
(kg/day)
Percent
Watershed Load
Reductions
Needed to Achieve
Target
Madaket Harbor 0.663 0.663 0%
Hither Creek 4.041 1.134 71.9%
Madaket Ditch 2.433 2.433 0%
North Head Long Pond 0.238 0.238 0%
Long Pond 3.230 1.101 65.9%
Total for Madaket Harbor/ Long Pond
Estuarine System 10.605 5.570 47.5%
1 Composed of septic, fertilizer, landfill and runoff loadings.
2 Target threshold watershed load is the N load from the watershed (including natural background) needed to meet
the target threshold N concentrations identified in Table 4, above.
Taken from Tables ES-2 and VIII-3 in the MEP Technical Report
The critical element in achieving the above reductions is developing and implementing a plan that meets the targets
set at the Sentinel Station, M11 for the overall Madaket Harbor System. The results of the model scenario completed
for this embayment area are to sewer 100 percent of the Watershed, which is included in the Final Recommended
Plan for both the 2004 and this CWMP Update based on additional criteria. Both Madaket and Warren’s Landing
Needs Areas (two geographical areas in the overall watershed) are identified as Needs Areas-areas needing off-site
wastewater solutions. Initially both of these Needs Areas were determined to need an off-site wastewater solution
based on criteria developed in the 2004 CWMP, which did not include nutrient loading, as this was not as issue when
the original CWMP was begun. We now take the original criteria and add the nutrient factor to it and it strengthens
the need for off-site wastewater. The Final recommended Plan is to sewer this area with low-pressure infrastructure
and send the wastewater to the Town’s main treatment facility, Surfside WWTF for treatment and disposal. The
Town’s existing Groundwater Discharge Permit at Surfside has been approved by MassDEP to be modified from 3.5
MGD (existing) to 4.0 MGD to accept this geographical area rather than the Town designing and constructing a third
WWTF in Madaket.
In addition, it is recommended that the Town closely monitor its water quality testing in Long Pond adjacent to the
landfill, to determine the overall impact mining the landfill has on the water resources with respect to Nitrogen
reduction. To date, testing between 2010 and 2012 is showing results of N reduction of over 40 percent in this area.
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Sesachacha Pond2.5.3
Sesachacha Pond (Segment ID MA97-02 was not issued a formal TMDL document as a result of the 2006 MEP
Report, but did establish and document water quality threshold statistics. The MEP Report determined the Nitrogen
loading, as determined through groundwater, as wastewater (e.g., septic systems), fertilizer, impervious surfaces,
direct atmospheric deposition to water surfaces, and recharge within natural areas. Basically, Nitrogen load from
wastewater and fertilizer are deemed relatively low due to the low-density development in this Watershed. Based on
the land use, the major Nitrogen contributors that are locally controllable are impervious surfaces (stormwater),
wastewater, and fertilizer. Because of the lack of housing/development densities in the watershed, these contributors
are low.
The modeling completed in the MEP determined that the best management practice for meeting the threshold water
quality for the Pond was through breaches to the ocean to afford tidal flushing that maintains water quality as well as
appropriate salinity levels. One of the major goals of the Sesachacha Pond MEP evaluation was to determine the
best protocol for Pond openings so that they would support the highest quality habitat within the embayment. The
Town has included Sesachacha in its bi-annual breaching program, along with Hummock Pond on the southern
shore, which has led to maintenance of the water quality thresholds established in the MEP.
The Final Recommended Adaptive Management Plan to meet the thresholds in this area is to continue with the bi-
annual breaching of the Pond in April and October. The Town is in its third year (2013 Annual Water Quality Testing)
with preliminary data showing the openings continue to reach the water quality thresholds with the ultimate goal of
submitting the last three years water quality reports to the state to remove the Pond from the state’s list of impaired
waters. Sesachacha Pond is one of the state’s first success stories within the overall MEP Project.
Hummock Pond2.5.4
The Hummock Pond MEP was completed in January 2014. At the time of this Report writing, no official TMDL has
been issued. The Report contains the water quality thresholds necessary to meet water quality standards for the
Pond and this data is the data utilized in the future to issue a TMDL.
The Model Run Scenarios completed for the Hummock Pond MEP met the water quality threshold set at Station 3 in
the main Pond. The models completed include removing the land use wastewater from the Watershed, which in itself
did not meet the threshold. In addition to sewering, the model run for breaching the Pond semi-annually and possibly
a third breach during the time when the population is at its highest, thus the highest N loading time. The sewering
and breaching together meets the threshold. The Final Recommended Adaptive Management Plan for this area is to
forecast and plan breaching to meet tides, winds, weather, and specifications for depth and width in order to get a
sustained breach for at least four days that will afford a sufficient tidal flush versus draining the Pond. In addition, the
removal of the Head of Hummock from the main Pond is recommended to reduce N loading. Consequently,
Hummock Pond North and Hummock Pond South have been added to the CWMP Update Needs Areas and
recommended for sewering.
2.6 STORMWATER UPDATE
According to the Town’s GIS mapping, the stormwater collection system consists of approximately 20 miles of storm
drain pipes, and over 3,000 structures including catch basins, drainage manholes, infiltrators, grit chambers, and
outfalls. The majority of the drainage system serves the downtown area and discharges directly into Nantucket
Harbor. Some of the outfalls discharge to wetland areas. In some cases, the outfalls that drain to the Harbor are
inadequately sized and impacted by backwater from the ocean tides, which results in upstream system surcharging,
sediment deposition, and surface flooding.
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The Town’s stormwater systems were detailed in the July 2006 Sewer System Evaluation Study. This Report
recommended a series of improvements that would eliminate surge charging, street flooding, and undersized piping
and deteriorated structural integrity of the pipes. The plan was delineated into three phases, with Phase I and Phase
II completed as of the writing of this Report. These areas include Children’s Beach, Orange Street, and Consue
Springs. The 2004 CWMP carried approximately $24,000,000 worth of stormwater improvements in the three phases
consisting of both outfall and infrastructure improvements, with approximately $9,000,000 completed to date.
Previous reports detail a balance of approximately $15,000,000 with an inflation factor of 3 percent per year resulting
in a 2014 cost of $20,000,000 in improvements. Because a significant amount of time has passed since these
recommendations, as well as the completion of the Town’s MEP studies, it is the recommendation of this Update that
the Town complete a Stormwater Master Plan. This study will identify and review not only previous recommendations
for implementation, but also all current work necessary to meet established TMDLs on Island. This CWMP Update
will carry the $350,000 cost for the Stormwater Master Plan in the CIP, but will not carry any previously
recommended amounts until thoroughly reviewed and confirmed.
As part of this CWMP Update, with a goal to address requirements of the Final TMDLs for Total Nitrogen in the
Nantucket Harbor Embayment System, Woodard & Curran evaluated opportunities to reduce nitrogen loads from
stormwater runoff on impervious cover throughout the Nantucket Harbor and Polpis Harbor Watersheds. As part of
this process, W&C reviewed the TMDLs and modeling conducted by the Massachusetts Estuaries Project, the
loading values used to calculate the TMDLs, the Town’s drainage system mapping, and the January 2005 Drainage
Outfall Evaluation prepared by Earth Tech, Inc. and conducted a site walk throughout the four sub-watersheds in
June 2013.
In January 2005, the Town received a Drainage Outfall Evaluation report prepared by Earth Tech, Inc. The report
presented a hydrologic analysis of each outfall’s watershed, capacity evaluation, and conceptual designs to
rehabilitate or replace stormwater outfalls that are either deteriorated or undersized, with consideration for applicable
BMPs to be considered for water quality improvements to the Harbor. This Report recommended improvements to
improve water quality in the harbor by decreasing sediment loading, reduce flooding due to undersized pipes, and
address deficiencies within the drainage system.
Evaluation2.6.1
Woodard & Curran identified and evaluated structural and non-structural stormwater control practices that have the
potential to reduce nitrogen pollution in the Nantucket Harbor Embayment. Structural Stormwater control practices
are systems designed and engineered for the physical removal of total nitrogen from impervious area runoff, such as
bioretention areas/rain gardens, wet ponds, swales, detention basins, filtration units, etc. Non-structural management
systems are operations and conservation practices such as street sweeping, catch basin cleaning, leaf litter cleanup,
rooftop disconnection programs, etc. In addition, Woodard & Curran assessed management of impervious cover both
on private and public parcels (including street right of ways) and structural stormwater treatment retrofits for the
“downtown” area that build upon Earth Tech’s recommendations from their January 2005 Drainage Outfall Evaluation
Report. Watershed boundaries, miles of paved Town/state-owned streets, rooftops, impervious area, and number of
catch basins, were quantified using the Town’s GIS system.
2.6.1.1 Street Sweeping
The following Table 2-5 shows paved roads that are Town or State-owned within the sub-watershed, potential
nitrogen load reductions in kg/day, the load reduction needed per the TMDL and the percentage of load reduction
accomplished as a function of the activity.
Table 2-5: Potential Street Sweeping Load Reduction
Watershed Paved Town/State-
Owned Road Area
Load Reduction -
Street Sweeping 1
Total Load Reduction
Target (kg/day) from % of Target Load
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Final CWMP Update Report Volume I October 2014
(sq. ft.)(kg/day)all sources per TMDL Reduction
Town Harbor 3,624,382 0.113 1.51 7.48%
Quaise 152,856 0.005 0.98 0.51%
Polpis 501,480 0.015 1.34 1.12%
Head of Harbor 284,171 0.009 1.07 0.84%
Total 4,562,889 0.142 4.9 2.90%
1 Monthly sweeping via high efficiency regenerative air-vacuum (8%), factor per EPA Region 1 Stormwater General Permits.
2.6.1.2 Catch Basin Cleaning
Because there are very few-paved town/state owned streets outside of the Town Harbor watershed with non-
infiltrating catch basins and connected drainage systems, only the Town Harbor watershed was evaluated for catch
basin cleaning pollutant reductions. For these estimates, we assumed that all impervious surfaces within the Town
Harbor watershed drain to the catch basins and therefore the total load of nitrogen from these surfaces were
evaluated for pollutant load reductions associated with catch basin cleaning. Rooftop and surface impervious areas
have a different pollutant load export coefficient in the TMDL, and therefore they have been segregated to estimate
catch basin cleaning load reductions.
The following Table 2-6 summarizes impervious surfaces within the Town sub-watershed, potential nitrogen load
reductions in kg/day, the load reduction needed per the TMDL and the percentage of load reduction accomplished as
a function of the activity.
Table 2-6: Potential Catch Basin Cleaning Load Reduction
Watershed
Rooftop
Impervious Area
(sq. ft.)
Surface
Impervious Area
(sq. ft.)
Load
Reduction –
Catch Basin
Cleaning1
(kg/day)
Total Load
Reduction Target
(kg/day) from all
sources per
TMDL
% of Target Load
Reduction
Town Harbor
(Downtown Area)
5,585,374 13,164,981 0.124 1.51 8.20%
1 Semi-annual catch basin cleaning via clam shell truck (2%), factor per EPA Region 1 Stormwater General Permits.
2.6.1.3 Structural Controls
In addition to sweeping and catch basin cleaning, selected catchments were evaluated for nutrient load reductions
based on stormwater control practices in place where possible and based on W&C site visits. Reductions for control
practices are based on assumptions about impervious area managed (e.g. rooftop or surface impervious area) and
the type of stormwater control system (in-place or projected). The following Table 2-7 details drainage areas
identified in Earth Tech’s January 2005 Drainage Outfall Evaluation report that were further evaluated by Woodard &
Curran for potential load reduction through a structural control:
Children’s Beach (034)
The Creek (061)
Consue Spring (127)
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Cambridge Street (074)
Commercial Wharf (116)
Marine Fisheries (148)
Washington Street Extension, Middle and North (159, 187, 197).
Table 2-7: Stormwater Control Structure Load Reduction
Sub-catchment
Rooftop
Impervious Area
(sq. ft.)
Surface
Impervious Area
(sq. ft.)
Load
Reduction
(kg/day) –
Stormwater
Control
System1
Total Load
Reduction Target
(kg/day) from all
sources per
TMDL
% of Target Load
Reduction
Children’s Beach
(034)306,532 369,147 0.036 1.51 2.42%
The Creek (061)49,372 289,071 0.022 1.51 1.45%
Consue Spring
(127)609,595 853,621 0.081 1.51 5.36%
Cambridge Street
(074)218,121 234,084 0.024 1.51 1.59%
Commercial Wharf
(116)74,904 131,051 0.012 1.51 0.78%
Marine Fisheries
(148)29,849 109,445 0.009 1.51 0.58%
Washington Street
Extension, Middle
and North (159,
187, 197).
84,866 209,427 0.018 1.51 1.16%
1 Several structural control structures have been proposed in these drainage areas. We assumed control based on below-grade
treatment train and used a conservative value of nitrogen removal (18%) at end of pipe treatment structures.
2.6.1.4 Opinions of Probable Cost
Based on this evaluation, W&C developed the following Table 2-8 to provide an overview of most feasible nitrogen
management solutions and the cost per pound of Total Nitrogen reduced through several management activities.
Costs are preliminary and should not be used for budgeting.
Table 2-8: Most Feasible N Reduction Stormwater Activities and Cost Estimates
Management
Activity
Annual
Nitrogen
Load
Reduced
(lb)
Opinion of
Cost Per Year
Low/High Opinion of
Cost Per Year
Cost per lb
removed
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Street Sweeping1 114 $60,000 $50,000/$70,000 $438-$614
Catch Basin
Cleaning1 99 $80,000 $70,000/$90,000 $707-$909
Structural
Stormwater
Controls2
162 $66,000 $66,000/$264,000 $407-
$1,629
1 Cost estimate spreadsheets developed by W&C based on regional operations data. Data input
includes assumed hourly labor rate, numbers of catch-basins cleaned and miles of roadway swept,
disposal costs and normalized hourly rate for equipment use, maintenance and depreciation.
2 Utilized Construction Cost Estimates published by Earth Tech in Outfall Evaluation, 2005.
Assumed $250,000 for Consue Springs drainage area, which was not included in original 2005
study. As projects identified in 2005 study included drainage enhancement as well as water quality
efforts, W&C assumed that 25% of overall project cost were related to stormwater water quality
improvement for the base opinion of cost. This percentage was based on average % of
construction cost of 17% for stormwater control structure of all projects. High opinion of cost
assumed drainage components of project must be completed to provide water quality benefit. All
capital costs converted to annual costs with annual debt repayment for 2% interest over 20-year
loan. This does not include maintenance, which is assumed in catch basin cleaning program cost.
Recommendations2.6.2
Implementation of structural and heightened non-structural controls is not recommended at this time. These activities
will require substantial capital costs, including purchase of multiple high efficiency regenerative air-vacuum sweeping
trucks, construction of structural controls to treat nitrogen at outfalls that drain portions of the downtown area, as well
as continued annual expenditures on ongoing implementation of sweeping and catch basin cleaning, and
maintenance of the structural controls. Preliminary estimates show both capital and ongoing operational costs
associated with these practices are very high per kg of nitrogen removed, as compared to management of fertilizer,
septic systems, and sewering. Based on discussions with Town Staff about implementation of these potential non-
structural and structural control practices to reduce nitrogen loading to the harbors from impervious cover, Woodard
& Curran has recommended the Town implement the following activities to reduce nitrogen loading from impervious
cover runoff:
Continue its current street sweeping and catch basin cleaning operations in the downtown area;
Develop local bylaw and regulations to manage stormwater runoff during construction and post-construction
for new development and redevelopment;
Implement “adaptive management” for street sweeping, catch basin cleaning, and structural BMPs as
needed based on water quality results in Nantucket and Polpis Harbors; and
Develop a comprehensive island-wide Stormwater Management Master Plan. This Plan should build off of
related work completed to date including: the drainage system map and the evaluation of drainage outfalls
in the downtown area to develop a Plan that integrates existing and future stormwater capital planning,
drainage operations and maintenance efforts, regulatory requirements, public outreach and involvement,
previously completed watershed and water quality work, and known local problems such as areas prone to
flooding. This Master Plan will help the Town to holistically understand its stormwater assets, water quality
and quantity issues, budgetary costs and drivers for these costs, and develop a sustainable plan for long-
term management of stormwater throughout Town. Ultimately, a Master Plan can set the framework for a
stormwater financing mechanism. This Plan is necessary to protect public and environmental health,
address water quality issues, and protect public and private drinking water supplies. Although the Town is
not regulated under EPA’s Phase II Small Municipal Separate Storm Sewer System (MS4) stormwater
Town of Nantucket (#225139.00)2-42 Woodard & Curran
Final CWMP Update Report Volume I October 2014
program, the Town does have a need to manage its stormwater runoff to prohibit discharges from causing
or contributing to exceedances of water quality standards. In addition, the Town has aging stormwater and
sewer infrastructure, therefore has a high potential for illicit connections or illicit discharges to the drainage
system from improper connections or failing sewer pipes. The Plan will also preserve recreational areas
used for swimming and boating, commercial fisheries, and protect endangered species habitat.
2.7 FERTILIZER UPDATE
At the Town’s 2010 Annual Town Meeting, a Home Rule Petition, Article 68, to regulate fertilizer application was
brought forward for vote. The voters put the Article on hold and formed the Article 68 Work Group to review and
make constructive changes to a Home Rule Petition, Article 68 with the intent of reworking the Article for vote in the
future. The 2010 Home Rule Petition sought to regulate the application of fertilizer, which was not supported by local
landscapers and the golf clubs on Island. The new group was tasked with making constructive changes to the 2010
document and perfecting the original language so that the town could bring it forward with support to approve and
pass it. The Article 68 Work Group worked over the following two years (2010 -2012) and came up with the Best
Management Practices for Landscape Fertilizer Use on Nantucket Island. The Work group reached out to various
technical experts from the scientific community, as well as a host of local professionals, who all contributed to the
final BMP. The purpose of the BMP is to provide a science-backed guideline for fertilizer use that reduces excess
nutrient loading into nitrogen and phosphorus sensitive water resources where contamination is degrading not only
the environment, but, aquatic life and human health and welfare as well. A copy of the BMP can be found on the
Town’s website under Natural resources Department at:
http://www.nantucket-ma.gov/Pages/NantucketMA_NatRes/BMP%20final%202012-03-05.pdf.
After extensive research and a wide public outreach/education program, the BMP was finally approved and adopted
by the Board of Health in 2012 and went into effect in January 2013. The main components of the BMP include
prohibiting fertilizer application during specific calendar times and during heavy rains. The Regulation also limits the
use of nitrogen enriching fertilizer based on land area and no more than one application every two weeks. The
Regulations contains an education component, as well as a licensing provision for professional landscapers who
must pass a test before receiving a license to apply.
The Regulations are a critical component to limiting the nitrogen loading that has been well documented through the
Massachusetts Estuaries Program (MEP) in multiple areas on Island as degrading the coastal embayments and
estuaries. Nantucket Harbor and Polpis Harbor are two of the main areas on Island that have been documented by
the MEP as suffering from degradation due to nitrogen loading from fertilizer. Based on the MEP reports, the
Massachusetts Department of Environment Protection (MassDEP) has issued Total Maximum Daily Loads (TMDLs)
that mandate a reduction of the nutrient loading in order to maintain healthy water quality in the receiving waters. The
BMP developed by Nantucket will work in tandem with other water quality initiatives to reach and maintain healthy
water quality Island-wide.
At the time of this Report writing, Local Regulation 75.00 work to implement is still a work in progress. The Natural
Resources Department is overseeing the Fertilizer Program and has worked with the University of Massachusetts
Amherst Extension Office in developing and instructing the educational course that is required in order to obtain the
mandated license. As of this Report writing, the course has been offered on four separate occasions with significant
attendance at each. Nearly 300 licenses required for commercial fertilizer use have been issued. Based on the
demand, the course will continue to be offered throughout May and periodically throughout the summer. The Town is
looking into offering the classes in Spanish so that they can reach out to as many landscapers as possible. Additional
goals are to offer classes in gardening, flower beds, trees and shrubs. The Town has begun the enforcement of the
Regulations and is finding this leads to compliance in the majority of the cases. The Town is also working to educate
its own staff with the entire body of the Natural Resources Department having completed the course, as well as
employees from the DPW and Public school system.
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Fertilizer reduction scenarios are detailed in the second round of model runs completed for Nantucket and Polpis
Harbors in order to identify TMDL solutions in these impacted areas on Island. While fertilizer scenarios were not
completed in all areas of the Island subject to MEP, the very fact that the Town is implementing these Regulations
should serve as a piece of the proposed Adaptive Management Plans developed for each embayment area that is
the subject of a MEP Report. All N reductions that are as a result of fertilizer reductions will be shown on the
subsequent water sampling completed in the Town’s Annual water quality Program. There is data to support the
reduction of loadings included in work done in the Chesapeake Bay area. Research in this watershed, documented in
the approved final report titled “Recommendations of the Expert Panel to Define Removal Rates for Urban Nutrient
Management”, shows urban nutrient management practices such as: fertilizer regulatory controls, training, and
education can reduce from 6 percent up to 20 percent of nitrogen loads to a water-body. Furthermore, 20 percent
reduction is seen in high risk parcels (such as those adjacent to waterbodies, over-irrigated lawns, those with high
water tables, those abutting closed drainage systems, etc.- much like the ones in the Nantucket Harbor and Polpis
Harbor watersheds).
For the purposes of evaluating possible load reductions from fertilized areas, Woodard & Curran has estimated the
potential reduction in application rates, given the Town’s current efforts to manage private fertilizer use through the
Board of Health Regulation 75.00 and the Town’s Best Management Practices for Landscape Fertilizer (“BMP
Manual”). Among other requirements, the Regulation requires the Town’s Board of Health to maintain an education
program based on the BMP Manual. This manual provides science-based fertilizer application guidelines for
residents and commercial applicators, which will result in a reduction of fertilization application over current practices.
Given the passage of local regulations, the creation of the BMP Manual and active education and enforcement
efforts, nitrogen reduction through fertilizer management will be realized in the Nantucket Harbor and Polpis Harbor
Watersheds. At this time, W&C has taken a conservative approach to modeling load reductions for fertilizer inputs.
To estimate the potential load reduction from fertilizer application, we looked to typical fertilizer products currently
available for retail purchase and the TN application rate if following manufacturer’s guidelines. The typical products
contain guidelines that will result in an average application of 0.9 lbs per 1000 sq. ft for a single bag.
W&C has assumed that through municipal outreach and enforcement at least 75 % of the residential and commercial
properties in the Nantucket Harbor and Polpis Harbor watersheds will reduce fertilizer application by just over 15%,
therefore reducing the overall nitrogen input from fertilizer by 12.5% of the quantity estimated in the TMDL model.
This is consistent with the work completed in the Chesapeake Bay Watershed. Therefore, we estimate that the
overall fertilization application rate will be approximately 0.945 lbs per 1,000 square feet.
Table 2-9:MEP Fertilizer Target Load Reductions
Watershed
Original Load
(kg/day)
Load Reduction -
Fertilizer
Management1
(kg/day)
Total Load
Reduction Target
(kg/day) from
TMDL
% of Target Load
Reduction
Town Harbor 4.10 0.512 1.51 33.9%
Quaise 0.16 0.020 0.98 2.1%
Polpis 0.18 0.023 1.34 1.7%
Head of Harbor 0.15 0.019 1.07 1.8%
Total 4.59 0.574 4.9 11.7%
1: Assumed 75 percent of parcels reduce application by 12.5 percent annually
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It is the recommendation of this CWMP Update that the Fertilizer regulation be fully implemented Island-wide to
further reduce nutrient loadings to the water resources. In Nantucket and Polpis Harbor alone, fertilizer reduction will
supplement expensive structured solutions to reduce nutrient degradation in these waters such as sewering, raising
the east and west jetties in Nantucket Harbor, dredging Polpis Harbor for a wider flushing on tides and stormwater
solutions. The Model Run Scenarios completed in 2014 support fertilizer reduction in reducing N loads. Fertilizer
reduction is a far less costly solution than others and has significant value in contributing to the overall health of our
water resources. Local Regulation 75.00 can be accessed on the Town’s website through the Board of Health at
http://www.nantucket-ma.gov/Pages/NantucketMA_Health/forms/75.pdf.
2.8 LANDFILL MINING
Nantucket has operated a landfill adjacent to upper Long Pond for a number of decades. In 2004 when the
CWMP/EIR was completed, the Massachusetts Estuaries Program (MEP) had not started the study of nitrogen
loading thresholds in this area, so the landfill was not included as part of criteria evaluated in the determination of
“Need’ for wastewater. The landfill is north of the Madaket Needs Area, east of the Warren’s Landing Need Area and
is adjacent to the east of upper Long Pond, which is part of the overall Madaket Harbor Watershed. As a result of the
2010 MEP Report, the landfill became a contributing nitrogen loading factor to the thresholds developed in the study
and as such is taking on a more prominent part of this CWMP Update Report in order to evaluate its importance in
developing a solution to the MassDEP issued Draft Total Maximum Daily Load (TMDL) for Madaket Harbor and Long
Pond.
When the CWMP/EIR was completed in March of 2004, the Town was accepting compost residual and construction
and demolition (C&D) materials into the landfill. This process continued until MassDEP amended the Waste Ban in
2005 and then in 2006 instituted a full ban on C&D materials in landfills. In the time before the waste ban, Nantucket
was becoming aware that it was running out of space for solid waste at the landfill and that to have to ship all solid
waste off Island in the near future would be cost-prohibitive. In the late 1990s, the Town hired Waste Options, Inc. to
integrate a solid waste disposal program. Tasks included landfill clean-up, recycling and composting. Fast forward
sixteen/seventeen years later and Nantucket’s state of the art landfill facility has far exceeded original goals. Today
they recycle over 80 percent of materials that would have gone into the landfill. The composting system results in
landfilling no more than 20 percent of incoming materials and the Town integrated a landfill mining and closure
program. A report on the status of the landfill capacity written in July 2012 estimated that of cell 2B, which is the
current active cell, had in the range of 10,000 to 20,000 cubic yards of airspace remaining to accept residual
materials. This space is estimated to last until FY2015. Construction of the next cell, Cell 2C, can be deferred until
approximately FY2014 or FY2015.
In 2010, the Massachusetts Estuaries Program (MEP) released the Report entitled, “Linked Watershed-Embayment
Model to Determine Critical Nitrogen Loading Thresholds for Madaket Harbor and Long Pond, Nantucket,
Massachusetts”. The Report evaluated the complex coastal embayments in the Madaket Harbor watershed and
completed an analysis to determine the necessary nitrogen-management decisions that Nantucket needs to make in
order to preserve and protect the embayments areas and water resources that are becoming severely degraded due
to over enrichment of nitrogen. The Report detailed nitrogen loading thresholds for the Town to utilize as
management tools. The Report is a science-based approach utilizing water quality data, habitat assessment, oxygen
measurements and benthic community structures to assess the overall health of the watershed. Based on the results,
land use specific unattenuated nitrogen loads to the overall watershed system were detailed, including overall
contributors, as well as locally controllable contributors. The landfill is included as an overall contributor at 10 percent
and as a locally controllable contributor at 21 percent. See Figure IV-6 from the MEP Report. As a result of the MEP,
MassDEP issued a Draft Total Maximum Daily Load (TMDL), which is a regulatory driver that mandates Nantucket
find a solution, or solutions to meet target thresholds for nitrogen loading in the overall Madaket Harbor Watershed.
This CWMP Update is scoped with delivering a plan to do exactly this.
Town of Nantucket (#225139.00)2-45 Woodard & Curran
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The MEP report suggests that the current mining of the landfill results in a reduction of nitrogen loading in this area.
The landfill is a “piece” of the locally controllable portion of nitrogen loading and is a part of the overall solution to
meeting the draft TMDL that MassDEP issued in August 2011.
With the current mining operation of the landfill, material in the existing unlined cell is removed, sorted, portions
passed through a digester and/or recycled. Some materials that cannot be recycled are then shipped off Island and
what cannot be recycled or reused are then placed in lined cells, which are then capped preventing contamination to
the groundwater. This process reduces the potential for nitrogen loading to the groundwater that ultimately flows into
the watershed via Long Pond, Madaket Ditch, Hither Creek and ultimately Madaket Harbor. As this process
continues, nitrogen loading is further reduced to the overall watershed.
Nantucket undertakes Town-wide water quality monitoring on a yearly basis and includes Madaket Harbor and Long
Pond sampling. As of this report writing, the Town received the 2012 results in a Report entitled, “Town’s Water
Quality Monitoring Assessment of the Nantucket Island-Wide Estuaries and Salt Ponds”. The data collected for Long
Pond shows a reduction in Total Nitrogen, approximately 40 percent less, from 2010 data results. While this is a
positive step in nitrogen loading reductions to this watershed, it will need to be monitored very closely in order to
determine if it represents a real reduction as a result of the landfill mining and closure or merely a natural inter-annual
variation. The 2013 summer water quality monitoring continues to show the N reduction trend continuing as shown in
the 2012 results. This will continue to be monitored in the future.
Overall, the landfill reduction, clean-up process is a positive course of action on multiple levels. It is providing a vital
clean-up and storage effort to the limited amount of space available on Island through clean-up and recycling. The
2013 summer sampling results also continue to show the trending of N reduction, which is another of the overall
benefits of the landfill program and will contribute to meeting the Draft TMDL set in this embayment area.
Refer to Appendix C for copies of landfill materials used to summarize this section.
2.9 POTABLE WATER SYSTEM EXPANSION UPDATE
Since the 2004 CWMP, the Town Water Department has installed water mains into various areas of Town that
previously were limited to on-site wells. During the Needs Analysis conducted in 2001, Madaket Needs Area was
completely dependent on on-site wells for its potable water. In 2010, public water was extended along Madaket Road
to service a small portion of the upper Madaket Needs Area and all of Warren’s Landing. While the entire Needs Area
is not serviced with public water, it was brought from Warren’s Landing to Massasoit Village and then in 2011 to F
Street, Tennessee Avenue to North Cambridge street ending on Little Neck Way. This mainly accounts for the
northern portion of the Madaket Needs Area leaving the middle and southern portions to continue to rely on private
wells. The Town also brought a 2,000,000-gallon water storage tank located in North Pasture into service in 2010.
Additionally, Wannacomet Water is in the process of extending water mains on Hummock Pond Road to service the
Cisco and Hummock Pond area of the Island.
Refer to Figure 2-19 for a map of the existing potable water system (not including Cisco and Hummock Pond as this
work is in progress as of this Report writing).
Potable water comes from three groundwater wells located throughout the mid-Island located in Nantucket’s Sole
source Aquifer. The Milestone Well #2 and State Forest Well #3 are protected by Zone Is with a radius of 400 feet
surrounding the well. The Milestone Well #1 has a Zone I protection that extends 250 feet from the perimeter of the
well. The drinking water comes from two different levels of the aquifer. The water system distributes water through a
network of water mains that range in size from two inches up to sixteen inches in diameter.
According to the Water Department, in 2012 the Town produced and delivered 612,314,000 gallons of drinking water
from all of its wells. Highest demand was on July 6, 2012, which is expected given the population surges during this
Town of Nantucket (#225139.00)2-46 Woodard & Curran
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summer period. Nantucket relies entirely on rainfall to recharge its Sole Source Aquifer, with 2012 receiving 32
inches in rainfall, with average rainfall recharge around 43 inches per year.
Wannacomet Mission Statement
“” The Wannacomet Water Company shall strive to provide high quality drinking water that exceeds all established
Federal and Commonwealth drinking water standards, provide the highest level of customer and water related
services achievable, educate and inform the public of the need to protect Nantucket’s water resources, and to
accomplish this mission using prudent utility practices and responsible fiscal management.”
Refer to Appendix D for copies of Wannacomet Water Company materials and information.
.
Legend
Water Mains
Pond
Wetland
COMPREHENSIVE WASTEWATERMANAGEMENT PLAN UPDATETOWN OF NANTUCKET, MA
WATER SYSTEM
FIGURE 2-19
SCALE: 1" = 1.25 MILES
DATE: FEB. 2014 JOB NO.: 225139
DOC: WATER.MXD
DRAWN BY: JSM/RTB SOURCE: MassGIS & Town
Shimmo
Monomoy
Miacomet
SiasconsetCurrently Sewered
TownCurrently Sewered
HummockSouth
HummockNorth
Warren'sLanding
Madaket
Somerset
PLUS
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2.10 NANTUCKET SEWER ACT OF 2008
On December 18, 2008, the Governor of Massachusetts under the Acts of 2008, Chapter 396, signed an act
authorizing the establishment of the Nantucket Sewer Commission and Sewer Districts (“Nantucket Sewer Act”) into
law. The Act was effective on July 1, 2008. Final approval was on December 17, 2008. This Act authorized the Town,
through the Sewer Commission (Board of Selectmen) to design, construct, maintain and operate a sewer system
within designated sewer districts. The Act contains twelve sections as follows:
Section 1 Lay out, plan, construct sewers
Section 2 Maintain sewer connections
Section 3 Selectmen to act as Sewer Commissioners
Completed by 2/3 vote
Section 4 Make policies, finances and goals
Subject to Charter of the Town of Nantucket
Section 5 Eminent Domain provisions
Section 6 Establish Enterprise Fund
Section 7 Revenues of Sewer Funds
Section 8 Prescribe annual charges, connection fees,
assessments, privilege fees et al
Section 9 Adopt Rules and Regulations
Section 10 Defined Sewer Districts
Section 11 Municipal Buildings
Section 12 Act takes place July 1, 2008
Final approval of the provisions of this Act by the Town was on December 17, 2008.
Once the CWMP Update is finalized and approved, a review of the Act needs to take place and any appropriate
amendments to such Act made based on changes between the 2004 CWMP and 2013 CWMP Update. See
Appendix E for a copy of the Act.
2.11 SEWER CONNECTION POLICY
The Town enacted Local Regulation 69.00, “Connections to New and Existing Publicly Owned Sanitary Sewer Lines”
on May 7, 2003 under the jurisdiction of the Board of Health (BOH). The intent of the Regulation is as stated, “to
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further protect all existing and potential ground water, surface waters, harbors and estuaries on Nantucket Island
from contamination from septic system failure”. In addition to the above intent, this Regulation should serve to protect
the Island’s water resources from nutrient degradation from on-site wastewater systems by mandating that in areas
where sewer infrastructure is operational existing properties officially abandon their on-site systems and hook into the
municipal sewer. This is extremely important in areas where nitrogen degradation is documented by the
Massachusetts Estuaries Program (MEP), specifically Nantucket Harbor area where municipal sewer is available at
the time of this report writing.
This Regulation mandates that properties abutting a sanitary sewer line installed or approved by the Town of
Nantucket Department of Public Works connect the structures located on the property within two years notice of
availability. If the property is located within an environmentally sensitive area as defined by the Nantucket BOH and is
located in an area where municipal sewer lines are available, the property must be connected within six months of
notice of availability, weather permitting, but cannot exceed one year in any case.
Local Regulation 69.00 takes into account those properties that have a newer on-site system and affords the property
owners a deferral period to abandon their system. If a system was installed less than five years before sewer lines
were activated, a variance to connect to the sewer may be granted by the Board of Health. This affords the property
owner time to utilize the on-site system and defrays connection costs that would be incurred connecting to the
municipal sewer. This section of the Regulation is not a given, but a “consideration” by the BOH taking into account
site specifics. For example, if the property owner replaced their system within five years of municipal sewer becoming
operational, but is in a nitrogen or environmentally sensitive area where it was deemed detrimental to continue with
the on-site system, then the BOH reserves the right to mandate a connection.
Regulation 69.00 also provides a Right of entry onto private property with reasonable notice in order to ensure
compliance of the Regulation. It also stipulates the penalties for not conforming to it.
At the time of this report writing, a review of municipal sewer connections in the Nantucket Harbor Watershed Area
that are included within the Town Sewer District was completed in order to determine properties currently being billed
for sewer usage and those existing and developable parcels that are not receiving bills. The results show that there
are existing properties that are showing as not connected at this point in time. These were reviewed by the DPW for
any errors in billing and it has been determined that this overall number is divided into two categories:
Parcels connected to sewer, but not receiving bills1.
Parcels still on on-site wastewater disposal systems2.
The DPW has worked with the Wannacomet Water Company (WWC) rechecking billing records as the WWC
processes the water and sewer bills for the Town. The Sewer Planning Work Group (SPWG) took on the charge of
addressing the properties that currently receive sewer service, but are not billed. As of June 2013, the SPWG sent a
letter of recommendation to the Board of Selectmen, the Town’s Sewer Commissioners, regarding these properties.
The recommendation includes billing these properties for the last three years of sewer service (as directed by Town
Counsel) and affording a payback period of three years. Discussions are on-going as to the charging of privilege fees
to these properties as has been the protocol with other properties connecting into the system. There is also on-going
discussion on the best manner to notify each of these property owners of the final decisions made by the Sewer
Commissioners that impact future actions.
There are also many properties within the Town Sewer District that have not connected into the sewer system even
though the Town has mandated that they do so. A recommendation of this CWMP Update is to notify all existing
parcels not connected into the system of the sewer availability and afford them a minimum time limit to connect to the
sewer lines based on Regulation 69.03, item B-based on location within an environmentally sensitive area. The Town
Sewer District is located within an environmentally sensitive embayment as detailed in the Massachusetts Estuaries
Report (MEP). The Town is also under the mandate of a TMDL in Nantucket Harbor to reduce nutrient loading. The
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MEP details this nutrient loading as being contributed by on-site septic systems. It is important to remove these on-
site systems to reduce the nitrogen loads that are contributing to the degradation to the Harbor embayments. For
those undeveloped, but developable parcels, a recommendation to apply to hook into the sewer as soon as the
property is developed will be sent. No undeveloped property developed within the existing Town Sewer District will be
approved with an on-site wastewater disposal system-it must connect to the Town’s sewer system. It is
recommended that this Regulation be evaluated and enforced through the appropriate jurisdiction (s). Refer to
Appendix E for copies of Board of Health Local Regulations.
2.12 SEPTAGE MANAGEMENT PLAN
A Septage Management Plan (SMP) was developed as part of the 2004 CWMP and formally adopted by the Town.
The goal of the SMP was to provide the tools, options and resources necessary for the Town to manage on-site
wastewater disposal systems, both in areas identified and approved as Needs Areas while they wait for sewer
infrastructure to become implemented and active in their area. The SMP is particularly directed towards those areas
on Island where on-site wastewater disposal is the long-term solution where a well-managed plan will act as “sewer
avoidance” in the long-term. The SMP long-term goals were developed for multiple reasons;
To protect and maintain public health
Ensure the protection of both groundwater and surface water resources
Maintain environmental, economic and recreational water resources
Retain local control of on-site systems without regulatory or management intervention
Preserve and protect property values
Maximize options for on-site management with both local and regulatory requirements
Identify staffing and financing needs in the local jurisdiction, the Nantucket Board of Health
The SMP was officially adopted by the Board of Selectmen on November 9, 2005. The Board of Health is the official
jurisdiction for implementing and maintaining the SMP. As part of this CWMP Update, we met with the DPW Director
and Board of Health Agent to review the individual components of the SMP to ascertain where items have been
implemented, milestones reached and areas where an action plan needs to be developed in order to implement. The
SMP is divided into seven major sections as follows:
Regulations1.
Inspections2.
Staffing3.
Funding4.
Record Keeping5.
Education & Outreach6.
Management of Onsite Sewage Disposal Systems7.
Each section contains pieces that have been implemented to date, as well as items that have not yet been
addressed. Those items not yet addressed are due to overall budgetary and staffing issues that are common
throughout the state over the past decade because of a failing economy. Nantucket has done a good job of
prioritizing sections in the SMP for implementation with available budgets. For instance, the Town has addressed the
major watershed protection areas with the adoption of the new Districts including regulations, inspection schedules,
and enforcement procedures. The following details each of the seven elements of the SMP with a summary of
completed items and those on track for future implementation:
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Regulations2.12.1
Regulations include the adoption of new Regulations, as well as variance provisions and available repair and escrow
options. This element also addresses enforcement procedures, maintaining an on-going discussion with the state
regarding Title 5 changes and assisting with the areas on Island subject to study in the Massachusetts Estuaries
Program (MEP). Table 2-10 detail the progress made in adopting new regulations and escrow/repair options
Table 2-10: Septic Management Plan Regulations Implemented to Date
Component Adopted As Date
Mandatory Sewer Connections in Sensitive Areas Local Regulation 69.00 May 2003
Nantucket Harbor Watershed Regulation Local Regulation 68.00 May 2005
Madaket Harbor Watershed Regulation Local Regulation 53.00 June 2006
Nitrogen Sensitive Areas Local Regulation 54.00 August 2009
Identify Remaining Needs Areas / Environmentally Sensitive Areas On-Going
Adopt and Implement Regulations for Remaining Needs
Areas/Environmentally Sensitive Areas – Hummock Pond - Zones A
& B
Local Regulation 55.00 September 2010
Amended February
2013
Adopt Provisions of Community Septic Management Program Annual Town Meeting 2011 April 11, 2011
Administrative Consent Order for Septic Repair Deferral Local Regulation 59.00 September 2012
As is shown in the above Table, Nantucket has been proactive in its approach to adopting new regulations for the
preservation and protection of its water resources. Each Local Regulation contains a purpose, procedure, definitions,
and enforcement provisions.
Additionally, the Town has adopted a means to fund on-site wastewater system repairs through Town Meeting
approval. April 2011 Annual Town Meeting approved the Town’s participation in the Massachusetts Community
Septic Management Program (SPM), for an initial borrowing of $1,000,000 with an additional $1,000,000 available,
for the repair/upgrade of on-site wastewater systems. This Program is a collaboration of MassDEP, The Executive
Office of Administration and Finance, The Office of State Treasurer and the Department of Revenue to provide
funding and assistance to Nantucket homeowners to repair, upgrade, replace on-site wastewater disposal systems
for long-term sustainability, especially in environmentally sensitive areas, as well as those areas determined long-
term sustainable with on-site systems.
Additional, this funding can be utilized in the future with property owners’ sewer connections in identified Needs
Areas. To date, the Town has lent out $478,450 through this Program. These loans are targeted toward those areas
within environmentally sensitive watersheds, including systems that are located within the Town’s Wellhead
Protection Zone.
The Board of Health has developed an Administrative Consent Order process (ACO) that will alleviate property
owners from having to pay for an expensive upgrade/repair of an on-site wastewater disposal system and essentially
pay again when municipal sewer becomes operational in the area. If a person currently owns and/or operates an on-
site wastewater disposal system on property that is located in a proposed future municipal sewer service area and
identified as a Needs Area in the CWMP Update Document, (which the Board has determined requires an upgrade
pursuant to 310 CMR 15.00 (Title 5)and as defined in the Board of Health Regulations under Local Regulations
51.00, 53.00, 54.00, 64.00, and 66.00), the Nantucket Board of Health has determined that the property owner may
not be required to undertake construction of a major upgrade and/or major repair or new on-site wastewater disposal
system at this time.
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Once approved, the property owner can enter into an ACO with the Nantucket Board of Health and meet the
minimum local requirements until a municipal sewer is operational in the area. The Board of Health reserves the right
to require any property owner with a failed septic system, in an area where future phases are being considered and
where connection to the municipal sewer system is not available because no municipal sewer exists in that area or
that the existing sewer system has no available capacity in that area to accommodate a connection, to enter into an
Administrative Consent Order (ACO). Once the ACO is recorded with the deed at the Nantucket County Registry of
Deeds and the first payment made to the Finance Department, the property owner will be allowed to make repairs to
the failed septic system that would normally not be allowed such as, but not limited to, installing a replacement leach
area to Title 5 minimum standards. All repairs must be approved and permitted by the Health Department prior to
installation.
This Program affords the property owner in a Needs Area where municipal sewer is targeted this option to avoid
paying for an expensive repair and then having to pay a capital cost for municipal sewer-essentially having to pay
twice for wastewater services. The ACO Program is currently underway in the Madaket Needs Area. As the CWMP
Update confirms additional Needs Areas from the 2004 CWMP, those areas will be afforded the use of Local
Regulation 59.00.
The Board of Health maintains communication with the state with regards to Title 5 elements as well as is involved
regionally through the Barnstable County Department of Health on these issues. At the time of this Report writing,
revisions to Title 5 are under public comment and due to be finalized sometime during summer 2013.
The Board of Health is one of multiple Nantucket Departments involved with the Massachusetts Estuaries Program
(MEP), which is in its tenth year of studies on Island. To date, Nantucket Harbor, Polpis Harbor, Sesachacha Pond,
Madaket Harbor and Long Pond MEP studies are completed with either final or draft Total Maximum Daily Loads
(TMDLs) issued. Hummock Pond MEP has been completed through Town funding with SMAST. The MassDEP was
not partnered in this effort due to lack of state funding available. MassDEP has been sent a copy of the MEP Report,
but the Town has not received any formal response from the Department at the time of this Report writing. The MEP
areas are discussed in detail throughout this Report.
Inspections2.12.2
The Town revised its Title 5 inspection and certification standards in May 2005 with more detailed forms and more
formalized schedules. Based on the new Regulations discussed above, inspection schedules were developed with
letters sent to all impacted properties. The one-time inspections mandated through the Local Regulations are as
follows:
Nantucket Harbor Watershed – completed
Madaket Harbor Watershed – completed, with repair options underway
Hummock Pond – letters sent and Board of Health deferred until MEP Study is complete.
The majority of these inspections show failures of on-site wastewater systems. The failures are defined as “technical
failures” and due to high groundwater conditions. Hydraulic failures do happen, but are in the minority. These system
failures require immediate attention.
Staffing and Funding2.12.3
Staffing and funding are areas that the SMP has documented as an on-going issue, but to date has yet to be able to
fully address. Staffing and associated costs for the various areas in the Board of Health need to be updated to
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include the tasks currently under the BOH jurisdiction. The SMP contains recommended targets / timelines for this,
but due to budgetary constraints have not been revised. Staffing issues are reviewed annually for appropriate
updates on an on-going basis. The fee schedule and update recommendations in the SMP were completed in
October 2005 based on the then duties performed by the BOH. As of this Report writing, additions to local regulations
and subsequent duties need to be accounted for and a review of the October 2005 fee schedule updated
accordingly.
While the BOH has updated user fees, inspection fees and overall accounts receivables, these have not been
sufficient to support additional staffing needs. The BOH is not alone in this dilemma, as all Nantucket Town
Departments are working with smaller staffs carrying current workloads.
The BOH does not have staff targeted to research grants available, but various consultants working with the Board
have. At this time, there are very few, if any, available grant programs to supplement the activities in the BOH.
Staff currently processes the day to day activities of the BOH, which is far greater than SMP. The Community Septic
Management Program, ACO Program, Title 5, Local Regulations and all areas relative to on-site wastewater are
managed with existing staff.
Record Keeping2.12.4
The Board of Health maintains a central filing system for inspections, compliance, scheduling and tracking in the
PLUS Building. These files are shared with other Town Land Use Departments. A specific computer tracking
program, ACCESS, is used as a database to track all ACO users. Additionally, staff maintains computer records of
the Community Septic Management Program users. Under the SMP, it is recommended that the BOH purchase a
computer program to use as an overall accounting system with periodic updates, but due to the lack of available
budget, this has not been done.
The Town is working with Barnstable County on a cooperative program to maintain all Innovative and Alternative (I/A)
Wastewater Systems. This is a win/win for both entities as Nantucket will maintain jurisdiction over the approval of
systems, but Barnstable County Department of Health will become the operation and maintenance jurisdiction.
Barnstable now manages all I/A Cape-wide with a comprehensive database that tracks all systems, their repair
records, as well as their performance standards. Adding Nantucket’s systems to the data set will afford a wider and
more comprehensive record set for use by all. Barnstable is currently updating its database hardware and once
completed, Nantucket will join forces with this cooperative program.
Education and Outreach2.12.5
Since 1998, the BOH has done significant, on-going outreach when staff and budget are available. As part of both
the 2004 CWMP and on-going CWMP Update, on-site system education and outreach has been and continues to be
a major component. In addition, the BOH regularly holds public hearings that are widely publicized as part of its day
to day activities.
There have been public informational meetings, public workshops, informational posters and booklets developed,
printed and distributed. Many outreach tools have targeted specific areas of Town, recently with the adoption of the
ACO Program in Madaket/Warrens’ Landing multiple public informational meetings were held-some as part of the on-
going CWMP Update. As part of the ACO plan, a new Local Regulation 59.00 was drafted and the public weighed in
on the planning. The BOH held a Public Hearing to introduce the plan, the media published multiple articles on the
plan, CWMP Update Quarterly Updates with the Board of Selectmen featured the topic and brochures were
developed, printed and distributed educating the public on the plan. The BOH regularly participates in civic group
meetings on a number of topics, many wastewater related. All BOH meetings are posted as required by law and
open to the public.
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The proponents of the CWMP Update will continue to work with the BOH to solicit participation from the public with
matters related to on-site wastewater disposal systems, water quality and overall items related to wastewater as part
of the on-going planning.
Management of Onsite Sewage Disposal Systems2.12.6
The management of on-site wastewater disposal systems is under the jurisdiction of the BOH. The BOH has
established a tracking system to record inspection results, repair, replacement, and upgrade of systems whether as a
component of a Title 5 Inspection or because of change of use/modification of bedrooms. Inspection schedules as
part of the Local Regulations in approved watershed/water resource areas. These have been established for:
Nantucket Harbor Watershed area – Local Regulation 68.00
Madaket Harbor Watershed Area – Local Regulation 53.00
Madaket Harbor Watershed-Nitrogen Sensitive Area – Local Regulation 54.00
Hummock Pond Watershed Area* – Local Regulation 55.00
*Local Regulation 59.00 – defers inspection until MEP report is complete and sources of nutrient degradation are
identified.
While a significant amount of work has been conducted with regard to the management of on-site wastewater
disposal systems, further work is needed. One area is the establishment of a maintenance pumping schedule. This is
especially important in areas of seasonal use where systems are abandoned after Labor Day and not used again
until after Memorial Day. With no consistent flows to keep the system in check, contents become highly concentrated
and then when occupancies begin pre-summer, contents begin to discharge higher than normal concentrations and it
takes time to get back the on-site system into compliance. Then Labor Day hits and this scenario begins all over
again. Other areas where a pumping plan is important are those areas on Island deemed long-term sustainable with
on-site wastewater disposal systems. These are areas where no municipal sewer is planned in the future, so in
essence it is a “sewer avoidance” plan-it saves the municipality from having to fund costly capital projects and assess
those charges back to the user. The CWMP determined that these areas have the capability of maintaining on-site
wastewater disposal systems over the long-term as long as they are properly operated and maintained.
This is one area of the SMP where lack of budget has left the BOH without a means to fully implement an aggressive
on-site system pumping plan. It is a valid component that is reviewed annually by the BOH and until such time as
budget/staff afford, will remain with the system owners to do at their discretion.
The BOH established priorities such as establishing the Watershed Districts and mandated Title 5 Inspections, which
have formed the basis of water quality in many areas on Island. Available staff and budget directed towards these
tasks is vital and supports other coordinated endeavors such as with the Natural Resources Department. The BOH
will continue to review opportunities to implement the full On-Site Sewage Management Plan, such as is available
with Innovative / Alternative Systems at the Barnstable County Department of Health. There may be future
opportunities to include a pumping incentive plan here as well.
Summary2.12.7
Elements of the Septage Management Plan adopted in November 2005 have been prioritized and have been
implemented based on sections that represent the most environmentally valuable projects. While the Town has done
a good job representing these priorities, there still remain areas that need attention. Certainly staffing and budget
remain as high priorities for future consideration, both to maintain those items implemented to date, as well as to
bring to fruition other important areas that serve to benefit the Town. The complete SMP can be found in Appendix E
as well as copies of the relative Local Regulations.
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2.13 BOARD OF HEALTH ADMINISTRATIVE CONSENT ORDER
The Board of Health, with coordination from Town Administration and approved by MassDEP, developed an
Administrative Consent Order process (ACO) that will alleviate property owners from having to pay for an expensive
upgrade/repair of an on-site wastewater disposal system and essentially pay again when municipal sewer becomes
operational in the area. This process was possible because the Town was currently engaged in this Comprehensive
Wastewater Management Plan (CWMP) Update, which includes provisions for additional sewering of portions of the
Town. In addition, The CWMP Update is addressing areas of the Town where the Massachusetts Estuaries Program
(MEP), under the jurisdiction of the Massachusetts Department of Environmental Protection (MassDEP), is mandated
to reduce nitrogen loading in specific areas of Nantucket and to meet Total Maximum Daily Loads (TMDLs) set by the
state in Nantucket Harbor, Madaket Harbor, Long Pond, Sesachacha Pond and potentially other embayment areas of
Nantucket, including the Hummock Pond Area. Nantucket’s Harbor Watershed Districts (Nantucket and Madaket)
also detail reduction of nutrient loading from on-site wastewater disposal systems. In order to meet these mandates,
as well as provide options for property owners with failed on-site wastewater disposal systems in areas proposed for
municipal sewer, an Administrative Consent Order process has been established and approved by the Nantucket
Board of Health. The process is detailed in Section 2.12.1 above.
At the time of this Report writing, Madaket Needs Area is the one area approved for utilizing the ACO. It is assumed
that other areas on Island identified and approved as Needs Areas when the CWMP Update is completed will be
added to the Program.
The Nantucket Board of Health defines two types of failed on-site wastewater disposal systems that qualify under this
Regulation:
Hydraulic Failure
Technical Failure
Any property owner with such failed on-site wastewater disposal system, as determined above, and as approved by
the Board of Health and/or Agent, shall connect to the municipal sewer system upon its availability or, in specific
cases, upgrade and/or repair with certified Title 5 or approved Innovative Alternative system as per duly executed
ACO.
To date, several Madaket property owners have entered into the Program while the CWMP Update is completed and
an off-site wastewater solution is finalized for this Needs Areas.
Refer to Appendix E for copies of Local Regulation 59.00 and other approved ACO forms.
2.14 UPDATED NEEDS AREAS AND REVISED WASTEWATER FLOWS AND LOADS
A comprehensive review of the Needs Areas from 2004, as well as current and future conditions together with
updates of all changes that have taken place since the 2004 Report, a revised map of Needs Areas and associated
flows and loads took place. Refer to Figure 2-20 for the updated map.
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Needs and Study Areas Update2.14.1
The 2004 CWMP identified areas of the Town that were not deemed long-term sustainable with on-site wastewater
disposal systems due to a number of criterion. One criterion that was not in existence at this time was the
Massachusetts Estuaries Program (MEP) Reports, which identified areas impacted with nutrient loading, specifically
nitrogen. Nitrogen loading from various sources including on-site wastewater systems, stormwater, fertilizer and
various other sources were the subject of the MEP in southeastern Massachusetts, Cape, and Islands starting in
2003. When the 2004 CWMP was completed, none of the final results of the MEPs were completed so no nitrogen
loading criterion was added to the screening criteria utilized to determine the need for an off-site wastewater solution.
Now that the MEPs are completed we have redefined the Needs Areas and they are presented in Table 2-11.
Table 2-11: Updated Needs Areas and Area of Concern
Needs Area MEP Area
Madaket Madaket Harbor/Long Pond
Warren’s Landing Madaket Harbor/Long Pond
PLUS Town District - Nantucket Harbor/Polpis
Harbor
Monomoy Nantucket Harbor/Polpis Harbor
Shimmo Nantucket Harbor/Polpis Harbor
Hummock Pond North Hummock Pond
Hummock Pond South Hummock Pond
PLUS Parcels - Infill in Town Sewer District Multiple - Nantucket Harbor/Polpis
Harbor/Hummock Pond
2.14.1.1 Madaket and Warrens Landing Needs Areas
The Madaket Needs Area was evaluated in the 2004 CWMP and rated within the acceptable range to be determined
to be an area needing an off-site wastewater solution based on the existing criteria at that time. The 2004 CWMP did
not have the advantage of years’ worth of water quality testing that is showing significant and rising degradation to
Madaket Harbor, Hither Creek, Long Pond and other water resources in this geographical area since then. A major
change is the completed and approved Madaket Harbor/Long Pond MEP Report and subsequent Draft TMDL noting
the degradation in this area due to nitrogen loading from on-site wastewater disposal systems. The Madaket Harbor
MEP adds significant weight to the existing 2004 criteria to maintain this as a “Needs Area” and needing an off-site
wastewater solution. New zoning since 2004 in this area has further reduced potential for unwarranted growth due to
introduction of sewer infrastructure
The Madaket Harbor-Long Pond Embayment System as depicted in the MEP Report is a complex estuary with full
tidal basins (Madaket Harbor, Hither Creek) connected via Madaket Ditch to the brackish waters of Long Pond that is
influenced greatly by wetlands. Madaket Harbor is approximately 746 acres, semicircular in shape, open to
Nantucket Sound on its western edge, and open to the Atlantic on its southwest corner via a cut between Smith’s
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Point and Tuckernuck. The Harbor is a relatively shallow water body, 4-5 feet deep, with a deeper channel (6-9ft.)
running east and north to the coastline of the Sound. There are a few deeper channels that pre date Hurricane Esther
(1961), but much of the harbor has filled in because of the opening that was created by this storm. This condition
existed until Hurricane Gloria (1985), which enabled a closure of the gap to Smith’s Point. via drifting sand bars.
Because the southwest edge is open, circulation is high (flushing every 3 days), and water quality is good. Epiphytic,
and macro algae are limited in presence and density, and eel grass beds are healthy. Madaket Harbor and Long
Pond make up a unique ecosystem encompassing approximately 9 square miles. These two systems are
hydrologically connected via Hither Creek and the Madaket Ditch. Long Pond is somewhat isolated from the whole
system, and has been evaluated as having separate water quality issues. It is relatively narrow and winding with
depths of 4-6 feet with no deep basins.
Water quality results from 2010 to present show Hither Creek, Long Pond and North Head of Long Pond as not
meeting water quality standards. Madaket Harbor, which is an open marine basin, is not degraded as the other water
resources in the area are due to its high flushing component. The Clean Water Act and TMDL processes that
followed the MEP Report mandate that the Town develop and implement solutions for restoration of these water
resources. The MEP included the development of a target nitrogen load to determine the amount of total nitrogen
mass loading reduction required for system restoration. This included reducing the nitrogen load from the landfill,
which is an on-going process. In addition, a reduction of septic loading, 100 percent in the Hither Creek Watershed,
resulted in a 72 percent reduction in the entire Watershed.
The overall plan to meet the water quality standards is to continue with the landfill mining where water quality testing
is showing potential improvement. The 2012 Annual Water Quality results stated that Long Pond showed significantly
lower total nitrogen levels, 40 percent, in 2012 versus results shown in 2010. This trend is being further evaluated in
the 2013 Annual Water Quality Program to determine whether it is as a direct result of the landfill mining and can be
credited as such. In addition, the service area as defined in Figure 1-1 is proposed to be sewered, which is what the
2004 CWMP showed. The main difference in this Needs Area between 2004 and current is that the area included is
defined up to and not crossing over Millie’s Bridge.
The Needs Area encompasses approximately 342 acres, of which 222 are developed. There are 572 total parcels,
with 381 developed. Out of the total 572 parcels, 120 are municipal and/or conservation parcels and 71 are
undeveloped with only 17 of these potentially developable. With few available developable parcels, sewering this
Needs Area does not promote any unwanted sprawl. The Needs Area is plagued with severe soils, over 96 percent
comprised of Riverhead Sandy Loam, Berryland and Medisaprists. These soils are detailed, by the United States
Department of Agriculture Soils Conservation Service, as constrained since they percolate very fast and do not afford
time in the soil layers to cleanse before discharging into groundwater resulting in fast travel times into the
surrounding water resources. Also over 30 percent of soils in this Needs Area are associated with severe
groundwater limitation. Properties of this soil association are highly permeable , depth to seasonal high groundwater
and susceptibility to flooding. Riverhead Sandy Loams do not adequately filter the effluent, which leads to
groundwater contamination it is a moderately rapid permeable soil and does not provide sufficient filtering of effluent,
The other predominant soil associations in this Needs Area are Pawtucket Mucky Peats and Berryland, which are
both plagued as very wet soils and not conducive to septic tank absorption fields.
There are approximately 110 acres out of the total 342 acres of severe groundwater limitation, which limits the proper
absorption of effluent and leads to potential groundwater contamination. The majority of this Needs Area is serviced
with private water, thus posing additional threat from inadequately operating on-site wastewater disposal systems.
Over 53 percent of the area’s systems’ are located on lots less than or equal to ½ acres and over 55 percent were
built before 1978 (Creation of Title 5).
Based on qualifying criteria from the 2004 CWMP, together with the results of nitrogen loading documented in the
Madaket Harbor/Long Pond MEP, Madaket Needs Area qualifies as an area needing an off-site wastewater disposal
solution in this CWMP Update.
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2.14.1.2 Warrens Landing Needs Area
The Warrens Landing Needs Area was evaluated in the 2004 CWMP and rated within the acceptable range to be
determined to be an area needing an off-site wastewater solution based on the existing criteria at that time. The 2004
CWMP did not have the advantage of years’ worth of water quality testing that is showing significant and rising
degradation to Madaket Harbor, Hither Creek, Long Pond and other water resources in this geographical area since
then. A major change is the completed and approved Madaket Harbor/Long Pond MEP Report and subsequent Draft
TMDL noting the degradation in this area due to nitrogen loading from on-site wastewater disposal systems. The
Madaket Harbor MEP adds significant weight to the existing 2004 criteria to maintain this as a “Needs Area” and
needing an off-site wastewater solution.
The Madaket Harbor-Long Pond Embayment System as depicted in the MEP Report is a complex estuary with full
tidal basins (Madaket Harbor, Hither Creek) connected via Madaket Ditch to the brackish waters of Long Pond that is
influenced greatly by wetlands.
Warren’s Landing is part of the overall Madaket Watershed. According to the Town’s 1990 Water Resources Plan
Report, the groundwater in Warren’s Landing flows directly towards Long Pond and Madaket Ditch, which are both
impacted with nutrient degradation per the MEP Report.
The Warren’s Landing Needs Area is north of the Madaket Needs Area just east of Long Pond and north of Madaket
Ditch in the Madaket Harbor Watershed. Madaket Harbor is approximately 746 acres, semicircular in shape, open to
Nantucket Sound on its western edge, and open to the Atlantic on its southwest corner via a cut between Smith’s
Point and Tuckernuck. The Harbor is relatively a shallow water body, 4-5 feet deep, with a deeper channel (6-9ft.)
running east and north to the coastline of the Sound. There are a few deeper channels that pre date Hurricane Esther
(1961), but much of the harbor has filled in as a result of the opening that was created by this storm. This condition
existed until Hurricane Gloria (1985), which enabled a closure of the gap to Smith’s Point. via drifting sand bars.
Because the southwest edge is open, circulation is high (flushing every 3 days), and water quality is good. Epiphytic,
and macro algae are limited in presence and density, and eel grass beds are healthy. Madaket Harbor and Long
Pond make up a unique ecosystem encompassing approximately 9 square miles. These two systems are
hydrologically connected via Hither Creek and the Madaket Ditch. Long Pond is somewhat isolated from the whole
system, and has been evaluated as having separate water quality issues. It is relatively narrow and winding with
depths of 4-6 feet with no deep basins.
Water quality results from 2010 to present show Hither Creek, Long Pond and North Head of Long Pond as not
meeting water quality standards. Madaket Harbor, which is an open marine basin, is not degraded as the other water
resources in the area are due to its high flushing component. The Clean Water Act and TMDL processes that
followed the MEP Report mandate that the Town develop and implement solutions for restoration of these water
resources. The MEP included the development of a target nitrogen load to determine the amount of total nitrogen
mass loading reduction required for system restoration. This included reducing the nitrogen load from the landfill,
which is an on-going process. In addition, a reduction of septic loading, 100 percent in the Hither Creek Watershed,
resulted in a 72 percent reduction in the entire Watershed.
The overall plan to meet the water quality standards is to continue with the landfill mining where water quality testing
is showing potential improvement. The 2012 Annual Water Quality results stated that Long Pond showed significantly
lower total nitrogen levels, 40 percent, in 2012 versus results shown in 2010. This trend is being further evaluated in
the 2013 Annual Water Quality Program to determine whether it is as a direct result of the landfill mining and can be
credited as such. In addition, the service area as defined in Figure 1-1 is proposed to be sewered, which is what the
2004 CWMP showed. The main difference in this Needs Area between 2004 and current is that the area included is
defined up to and not crossing over Millie’s Bridge.
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Data from 2004 details this Needs Area encompasses approximately 49 acres, of which 26 are developed. There are
99 total parcels, with 68 developed. There are 19 undeveloped parcels of which 8 are developable. With few
available developable parcels, sewering this Needs Area does not promote any unwanted sprawl. New zoning since
2004 in this area has further reduced potential for unwarranted growth due to introduction of sewer infrastructure.
The Needs Area is plagued with severe soils, approximately 100 percent Evesboro Sands that are detailed by the
United States Department of Agriculture Soils Conservation Service as constrained as they percolate very fast and
do not afford time in the soil layers to cleanse before discharging into groundwater and thus travel fast to the Pond.
Properties of this soil association are highly permeable , depth to seasonal high groundwater and susceptibility to
flooding. Evesboro Sands do not adequately filter the effluent, which leads to groundwater contamination.
There are approximately 10 acres out of the total 49 acres of severe groundwater limitation, which limits the proper
absorption of effluent and leads to potential groundwater contamination. Over 91 percent of the area’s systems’ are
located on lots less than or equal to ½ acre. Less than one percent of properties were built before 1978. The small lot
sizes and existing developed parcels contribute to density of systems with approximately 68 systems greater than 2
per acre.
Based on qualifying criteria from the 2004 CWMP, together with the results of nitrogen loading documented in the
Madaket Harbor/Long Pond MEP, Warren’s Landing Needs Area qualifies as an area needing an off-site wastewater
disposal solution in this CWMP Update.
2.14.1.3 Somerset Needs Area
The Somerset Needs Area was evaluated in the 2004 CWMP and rated within the acceptable range to be
determined to be an area needing an off-site wastewater solution based on the existing criteria at that time. The
Needs Area does not have significant water resources within its boundaries with degradation issues and there is no
MEP Report supporting additional data. The area qualifies as a Need based on the 2004 CWMP data.
The Somerset Needs Area immediately abuts the Town sewer District to the southwest. The geographic area is a
predominantly residential area, with small, dense lot sizes.
The Needs Area encompasses approximately 196 acres, of which 181 are developed. There are 243 total parcels,
with 209 developed. There are 31 undeveloped residential parcels, with 30 potentially developable. There are 18
municipal/conservation parcels within this Needs Area. With few available developable parcels, sewering this Needs
Area does not promote any unwanted sprawl. The Needs Area is plagued with severe soils, over 84 percent
Evesboro Sands that are detailed by the United States Department of Agriculture Soils
Conservation Service as constrained as they percolate very fast and do not afford time in the soil layers to cleanse
before discharging into groundwater and thus travel fast to the Pond. The other predominant soil associations in this
Needs Area are Riverhead and Berryland Variant soils with qualities posing severity for on-site wastewater systems
highly permeable, depth to seasonal high groundwater and susceptibility to flooding. Evesboro Sands do not
adequately filter the effluent, which leads to groundwater contamination
There are approximately 7 acres out of the total 151 acres of severe groundwater limitation, which limits the proper
absorption of effluent and leads to potential groundwater contamination. The area is serviced by municipal water.
Over 67 percent of the area’s systems’ are located on lots less than or equal to ½ acres and approximately 7 percent
were built before 1978 (Creation of Title 5).
Based on qualifying criteria from the 2004 CWMP, Somerset Needs Area continues to qualify as an area needing an
off-site wastewater disposal solution in this 2013 CWMP Update.
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2.14.1.4 Monomoy Needs Area
The Monomoy Needs Area was evaluated in the 2004 CWMP and rated within the acceptable range to be
determined to be an area needing an off-site wastewater solution based on the existing criteria at that time. The 2004
CWMP did not have the advantage of years’ worth of water quality testing that is showing significant and rising
degradation to the Nantucket and Polpis Harbors since then. Monomoy Needs Area is fully within the Nantucket
Harbor Watershed and included in the Town’s Annual Water Quality Testing with records of testing/sampling results
from 2005 to present. This is one significant change since the 2004 CWMP, as water quality testing and results were
not available at that time. Since 2004, the Nantucket Harbor MEP Report has been completed and two TMDLs have
been issued by MassDEP, one in Nantucket Harbor and another in Polpis Harbor.
The Monomoy Needs Area immediately abuts Nantucket Harbor in the Town Basin. The Town Sewer District has
been extended into the Needs Area as delineated in 2004, thus new boundaries for this CWMP Update were drawn.
The upper portion of the 2004 area was cut off at Gardner Road and this is where the Shimmo Needs Area now
begins. The Monomoy and Shimmo Needs Areas differ slightly from the 2004 Report’s maps. The new delineations
were based on recommendations from Town officials, marine and costal resources, Natural Resources and Board of
Health that have historically worked on the Project. The new delineations more accurately capture Monomoy with
smaller, denser lots than Shimmo, which has larger lot sizes. These two Needs Areas have been the subjects of
model run scenarios completed for the Town by SMAST in order to arrive at solutions to meet the TMDLs in the
overall watershed. Refer to the previous section for additional information on the model runs scenarios completed as
part of the MEP.
The Needs Area encompasses approximately 391 acres, of which 303 are developed. There are 272 total parcels,
with 219 developed. There are 35 undeveloped parcels of which 25 are residentially developable in the future. There
are also 13 municipal/conservation parcels within this Needs Area. With few available developable parcels, sewering
this Needs Area does not promote any unwanted sprawl. The Needs Area is plagued with severe soils, over 90
percent Evesboro Sands that are detailed by the United States Department of Agriculture Soils Conservation Service
as constrained as they percolate very fast and do not afford time in the soil layers to cleanse before discharging into
groundwater and thus travel fast to the Pond. Properties of this soil association are highly permeable , depth to
seasonal high groundwater and susceptibility to flooding. Evesboro Sands do not adequately filter the effluent, which
leads to groundwater contamination. The other predominant soil association in this Needs Area is Riverhead Sandy
Loam, which is a moderately rapid permeable soil and does not provide sufficient filtering of effluent.
There are approximately 44 acres out of the total 391 acres of severe groundwater limitation, which limits the proper
absorption of effluent and leads to potential groundwater contamination. The majority of this Needs Area is serviced
with private water, thus posing additional threat from inadequately operating on-site wastewater disposal systems.
Approximately 9 percent of the area’s systems’ are located on lots less than or equal to ½ acres and over 35 percent
were built before 1978 (Creation of Title 5).
Based on qualifying criteria from the 2004 CWMP, together with the results of nitrogen loading documented in the
Nantucket Harbor MEP, Monomoy Needs Area qualifies as an area needing an off-site wastewater disposal solution
in this 2013 CWMP Update.
2.14.1.5 Shimmo Needs Area
The Shimmo Needs Area was evaluated in the 2004 CWMP and rated within the acceptable range to be determined
to be an area needing an off-site wastewater solution based on the existing criteria at that time. The 2004 CWMP did
not have the advantage of years’ worth of water quality testing that is showing significant and rising degradation to
the Nantucket and Polpis Harbors since then. Monomoy Needs Area is fully within the Nantucket Harbor Watershed
and included in the Town’s Annual Water Quality Testing with records of testing/sampling results from 2005 to
present. This is one significant change since the 2004 CWMP, as water quality testing and results were not available
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at that time. Since 2004, the Nantucket Harbor MEP Report has been completed and two TMDLs have been issued
by MassDEP, one in Nantucket Harbor and another in Polpis Harbor.
The Shimmo Needs Area immediately abuts Nantucket Harbor north of Monomoy and south of Polpis Harbor. The
lower portion of the 2004 area was amended to start at Gardner Road and this is where the Shimmo Needs Area
now begins. The Monomoy and Shimmo Needs Areas differ slightly from the 2004 Report’s maps. The new
delineations were based on recommendations from Town officials, marine and costal resources, Natural Resources
and Board of Health that have historically worked on the Project. The new delineations more accurately capture
Monomoy with smaller, denser lots than Shimmo, which has larger lot sizes. These two Needs Areas have been the
subjects of model run scenarios completed for the Town by SMAST in order to arrive at solutions to meet the TMDLs
in the overall watershed. Refer to the previous section for additional information on the model runs scenarios
completed as part of the MEP.
The Needs Area encompasses approximately 702 acres, of which 327 are developed. There are 203 total parcels,
with 106 developed. There are 27 undeveloped parcels of which 14 are potentially developable. There are over 70
municipal/conservation parcels within this Needs Area. With few available developable parcels, sewering this Needs
Area does not promote any unwanted sprawl. The Needs Area is plagued with severe soils, over 84 percent
Evesboro Sands/Plymouth-Evesboro series that are detailed by the United States Department of Agriculture Soils
Conservation Service as constrained as they percolate very fast and do not afford time in the soil layers to cleanse
before discharging into groundwater and thus travel fast to the Pond. Properties of this soil association are highly
permeable, depth to seasonal high groundwater and susceptibility to flooding. Evesboro Sands do not adequately
filter the effluent, which leads to groundwater contamination. The other predominant soil association in this Needs
Area is Pawtucket Muck and Berryland, which are very wet, mucky soils and not conducive to soil absorption fields.
There are approximately 175 acres out of the total 702 acres of severe groundwater limitation, which limits the proper
absorption of effluent and leads to potential groundwater contamination. The majority of this Needs Area is serviced
with private water, thus posing additional threat from inadequately operating on-site wastewater disposal systems.
Approximately 3 percent of the area’s systems’ are located on lots less than or equal to ½ acres and 17 percent were
built before 1978 (Creation of Title 5).
Based on qualifying criteria from the 2004 CWMP, together with the results of nitrogen loading documented in the
Nantucket Harbor MEP, Shimmo Needs Area qualifies as an area needing an off-site wastewater disposal solution in
this CWMP Update.
2.14.1.6 Hummock Pond North Study Area
The Hummock Pond North Needs Area was not evaluated separately in the 2004 CWMP - this is a new addition to
the CWMP Update based on the Hummock Pond MEP, which was started in spring of 2013 with and completed in
early 2014 with results now in draft form. The 2004 CWMP did not have the advantage of years’ worth of water
quality testing that is showing significant and rising degradation to the Pond since then, specifically Head of
Hummock. Hummock Pond was part of the original 89 embayments planned for study in the MEP, but was eliminated
during the program due to budgetary constraints. With years of results in the Town’s Annual Water Quality Testing
Program showing severe degradation, the Town pursued the MEP with supplemental funds raised locally in order to
get the study completed. The Town received the Draft Report in January 2014, showing results of 81 percent
degradation due to wastewater.
Since 2004, the Town has extended the Town Sewer District into portions of this Needs Area, which touches the
northern limits of the Hummock Pond Watershed as delineated and approved by the Town. Refer to Figure 2-X for a
map of this Needs Area.
Town of Nantucket (#225139.00)2-63 Woodard & Curran
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The Hummock Pond North Needs Area immediately abuts the Head of Hummock Pond, which is severely degraded
as detailed in the Hummock Pond MEP. Head of Hummock is detailed as supporting severely degraded habitat and
the focus of groundwater discharge to this portion of the Watershed and well beyond the threshold N level as
established for this Watershed.
The Needs Area encompasses approximately 962 acres, of which 426 are developed. There are 374 total parcels,
with 205 developed. There are 81 undeveloped parcels with 66 having potential for future development. There are
over 44 municipal/conservation parcels located within this needs Area. With few available developable parcels,
sewering this Needs Area does not promote any unwanted sprawl. The Needs Area is plagued with severe soils,
over 76 percent Evesboro Sands that are detailed by the United States Department of Agriculture Soils Conservation
Service as constrained as they percolate very fast and do not afford time in the soil layers to cleanse before
discharging into groundwater and thus travel fast to the Pond. Properties of this soil association are highly
permeable, depth to seasonal high groundwater and susceptibility to flooding. Evesboro Sands do not adequately
filter the effluent, which leads to groundwater contamination. The other predominant soil association in this Needs
Area is Berryland and Medisaprists, which are moderately rapid permeable, poorly drained soils and does not provide
sufficient filtering of effluent and have high water tables.
There are approximately 103 acres out of the total 962 acres of severe groundwater limitation, which limits the proper
absorption of effluent and leads to potential groundwater contamination. Over 39 percent of the area’s systems’ are
located on lots less than or equal to ½ acres and over 25 percent were built before 1978 (Creation of Title 5).
Based on current qualifying criteria, Hummock Pond North Needs Area qualifies as an area needing an off-site
wastewater disposal solution in this CWMP Update.
2.14.1.7 Hummock Pond South Needs Area
The Hummock Pond South Needs Area was evaluated in the 2004 CWMP (was the Cisco Needs Area in 2004) and
did not rate within the acceptable range to be determined to be an area needing an off-site wastewater solution
based on the existing criteria at that time. The 2004 CWMP did not have the advantage of years’ worth of water
quality testing that is showing significant and rising degradation to Hummock Pond since then. The Hummock Pond
South Needs Area immediately abuts the Hummock Pond’s eastern shoreline, which shows a gradient of degradation
based on the Pond areas. The upper level of the Pond abutting the Head of Hummock is severely degraded, the
middle portion is moderately degraded, while the lower levels of the Pond that immediately abut the shoreline show
degrading conditions, but not as significant as other portions of the Pond.
The Needs Area encompasses approximately 721 acres, of which 328 are developed. There are 358 total parcels,
with 282 developed. There are 41 undeveloped parcels with 21 having the potential for future development. There
are over 14 parcels either municipal, conservation or agricultural. With few available developable parcels, sewering
this Needs Area does not promote any unwanted sprawl. The Needs Area is plagued with severe soils, over 80
percent Evesboro Sands that are detailed by the United States Department of Agriculture Soils Conservation Service
as constrained as they percolate very fast and do not afford time in the soil layers to cleanse before discharging into
groundwater and thus travel fast to the Pond. Properties of this soil association are highly permeable, depth to
seasonal high groundwater and susceptibility to flooding. Evesboro Sands do not adequately filter the effluent, which
leads to groundwater contamination. The other predominant soil associations in this Needs Area are Riverhead-
Nantucket Complex, which is a moderately extremely slow permeable soil and Berryland, which does not provide
sufficient filtering of effluent.
There are approximately 56 acres out of the total 721 acres of severe groundwater limitation, which limits the proper
absorption of effluent and leads to potential groundwater contamination. The majority of this Needs Area is serviced
with private water, thus posing additional threat from inadequately operating on-site wastewater disposal systems.
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Over 24 percent of the area’s systems’ are located on lots less than or equal to ½ acres and over 32 percent were
built before 1978 (Creation of Title 5).
Based on current qualifying criteria, Hummock Pond South Needs Area qualifies as an area needing an off-site
wastewater disposal solution in this 2013 CWMP Update.
2.14.1.8 Miacomet Needs Area
The Miacomet Needs Area was evaluated in the 2004 CWMP and did not rate within the acceptable range to be
determined to be an area needing an off-site wastewater solution based on the existing criteria at that time. The 2004
CWMP did not have the advantage of years’ worth of water quality testing that is showing significant and rising
degradation to the Pond since then. While Miacomet Pond is not part of the Massachusetts Estuaries Program (MEP)
Studies as it is a freshwater body, the Pond does have a delineated watershed from the 1990 Water Resources
Protection Plan detailing the contributing areas to the watershed. Miacomet is included it in the Town’s Annual Water
Quality Testing with records of testing/sampling results from 2005 to present. This is one significant change since the
2004 CWMP, as water quality testing and results were not available at that time. In addition, the Pond has been
subject to severe flooding issues during storm events and the area generally is plagued with severe soil and
groundwater conditions. As of this Report writing, the Town is undertaking a major plan to evaluate Miacomet Pond
and the flooding and degradation issues that it is experiencing.
Also since 2004, the Town has extended the Town Sewer District into portions of the 2004 Miacomet Pond Study
Area, with this 2013 Area delineation being the remaining areas from 2004 that have not been sewered. This updated
delineation includes the major land area immediately abutting the Pond.
The Miacomet Needs Area immediately abuts Miacomet Pond to the west. According to the Town’s Annual Water
Quality Testing records from 2005 to present, Miacomet Pond is a closed coastal salt pond that is seldom (once in
the past ten years) opened to the ocean to flush out nutrients and organic matter on the ebb tide and receive saline
waters on the flood tide. The present non-tidal state and watershed nutrient inputs has resulted in a decline in
nutrient related water quality throughout the pond, with poor water quality conditions the present norm. All of the
water quality results show a consistency with a nutrient impaired basin. However, if the freshening of this basin
continues, it may come into a new equilibrium as a purely freshwater system and will need to be reassessed as such.
However, it will be difficult for Miacomet Pond to maintain itself as a purely freshwater system as storm overwash and
rising sea level will tend to periodically cause seawater intrusion into its lower basin.
In reviewing the water quality results from 2010 to present, the nutrient impairment from nitrogen and phosphorus
appear to be severe in the upper portions of the Pond (Station 3), middle portions of the Pond (Station 1) and fair in
the lower reaches (Station 2) abutting the ocean. As is discussed above, this is not a water resource that can be
opened to the open ocean for flushing due to its freshwater state, so solutions need to be arrived at looking at land
uses in the watershed-mainly wastewater, fertilizer and stormwater.
The Needs Area encompasses approximately 295 acres, of which 181 are developed. There are 124 total parcels,
with 102 developed. With few available developable parcels, sewering this Needs Area does not promote any
unwanted sprawl. The Needs Area is plagued with severe soils, over 84 percent Evesboro Sands that are detailed by
the United States Department of Agriculture Soils Conservation Service as constrained as they percolate very fast
and do not afford time in the soil layers to cleanse before discharging into groundwater and thus travel fast to the
Pond. Properties of this soil association are highly permeable, depth to seasonal high groundwater and susceptibility
to flooding. Evesboro Sands do not adequately filter the effluent, which leads to groundwater contamination. The
other predominant soil association in this Needs Area is Riverhead Sandy Loam, which is a moderately rapid
permeable soil and does not provide sufficient filtering of effluent.
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There are approximately 40 acres out of the total 295 acres of severe groundwater limitation, which limits the proper
absorption of effluent and leads to potential groundwater contamination. The majority of this Needs Area is serviced
with private water, thus posing additional threat from inadequately operating on-site wastewater disposal systems.
Over 25 percent of the area’s systems’ are located on lots less than or equal to ½ acres and over 28 percent were
built before 1978 (Creation of Title 5).
Based on qualifying criteria from the 2004 CWMP, Miacomet Needs Area qualifies as an area needing an off-site
wastewater disposal solution in this CWMP Update.
2.14.1.9 PLUS Needs Area
These parcels are various areas either within or directly abutting the Town Sewer District that for one reason or
another were left out of the Sewer District in error. Most are sandwiched within the existing sewer or are either at the
beginning or end of sewered streets. A complete review with the Town’s Planning Director and Director of Public
Works identified and approved these parcels to be included in the sewering plan moving forward. Most either
immediately abut infrastructure or are in close proximity of collection system components.
Sewering Priorities2.14.2
Based on the existing supporting data, this CWMP Update recommends the following sewering priorities:
Needs Area Priority Reasoning
Somerset This Needs Area needs to be completed first due to the
proposed route of bringing the highest Needs Areas
priorities-Madaket and Warrens Landing- to Surfside
WWTF. Hummock Pond North and South Needs Areas
are also proposed to flow through Somerset to the
Surfside WWTF.
Madaket and Warren’s Landing Needs Areas Established TMDL, Large number of documented Title 5
Technical failures (inability to meet groundwater
separation) contributing to nitrogen load through
groundwater resources and MEP Model detailing
removal of on-site wastewater meeting TMDL. Current
ACO Program area with Board of Health.
Monomoy Established TMDL and MEP Model detailing removal of
on-site wastewater meeting TMDL.
Shimmo Established TMDL and MEP Model detailing removal of
on-site wastewater meeting TMDL. Priority based on
Adaptive Management Plan and need for N reductions in
Harbor.
Hummock Pond North Pending TMDL and MEP Model detailing removal of on-
site wastewater meeting TMDL. May make sense to
sewer earlier in process as Madaket and Warrens
Landing will traverse through the area towards Somerset
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on way to Surfside WWTF.
Hummock Pond South Pending TMDL and MEP Model detailing removal of on-
site wastewater meeting TMDL. This Needs Area to be
prioritized based on Adaptive Management Planning
with breach and removal of Head of Hummock from
main body of Pond.
Miacomet Annual Water Quality Testing results depicting
degradation due to nutrient load from on-site systems.
Town Sewer District Infill and PLUS Parcels These areas can be serviced at any time as
infrastructure exists within close proximity. It is
recommended that these parcels be mandated to
connect under Local Regulation 69.00 in order to
reduce nitrogen loading in Nantucket Harbor
Watershed.
The 2004 Study Areas that have been re-evaluated based on the results of the MEP Reports include:
2004 Study Area MEP Area
Polpis Nantucket Harbor/Polpis Harbor
Pocomo Nantucket Harbor/Polpis Harbor
Wauwinet Nantucket Harbor/Polpis Harbor
Quidnet Sesachacha Pond
These 2004 Study Areas (Polpis, Pocomo, Wauwinet and Quidnet) were re-evaluated in this CWMP Update and
while not considered as areas needing an off-site wastewater solution in 2004 or 2013, they abut Nantucket Harbor in
various locations and contribute in various manners to the nitrogen loading documented in the MEP Report. Based
on additional studies completed by SMAST on scenarios in the Harbors to reduce nitrogen loading to meet
established TMDLS, sewering these areas did not serve to contribute to the reduction effort. It has been determined
that a more cost effective approach to the Nitrogen reduction be had through other contributors-fertilizer, stormwater
and future build out. These efforts will supplement the structured solutions being planned such as sewering, raising
the jetties to afford a deeper tidal exchange and dredging. This CWMP Update is making recommendations to limit
additional, future nitrogen loading with current and build-out conditions within the Adaptive Management Plan
contained herein.
These Study Areas are recommended for oversight under the Town’s Septage Management Plan. As part of the
overall Adaptive Management Plan include herein, this Report is also recommends consideration for future
management utilizing Innovative / Alternative systems due to each area’s geographic locations within Nitrogen-
sensitive embayments as detailed in the MEP Reports. I/A systems will afford a higher nutrient reduction, up to 50
percent of TN, than a conventional Title 5 system is able to do. Each Study Area is delineated in this CWMP Update
on Figure 2-21, which follows this section.
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The Town is working with Barnstable County on a cooperative program to maintain all Innovative and Alternative (I/A)
Wastewater Systems. This is a win/win for both entities as Nantucket will maintain jurisdiction over the approval of
systems, but Barnstable County Department of Health will become the operation and maintenance jurisdiction.
Barnstable now manages all I/A systems Cape-wide with a comprehensive database that tracks all systems, their
repair records, as well as their performance standards in nutrient reduction capabilities. Adding Nantucket’s I/A
systems to the data set will afford a wider and more comprehensive record set for use by all. Barnstable is currently
updating its database hardware and once completed, Nantucket will join forces with this cooperative program.
The Town, under the auspices of the local Septage Management Plan, as well as Barnstable County, will be able to
monitor all on-site wastewater disposal systems, both conventional and I/A in order to evaluate future needs based
on water quality results. This will aid the Town in determining the overall need to develop a new Local Regulation
prescribing the use of Innovative / Alternative systems in Nitrogen-sensitive areas as so defined in the CWMP
Update.
2.14.2.1 Polpis
The Polpis Study Area was evaluated in the 2004 CWMP and recommended to maintain on-site wastewater disposal
under the Town’s Septage Management Plan unless the MEP report being completed at the time of the 2004 Report
recommended otherwise (The 2004 CMP was completed before the MEP Study was finished). This CWMP Update
maintains this determination with a few exceptions based on the results of the Nantucket and Polpis Harbors MEP.
Because Polpis Harbor is included as part of the overall Nantucket Harbor MEP with two TMDLs established in the
Harbor areas (Nantucket Harbor and Polpis Harbor) and with a threshold water quality to meet, it is suggested that
future build out in this geographic area, defined as the Polpis Study Area in the CWMP Update, as well as future
repairs and/or upgrades to current Title 5 systems be endorsed with an I/A system in order to reduce Nitrogen
loading to the Watershed. The Polpis Study Area is a high priority in terms of requiring attention due its location in
proximity to and potential impact to not only Polpis Harbor, but also Nantucket Harbor from the existing conventional
on-site wastewater disposal systems.
2.14.2.2 Pocomo
The Pocomo Study Area was evaluated in the 2004 CWMP and recommended to maintain on-site wastewater
disposal under the Town’s Septage Management Plan unless the MEP report being completed at the time of the
2004 Report recommended otherwise (The 2004 CMP was completed before the MEP Study was finished). This
CWMP Update maintains this determination with a few exceptions based on the results of the Nantucket and Polpis
Harbors MEP. Due to two TMDLs established in this geographic area as a result of the completed Nantucket and
Polpis Harbor MEP and the location of this Study Area in the upper reaches of the Harbor, it is necessary to look
towards future build out conditions with respect to nutrient loading. There are two TMDLs established in this area,
one in Nantucket Harbor and the second in Polpis Harbor. In order to meet and maintain the established threshold
water quality, it is suggested that future build out in this geographic area, defined and delineated as the Polpis Study
Area in the CWMP Update, as well as future repairs and/or upgrades to current Title 5 systems be endorsed based
on Adaptive Management Planning results utilizing I/A systems in order to reduce Nitrogen loading to the Watershed.
The Pocomo Study Area is a high priority in terms of requiring attention due its location in proximity to and potential
impact to not only Polpis Harbor, but also Nantucket Harbor from the existing conventional on-site wastewater
disposal systems.
2.14.2.3 Wauwinet
The Wauwinet Study Area was evaluated in the 2004 CWMP and recommended to maintain on-site wastewater
disposal under the Town’s Septage Management Plan unless the MEP report being completed at the time of the
2004 Report recommended otherwise (The 2004 CMP was completed before the MEP Study was finished). This
CWMP Update maintains this determination with a few exceptions based on the results of the Nantucket and Polpis
Town of Nantucket (#225139.00)2-68 Woodard & Curran
Final CWMP Update Report Volume I October 2014
Harbors MEP. Due to two TMDLs established in this geographic area as a result of the completed Nantucket and
Polpis Harbor MEP and the location of this Study area in the upper reaches of the Harbor, it is necessary to look
towards future build out conditions with respect to limiting additional nutrient loading. There are two TMDLs
established in this area, one in Nantucket Harbor and the second in Polpis Harbor. In order to meet and maintain the
established threshold water quality, it is suggested that future build out in this geographic area, defined and
delineated as the Polpis Study Area in the CWMP Update, as well as future repairs and/or upgrades to current Title 5
systems, be endorsed based on Adaptive Management Planning results utilizing I/A systems in order to reduce
Nitrogen loading to the Watershed. The Wauwinet Study Area is a high priority in terms of requiring attention due its
location in proximity to and potential impact to not only Polpis Harbor, but also Nantucket Harbor from the existing
conventional on-site wastewater disposal systems.
2.14.2.4 Quidnet
The Quidnet Study Area was evaluated in the 2004 CWMP and recommended to maintain on-site wastewater
disposal under the Town’s Septage Management Plan unless the MEP report being completed at the time of the
2004 Report recommended otherwise (The 2004 CMP was completed before the MEP Study was finished). This
CWMP Update maintains this determination with a few exceptions based on the results of the Sesachacha Pond
MEP. Due to the threshold TMDLs established in this geographic area as a result of the completed MEP and the
location of this Study Area in the overall Pond watershed, it is necessary to look towards future build out conditions
with respect to limiting additional nutrient loading. It is recommended that the Town monitor the future results of the
bi-annual breaches of the Pond, which are currently meeting the established threshold in the Pond. If at some point in
the future it is, determined additional build-out is occurring in the Watershed, water quality monitoring should
determine the need for additional nutrient reduction utilizing I/A systems. With this in mind and in order to meet and
maintain the threshold water quality, it is suggested that future build out in this geographic area defined and
delineated as the Quidnet Study Area in the CWMP Update, as well as future repairs and/or upgrades to current Title
5 systems be endorsed with an I/A system in order to reduce Nitrogen loading to the Watershed should the need
arise.
Figure 2-20 details the Final recommended Plan for both Needs and Study Areas. Table 2-12 details the updated
Matrix for areas not noted as Needs Areas in the 2004 CWMP/EIR, but now meeting criteria as a Needs Area.
’ . $0 R 0# . 1 )'04
’ " (# 0 . ,. 0# ./&# "
COMPREHENSIVE WATER RESOURCE MANAGEMENT PLAN UPDATE
TOWN OF NANTUCKET, MASSACHUSETTS
RATING CRITERIA
FIGURE 2-22
Hummock Pond North Hummock Pond South Miacomet
CRITERIA NAME DESCRIPTION 1 2 3
Number Points Number Points Number Points
CRITERIA POINTS Total Number of Lots 374 358 124
Actual Failure 4 Total Number of Developed Lots 205 282 102
Imminent Failure 3 Total Number of Unsewered Developed Lots 205 282 102
High Likelihood of Imminent Failure 2 Number of Resales since 3/31/95 146 218 81
Health / Water Quality Issue 1 Number of Acres per Study Area 962 721 295
Number of Net Acres for Developed Lots 426 328 181
No. of Acres of Severe Groundwater Limitation 103 56 40
Number of Acres of Severe Soil Limitation 575 146 324 326
Actual Failure 2004 to July 2012 5 20 5 20 4 16
0 0 0
5 20 5 20 4 16
Adjusted Total based on Developed/Unsewered Developed Ratio 20 20 16
Imminent Failure System within Zone I Aquifer Recharge Area 0 0 0 0 0 0
System within 50 feet of Private Drinking Water Well 120 360 197 591 85 255
System within 100 feet of Public Drinking Water Supply 0 0 0 0 0 0
Developed Lots with Less than 10,000 sq. ft. of area per Bedroom1 0 0 0 0 0 0
120 360 197 591 85 255
High Likelihood of Imminent Failure Lots with Severe Groundwater Limitation 22 44 22 22 44 22 14 28 14
Systems Built before 1978 (Title 5)51 102 91 182 51 102
Lot Size less than or equal to 1/2 acre 79 158 69 138 45 90
Lots with Severe Soil Limitation 123 246 123 127 254 127 113 226 113
Pumpouts Greater than 2 times per year 0 0 0 0 0 0
275 550 309 618 223 446
Health / Water Quality Issue Density of Systems Greater Than 2 per Acre1 0 0 0 0 0 0 0 0 0
System within 100 feet of Surface Water Body, Wetlands or Streams 38 38 18 18 6 6
System located within 100 Year Flood Plain 1 1 16 16 0 0
System within Zone II Aquifer Recharge Area 4 4 0 0 0 0
Needs Area Within MEP 1 1 0
TMDL Pending 1 1 1 1 0 0
Systems within Approved Harbor Watershed Delineation 205 31 31 0 0
250 250 67 67 6 6
Total Criteria Points for Study Area 1,180 1,296 723
Rating Criteria Points Per Developed Lot 5.76 4.60 7.09
YES YES YES
RECOMMENDED AS A NEED AREA YES YES YES
(Conventional Title 5 System Not Feasible for Majority of Study Area)
1 Incomplete data in Town data to calculate
Town of Nantucket (#225139.00)2-71 Woodard & Curran
Final CWMP Update Report Volume I October 2014
Wastewater Flow and Loads Update2.14.3
In order to update the assessment of the Town’s wastewater disposal needs and recommend appropriate wastewater
disposal solutions for each Need Area and Study Area, W&C estimated the wastewater flows and waste loads that
would be generated in the Areas. A key component of these updates was reflecting the revised zoning and extent of
the Town Sewer Districts.
A defined methodology was utilized to calculate these estimates as described below.
W&C revised the flows and loads for the Need and Study Areas by updating counts of developed and undeveloped
residential and commercial parcels in each Area, and verifying land use, zoning, and sewer status for each parcel
using the Town’s Assessor’s Database, State Land Use Codes, and the Town’s Sewer Districts, sewer users, and
zoning mapping in GIS.
After these updates were made, we assigned the following rules to parcels:
All developed single-family residential parcels were assumed to have at least one wastewater connection.
All developable or potentially developable residential parcels that met zoning were assumed to have at least
one wastewater connection.
We assumed any parcel that meets zoning could have a second dwelling. For example, single-family
residential parcels that met zoning were assumed to have two wastewater connections. However, based on
discussions with the Town Planner and the fact that approximately only 12% of residences on the island
currently have second dwellings, overall to be conservative we assumed only 25% of the second dwellings
could be built.
All developed commercial parcels were assigned a flow based on acreage.
Developable and potentially developable commercial parcels that met zoning were also assigned a
wastewater flow based on acreage.
Based on discussions with Nantucket Assessor, we assumed all multi-family parcels in the Areas are equal
to two residential wastewater connections.
Average Daily Flow estimates for both summer and winter were developed using the above described parcel count
methods and applying the unit flows consistent with the previous CWMP work. In the Phase I CWMP, wastewater
flows from 1999 at the Surfside Wastewater Treatment Facility were analyzed in conjunction with the number of
residential and commercial units connected to the system to estimate unit wastewater flows. Population data were
used to determine the average number of people per residential household. Table 2-13 presents the results of this
analysis from the Phase I CWMP. These values were used in wastewater flow calculations for this CWMP update.
Table 2-13: Phase I CWMP Wastewater Winter and Summer Wastewater Unit Flows
Season
Average Number
of People per
Household
Gallons per
Capita Per Day
Residential
Wastewater
Flow (GPD)
Commercial
Wastewater Flow
(GPD)
Summer
(June – September)4.5 71.1 320 345
Winter
(December – March)2.5 74 185 260
Note that wastewater is typically composed of residential, commercial and industrial sources. As was the case in both
the Phase I CWMP and the 2004 CWMP/EIR, industrial sources continue to be absent in Nantucket and therefore to
Town of Nantucket (#225139.00)2-72 Woodard & Curran
Final CWMP Update Report Volume I October 2014
be representative of current conditions and consistent with these reports, only residential and commercial flows are
developed for this update.
Infiltration and inflow (I/I) was estimated assuming 250 gallons per day-inch-mile (gpdim) for new pipe in accordance
with MassDEP I/I standards. Infiltration/inflow was not estimated for any low pressure sewer. The length of gravity
sewer in Somerset presented in the 2004 CWMP was included in these calculations. The 2004 CWMP identified
Madaket and Warrens Landing as being sewered with 100% low pressure. For the remaining Areas, to determine the
total length of sewer, the approximate length of streets within each area was extracted from GIS mapping.
To be consistent with the Phase I CWMP, wastewater loads were calculated by applying industry standard factors
from the New England Interstate Water Pollution Control Commission Guides for the Design of Wastewater
Treatment Works (TR-16) and from Table 3-15 of Wastewater Engineer Treatment and Reuse, 4th Edition, by
Metcalf & Eddy, to the estimated average daily wastewater flows. Table 2-14 presents a summary of the wastewater
load factors.
Table 2-14: Wastewater Load Factors
Parameter
Residential
(lbs/capita/day)
Commercial/Industrial
(mg/L)
BOD 0.22 250
TSS 0.25 300
Total Nitrogen 0.04 40
In the Phase I CWMP, “Peak Hourly Flow” and “Maximum Daily Flow” were estimated using peaking factors from TR-
16. However, for this CWMP update, to better represent actual conditions experienced at the WWTF, ratios from
existing treatment plant data were utilized to estimate maximum month, maximum day, and peak hourly flows, as well
as the maximum month loads. Table 2-15 shows these ratios.
Table 2-15: Wastewater Flow and Load Ratios Based on Existing WWTF Data
Parameter Ratio
Max Month Flow 1.07
Max Day Flow 1.37
Peak Hourly Flow 2.65
BOD Max Month 1.17
TSS Max Month 1.32
TN Max Month 1.15
Detailed calculations are included in Appendix F and a summary of the wastewater flow and loading estimates are
presented in Table 2-16.
Town of Nantucket (#225139.00)2-73 Woodard & Curran
Final CWMP Update Report Volume I October 2014
Table 2-16: Average Daily Flow and Peak Hour Flow
Flow
(MGD)
BOD5 Load
(lbs/day)
TSS Load
(lbs/day)
Total Nitrogen
Load (lbs/day)
Average
Daily -
Summer
Maximum
Monthly
Maximum
Daily
Peak
Hourly
Average
Daily
Maximum
Monthly
Average
Daily
Maximum
Monthly Average Daily
Maximum
Monthly
Projected by Study / Need Area
Madaket 0.16 490 560 90
Warren's Landing 0.03 100 110 20
Hummock Pond South 0.07 200 230 40
Hummock Pond North 0.09 290 330 50
Somerset 0.10 320 360 60
Monomoy 0.08 260 300 50
Shimmo 0.06 190 220 30
Town 0.59 1,800 2,050 330
Nantucket PLUS 0.07 230 260 40
Miacomet 0.07 210 240 40
Subtotal Projected 1.33 1.42 1.82 3.52 4,090 4,660 750
Projected Infiltration/Inflow (Future)0.06 0.06 0.06 0.06
Total Projected 1.39 1.48 1.88 3.58 4,090 4,790 4,660 6,150 750 860
Existing Conditions at Surfside WWTF 1.53 1.64 2.10 4.06 4,990 5,830 3,490 4,610 530 610
Total Projected and Existing (Future Conditions) 2.9 3.1 4.0 7.7 9,100 10,600 8,200 10,800 1,300 1,500
Town of Nantucket (#225139.00)3-1 Woodard & Curran
Final CWMP Update Report Volume I October 2014
3.ALTERNATIVES DISCUSSION
3.1 SUMMARY AND UPDATE OF 2004 CWMP ALTERNATIVES
A variety of wastewater alternatives were investigated during the Phase III CWMP/FEIR in 2004 to determine the
appropriate wastewater facilities that will meet the needs of Nantucket. The wastewater alternatives that were
investigated include:
(a) the continued use of existing on-site wastewater disposal systems;
(b) replacement of existing wastewater disposal systems with Title 5 systems;
(c) replacement of existing wastewater disposal systems with on-site innovative/alternative options;
(d) replacement of existing wastewater disposal systems with cluster systems consisting of a pressure system
and communal subsurface disposal; and
(e) replacement of existing wastewater disposal systems with a conventional sewer collection system, either:
(1) connection into the existing collection system;
(2) gravity sewers and pump station,
(3) pressure sewers and grinder pumps, or
(4) a combination thereof.
Each wastewater alternative was evaluated based on environmental and technical design criteria and on site-specific
data such as subsurface conditions, topography, and existing septic system performance. The 2004 CWMP
evaluated the environmental, technical design and institutional cost associated with each alternative and
recommends the appropriate solution to the wastewater disposal problems for the Town of Nantucket in order to
reach a long-term solution to the wastewater needs of the Island. Alternatives evaluated included:
Repair / Upgrade Existing On-Site Systems
Upgrade to Conventional Title 5 System
Decentralized Facilities
Small Cluster Systems
Innovative/Alternative systems
Optimizing the performance of the existing on-site wastewater disposal systems is not conducive in many areas on
Island due to a number of reasons. The most difficult condition to overcome is subsurface conditions including
shallow depth to groundwater and insufficient depth of naturally occurring pervious soil. This is evident in many areas
where the groundwater poses issues with meeting current Title 5 standards with a four foot separation, but is further
constrained due to the Board of Health’s more stringent limits of five to six foot separations. These more stringent
separations are necessary to provide additional wastewater time in fast percolating soils before reaching
groundwater resources, but are responsible for a great number of “technical” failures of on-site systems. Variances to
these limits will only serve to continue to degrade the environment, specifically the water resources/embayment
areas, which the recommendations in this Report are attempting to preserve and protect.
Town of Nantucket (#225139.00)3-2 Woodard & Curran
Final CWMP Update Report Volume I October 2014
Based on historical data, 2004 criteria and the updates within this Report, the following areas have been identified as
needing an off-site wastewater solution; 1) Madaket; 2) Warren’s Landing; 3) Hummock Pond North; 4) Hummock
Pond South; 5) Somerset; 6) Miacomet; 7) Monomoy; 8) Shimmo; and 8) the remainder of parcels within the Town
Sewer District currently not sewered.
The remainder of the Town can remain on on-site wastewater disposal systems with specific areas being
recommended for on-site Innovative / Alternatives systems. Those areas include 1) Polpis; 2) Pocomo; and 3)
Wauwinet due to their being within the Nantucket Harbor watershed, which is identified in the MEP as a Nitrogen
Sensitive Area.
A cost comparison of a multitude of wastewater systems was completed by the Barnstable County Wastewater Task
Force for Cape Cod that are applicable to Nantucket. A “Comparison of Costs for Wastewater Management Systems
Applicable to Cape Cod, Guidance to Cape Cod Towns Undertaking Comprehensive Wastewater Management
Planning” is the most up to date resource for capital costs, operation and maintenance costs, equivalent annual costs
and costs per pound of nitrogen removed for individual on-lot wastewater systems, cluster systems, satellite systems
and new centralized systems. We had multiple discussions with the Director of Barnstable County Health regarding
the various alternatives available for wastewater use. Nantucket Board of Health is in regular communication with
Barnstable with regards to on-site wastewater items.
The complete report can be accessed on the Cape Cod Water Protection Collaborative website at;
http://www.ccwpc.org/index.php/component/content/article/36-wastewater-reports/78-comparison-of-costs-for-
wastewater-management-systems-applicable-to-cape-cod.
There have been multiple discussions with the Board of Health (BOH) regarding on-site systems and their ability to
meet Local Regulations as adopted by the BOH. There are multiple areas where the BOH has determined I/A
systems are the recommended alternative due to their ability to meet more stringent requirements than a Title 5
system. For example, an I/A system reduces nitrogen 50 percent more than a standard Title 5 on-site system. Areas
where the BOH has mandated use of these systems include areas where depth to groundwater cannot be attained,
proximity to water bodies and other various reasons.
The I/A of choice for use by Nantucket BOH has been the Septitech System, which the Board of Health identifies as
a system that meets its documented specifications for nutrient reduction and is a system that has a reliable operating
and maintenance record. Barnstable County Health Department maintains a database of all I/A systems in use Cape-
wide with records of number of systems in use, length of use and records of test results. Nantucket BOH is working
with Barnstable for future coordination in Barnstable taking over management of its I/A systems. This will provide
benefit to both Barnstable County and Nantucket, with the former having additional data for its database and the
latter by turning all management operations of I/A systems over to Barnstable, which alleviates this task from already
short staff.
This database can be accessed at http://www.barnstablecountyhealth.org/.
3.2 RE-EVALUATION OF WWTF OPTIONS – ELIMINATION OF PROPOSED MADAKET WWTF
One of the major, if not the most noted, recommendations in the 2004 CWMP was the proposal to design and
construct a new satellite WWTF located at the former FAA site in Madaket to service the Madaket and Warren’s
Landing Needs Areas. This proposed recommendation to design and construct a WWTF on the former FAA site on
Red Barn Road in Madaket brought a cost that exceeds $80M in today’s dollars, as well as a host of environmental
issues to overcome/mitigate with regards to land uses both under the Massachusetts Historical Commission (MHC)
and the Natural Heritage and Endangered Species Program (NHESP).
Town of Nantucket (#225139.00)3-3 Woodard & Curran
Final CWMP Update Report Volume I October 2014
The Town has been working with the General Services Administration (GSA) of the Federal Government since early
2000 regarding the initial decommissioning of the FAA parcel due to new technology and current disposing of the
land under the jurisdiction of the GSA. As part of the Town’s due diligence, and required under the 2004
Massachusetts Environmental Policy Act (MEPA) Office Certificate No. 12617, intensive surveys for both MHC and
NHESP were mandated before the Town could move forward with any planning, design or construction. Under
Permit with NHESP, an Inventory was performed between May 14 and September 11, 2011 to complete a habitat
assessment on the former FAA parcel. The entire 91.71 acre site was surveyed in this effort. In February 2012, the
“FAA Property Habitat Assessment and Rare Plant Species Inventory” Report was finalized and filed with NHESP.
Significant habitat was identified and located on the site that presents severe limitations to its use and will require at
least a 2 to 1 mitigation if the Town was to move forward with the WWTF planning. Refer to Appendix G for copies of
the NHESP information.
Under Permit #3253 from MHC, an Intensive Survey was commenced in summer of 2013 on the 25-acre portion of
the 91.71 acre site proposed for the WWTF location. An Archaeological Resources Protection Act Permit was also
filed before conducting the Intensive Survey. As part of this process, a permit was required for oversight by a botanist
from the NHESP in order to preserve and protect the resources identified in the NHESP Inventory that took place
prior to the MHC Survey. The results of the Intensive Survey did not disclose any significant historical and/or
archaeological resources on the 25-acre portion. It is important to note that the remaining 66.71 acres were not
evaluated and so no determination as to the historical/archaeological relevance can be arrived at in these areas.
Refer to Appendix G for MHC data and correspondence.
Based on cost consideration, environmental concerns and overall Island sentiment to building a third WWTF on
Island, and after the above due diligence was completed, the Town asked that alternatives be re-evaluated for this
geographical area in the CWMP Update. Because the Madaket and Warren’s Landing Needs Areas are the subject
of the Madaket Harbor/Long Pond MEP with a recommendation to remove wastewater from the Watershed in order
to meet the Draft TMDL, a solution for wastewater management is a necessity. The Town requested that a thorough
review of the existing Surfside WWTF be completed in order to determine if this was an option for Madaket and
Warrens Landing Needs Areas. A Capacity Analysis was initiated at the existing Surfside WWTF to determine first
what flows are now being collected, treated and discharged at this location, as well as what future flows and ,loads
could be handled by the WWTF under existing conditions. In addition to the facility capacity analysis, a
hydrogeological evaluation was completed in order to determine the capacity for discharge at the 15 existing sand
beds that service the Surfside WWTF. It was determined that the Surfside WWTF was designed to handle the
additional flow, but the Groundwater Discharge Permit was the limiting factor as it was for 3.5 MGD, which is less
than the WWTF design flow.
Discussion was opened with MassDEP as to how the Town could modify the current Surfside Groundwater
Discharge Permit SE #1-200 to accommodate all the identified Needs Areas and it was concluded that it was
possible based on the Hydrogeological Evaluation completed at the site detailing that the existing beds could handle
a higher discharge flow, from 5 gallons per square foot per day to 6 gallons per square foot per day. After multiple
meetings with MassDEP and a Technical Memorandum, dated December 2013 detailing the agreed upon plan to
modify the existing Groundwater Discharge Permit, the Town filed both BRP WP 11 – Individual Permit
Renewal/Modification With Plan Approval and BRP WP 83 – Hydrogeological Evaluation. The Town has received
verbal approval to the modification. MassDEP is in the process of reissuing the Groundwater Discharge Permit,
which was due to be renewed in 2015. Copies of all correspondence and filings are included in Appendix H.
3.3 SURFSIDE WASTEWATER TREATMENT FACILITY RECOMMENDED IMPROVEMENTS
This section describes the improvements Woodard & Curran is recommending for the Surfside Wastewater
Treatment Facility (WWTF). We prepared estimated conceptual level project capital costs for these improvements
Town of Nantucket (#225139.00)3-4 Woodard & Curran
Final CWMP Update Report Volume I October 2014
and the recommended schedule for these improvements is included in the capital improvement plan section of this
report. We have organized the recommended improvements into the following categories:
Improvements for future capacity needs
Improvements for reliability
Improvements for energy efficiency
3.4 IMPROVEMENTS FOR FUTURE CAPACITY
As part of our contract with the Town for Madaket Wastewater Planning, Woodard & Curran performed a capacity
evaluation of the Surfside WWTF to determine the feasibility of accepting the projected flows and loads from the
Madaket and Warren’s Landing Needs Areas. The evaluation included an assessment of existing and projected
wastewater flows and loads, an assessment of current WWTF performance, and a determination of required
improvements. A detailed description of our capacity analysis is provided in Appendix H.
The findings of our capacity assessment were as follows:
The future condition is a maximum daily flow of 4.0 million gallons per day (MGD) which includes build out of
the existing sewer areas and sewer extension to the needs areas.
The Surfside WWTF has sufficient capacity to receive wastewater at the future condition provided that minor
changes are made to operational practices and additional aeration blower capacity is provided.
Although the Surfside WWTF has capacity, the future maximum daily flow of 4.0 MGD exceeds the Town’s
MassDEP Groundwater Discharge Permit limit of 3.5 MGD for daily flow to the groundwater discharge beds.
Therefore, expansion of the groundwater discharge capacity or revisions to the groundwater discharge
permit are required.
Expansion of groundwater discharge capacity or revisions to the Groundwater Discharge Permit would be
required at the future condition even if Madaket and Warren’s Landing wastewater was not treated at the
Surfside WWTF.
The recommended improvements to the Surfside WWTF for future capacity include additional aeration blowers and
modifications to the nitrate recycle system as follows:
Additional Aeration Blowers3.4.1
The Surfside WWTF existing aeration system includes three Aerzen positive displacement blowers, each with a
design capacity of 950 standard cubic feet per minute. Based on our calculations for oxygen requirements, we
determined that the existing aeration tank blowers do not have enough capacity for the future condition, therefore two
additional blowers are needed (one to provide the additional capacity required and one to serve as a redundant
backup). With this additional blower capacity, there is sufficient capacity for the flow and loads at the future condition.
Modifications to the Nitrate Recycle3.4.2
During our evaluation, WWTF operations staff expressed concerns with having the ability to denitrify at the future
condition because of the anoxic tank volume and because nitrate recycle from the membrane tanks may have a high
dissolved oxygen (DO) concentration ,which could inhibit denitrification. Our calculations (as well as the original GE
Zenon design calculations) and the plant data that we have been provided indicate that these two items would not be
a problem. However, there are many variables that can affect the actual results. Therefore, to address this concern,
we recommend gathering additional nitrate data and monitoring the results as flows and loads to the Surfside WWTF
Town of Nantucket (#225139.00)3-5 Woodard & Curran
Final CWMP Update Report Volume I October 2014
increase in the future. We also have prepared a conceptual layout and conceptual cost estimate for improvements to
the nitrate recycle system in case future problems are encountered. The improvements include modifying the existing
recycle from the membrane tanks with redirection to the aeration tanks and an additional, separate, nitrate recycle
from end of the aeration tanks to the anoxic tanks.
3.5 IMPROVEMENTS FOR RELIABILITY
We have identified and recommend several improvements to increase the reliability and long-term effectiveness of
operation of the Surfside WWTF. Some of the improvements for reliability were identified and evaluated as part of our
contract with the Town for the Alternatives Analysis, Recommendations and Conceptual Opinion of Probable Cost of
Proposed Upgrades to the Surfside WWTF and some the improvements were identified through the Surfside WWTF
capacity assessment.
Corrosion Control3.5.1
The Surfside WWTF has experienced severe corrosion of the concrete and metal components at the headworks, and
there was concern that corrosion may have been occurring at other locations such as the primary clarifiers. The
corrosion is due to the presence of hydrogen sulfide, which is formed upstream in the collection system, particularly
in the force mains.
To address this concern, Woodard & Curran engaged a specialty sub-consultant, Bowker & Associates (Bowker), to
perform a sampling program, assess the corrosion, identify alternatives for addressing the situation, and provide a
recommended solution with opinion of probable construction cost. The Bowker study found severe hydrogen sulfide
corrosion at the headworks of the Surfside Wastewater Treatment Facility and recommended an oxygen injection
system, installed at the Sea Street Pump Station, for mitigation.
Woodard & Curran reviewed the Bowker Report and agrees with these findings and recommendations. The
recommended oxygen injection system has a higher capital cost than the other alternatives, however it has the
lowest life-cycle cost because it does not require the purchase of chemicals which are quite costly. A detailed
description of the Bowker corrosion control study is provided in the appendices of the full report that is included in
Appendix H.
Influent Screening3.5.2
An influent grinder was installed at the Surfside WWTF during the 2009 upgrade, however due to severe hydrogen
sulfide corrosion; the grinder is no longer functional and was removed. To evaluate this issue, a screening analysis
was conducted and documented in a memorandum entitled “Enhancements to the Surfside Wastewater Treatment
Facility” by AECOM, dated January 9, 2012. The memorandum outlined the importance of MBR system
pretreatment, identified pretreatment alternatives, and ultimately recommended the installation of a grinder in the
headworks to breakdown influent debris. A copy of this memorandum is included in Appendix H.
The Town was interested in receiving a second opinion regarding the need for membrane pretreatment (screen
versus grinder) and contracted Woodard & Curran to provide an Influent Screening Alternatives Assessment. A
detailed description of our influent screening alternatives analysis is provided in the full report, which included the
following tasks:
Review existing documentation related to influent screening including design plans, operation and
maintenance manuals, plant hydraulics, and the AECOM Memorandum dated January 9, 2012.
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Identify feasible screening alternatives and/or combinations of alternatives suitable for a membrane
bioreactor treatment facility with primary clarifiers with the Surfside WWTF specific hydraulic and spatial
requirements and operational needs.
Provide a recommendation of the most desirable screening alternative with consideration given to process,
cost, operation and maintenance concerns.
Provide an opinion of probable cost for the recommended alternative including design, construction,
engineering and contingency suitable for securing funding.
After analysis of multiple alternatives, we recommend the installation of a new headworks consisting of two 6-mm
screens, two 2-mm band screens, and two wash presses for screenings handling. We also recommend that a new
vortex grit removal system is incorporated into the new headworks to address issues with existing corrosion and grit
equipment at the existing aerated grit chamber. We also recommend that this equipment is housed within a cedar
shingled building.
Vactor Truck Unloading3.5.3
Currently, the vactor truck discharges directly into the primary settling tanks (PST). This means of discharging is not
ideal because the contents are not screened and bypass the grit removal processes, likely disrupting settling in the
PSTs. Woodard & Curran analyzed installing a vactor unloading station at the Surfside WWTF. Multiple locations and
options were considered for the vactor discharge station, including the recommendations described in the previous
memorandum entitled “Enhancements to the Surfside Wastewater Treatment Facility” by AECOM, dated January 9,
2012.
Based on our evaluation we recommend the installation of a concrete ramp adjacent to the proposed new
headworks. Catch basins would be installed at the bottom of the ramp. The vactor truck would back to the edge of
the concrete ramp and discharge its contents at the bottom of the ramp. The catch basins would allow for the liquid to
discharge through to the headworks and simultaneously prevent debris and objects from passing through. The
screened contents would then be removed with a loader truck and discharged into a dump truck, which would be
hauled to a disposal site.
Aeration Tank Instrumentation3.5.4
Surfside operations staff reported that the dissolved oxygen control instrumentation is not reliable and cannot be
utilized for aeration tank blower control as was the original design intent. Replacement of these instruments with
more reliable DO and oxidation reduction potential (ORP) measurement capability would enhance the ability to
operate the WWTF at the future condition.
Primary Sludge Pump Replacement3.5.5
There are three existing primary sludge pumps that were installed during the 1992 upgrades. Given the age of these
pumps we anticipate that these pumps will need to be replaced within the 20-year planning period of this Report.
Membrane Removal Equipment3.5.6
Periodic removal and inspection of the membrane cassettes is recommended by the membrane manufacturer
(General Electric/Zenon). The Surfside WWTF does not currently have the equipment needed to remove the
membrane cassettes. When inspections have been done in the past, the Town is forced to rent a crane, which is a
costly option. We recommend installation of 6-ton rated travelling monorail crane and hoist to better facilitate regular
Town of Nantucket (#225139.00)3-7 Woodard & Curran
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inspection of the membranes. This equipment would also allow operations staff to make minor repairs to the
membranes as needed.
Membrane Inspection and Replacement3.5.7
The ability to predict the expected life of membranes is very limited because membrane treatment for municipal
wastewater is a relatively new application. In addition, the characteristics of the influent wastewater, the treatment
process conditions, and the associated membrane fouling constituents can vary greatly among WWTFs. It is our
general understanding that the expected membrane life will be less than the 20-year planning period of this Report.
Based on correspondence with General Electric (GE)/Zenon, we understand that, as part of the terms of the original
membrane purchase, the Town has an agreement with GE/Zenon that membranes purchased before the 10-year
anniversary (approximately December of 2018) of the membrane installation may be purchased at a discount. The
discounted replacement price is established using a base price adjusted for inflation using the Consumer Price Index.
According to GE/Zenon, for 2013, the discounted replacement price for all four (4) trains would be $1,240,000 versus
the market price of $1,940,000 (costs do not include installation, freight or taxes). Given the significant cost savings
associated with purchasing the membranes prior to the 10-year anniversary, we recommend that the Town budget
for the capital expense of replacement of half of the membranes and that a membrane inspection is made prior to
determining whether or not to make the purchase.
Supervisory Control and Data Acquisition (SCADA) System3.5.8
Through our evaluations we have identified several improvements to the Surfside WWTF SCADA system that would
enhance current operations. These recommended improvements are as follows:
Upgrade the IFIX software: the SCADA system depends on IFIX Software for its functionality. The version of
IFIX currently installed is outdated and does not work with newer versions of Microsoft Windows. If the one
of the existing computers were to fail and had to be replaced, it would come with a newer version of
Windows that would not be compatible with the IFIX software.
Provide remote access: installation of a hardware package that provides for secure remote access into the
SCADA system will allow WWTF operations staff to monitor and control the system as if they were sitting in
front of the SCADA PC at the Surfside WWTF which will save personnel time including prevention of
unnecessary trips to the facilities for off-hour nuisance alarms
Improve integration between the GE/Zenon system control panel and the SCADA master node: The
functionality of the GE/Zenon control panel should be fully accessible from the existing SCADA system. This
recommendation would accomplish the functionality.
Provide automatic report software: we recommend that reporting software (XLReporter) is included for the
SCADA system. This package can be configured to generate automatic reports of process variables and
alarms. Manual lab data can also be entered into the program to compare to readings received from online
instruments. The software can generate reports on any specified period (daily, weekly, monthly, etc.) and
can be formatted to be identical to regulatory agency reports to reduce the amount of staff time required for
reporting.
Provide operator training: development of a SCADA training plan for operations staff to take better
advantage of the SCADA system already in use at the wastewater sites within the Town.
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3.6 IMPROVEMENTS FOR ENERGY EFFICIENCY
As part of the CWMP, Woodard & Curran performed an energy efficiency evaluation of the Surfside WWTF to further
refine the recommendations of a National Grid Scoping Study Energy Evaluation. The evaluation was performed by
JK Muir LLC and is described in a memo dated July 2, 2014, which is provided in the appendices of the full report.
Refer to Appendix H for the full Report.
A summary of the recommended cost saving measures is a follows:
Provide instrumentation and controls modifications to allow automatic blower on/off cycling which will
minimize energy usage for the primary sludge holding tanks.
Provide instrumentation and controls modifications to allow automatic cycle blower on/off cycling which will
minimize energy usage for the secondary waste activated sludge holding tanks.
Modify the piping for the draft pumps that convey flow from the anoxic tanks to the aeration tanks to allow a
reduction in the number of pumps that need to run under reduced flow conditions.
Install a new VFD on the odor control fan and make programming changes to allow for a range of operating
conditions to optimize ventilation while minimizing energy usage.
There is a potential opportunity to modify the control system programming set points for the membrane air
scour blowers to optimize their usage and reduce the blower run time, which would reduce energy usage.
3.7 ESTIMATED CONCEPTUAL COST FOR IMPROVEMENTS
Woodard & Curran’s conceptual cost estimates for the Surfside WWTF improvements are summarized in the
following Table 3-1.
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Table 3-1: Surfside WWTF Recommended Improvements Cost Estimates
Construction
Design Engineering,
Permitting and Construction
Administration Subtotal
Contingency
(30%)Project Total
Improvements for Future Capacity
Blower Addition $388,000 $85,400 $473,000 $142,000 $615,000
Nitrified Recycle $371,000 $81,600 $453,000 $136,000 $589,000
Subtotal $1,204,000
Improvements for Reliability
Corrosion Control $361,000 $79,400 $440,000 $132,000 $572,000
Influent Screening and Vactor Truck Unloading $3,080,000 $677,000 $3,757,000 $1,127,000 $4,884,000
Aeration Tank Instrumentation $180,000 $40,000 $220,000 $66,000 $286,000
Primary Sludge Pump Replacement $176,000 $38,700 $215,000 $65,000 $280,000
Membrane Removal Equipment $116,000 $27,800 $144,000 $43,000 $187,000
Membrane Inspection and Replacement $806,000 $50,000 $856,000 $257,000 $1,113,000
SCADA Improvements $51,800 $60,800 $113,000 $34,000 $147,000
Subtotal $7,469,000
Improvements for Energy Efficiency
Sludge Blower Cycling $5,000 $5,000 $10,000 $3,000 $13,000
Secondary Sludge Blower Cycling $-$5,000 $5,000 $2,000 $7,000
Draft Pump Piping Modifications $7,500 $1,900 $9,000 $3,000 $12,000
Odor Control Fan VFD Implementation $25,500 $5,000 $31,000 $9,000 $40,000
MBR System Optimization $-$62,500 $63,000 $19,000 $82,000
Subtotal $154,000
Total $8,827,000
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The conceptual estimates are based on the following:
Equipment and materials costs were based on a combination of manufacturer budgetary quotations and
cost date we obtained from similar projects
Prevailing wage rates for labor
Project is tax exempt
Engineering and permitting services are included as allocations based on a percentage of the estimated
construction cost
A contingency of 30-percent is applied to the project cost
The conceptual cost estimates are indexed to the Engineering News Record (ENR) construction cost index
of 9681 for February 2014.
3.8 RE-EVALUATION OF LOADING AT SURFSIDE DISCHARGE BEDS
Background3.8.1
The major driver of this CWMP Update Report is the completion of Massachusetts Estuaries Program (MEP) Reports
at various embayment/estuary locations on Island that are documented as degraded due to nutrient loading with the
major contributor being on-site wastewater disposal systems. A thorough evaluation of the 2004 recommendation of
a satellite WWTF to service the Madaket and Warren’s Landing Needs Areas was completed, which included
extensive environmental review. As is detailed in the previous section, the Town requested that the need for a third
WWTF in Madaket be reviewed by evaluating the potential to service all of the area’s needs at its existing WWTF at
Surfside. The review was completed and based on the MEP results in multiple areas on Island, additional areas are
now being recommended for off-site wastewater treatment in order to reduce nitrogen loading to water resources.
The CWMP Update evaluated the potential to not only eliminate the design and construction of the Madaket WWTF,
but, also the potential to service the Needs Areas proposed in this geographic area at the existing Surfside WWTF.
Revised wastewater flows were calculated utilizing all updated land use information between 2004 and present and
included all Needs Areas recommended in this CWMP Update. A Capacity Analysis determined that Surfside WWTF
could handle the additional flows under its current permit with the limiting factor being the groundwater discharge
beds that are permitted to handle 3.5 MGD. A total of 4.0 MGD is needed to handle the total revised flows.
An initial meeting with MassDEP at their Boston offices on June 18, 2013 opened the discussion of increasing the
loading to the beds based on existing conditions and current operations. Subsequent to the June meeting, a Scope of
Work was developed and sent to MassDEP on August 16, 2013 and ultimately approved by MassDEP to complete a
hydrogeological evaluation to determine if loading the existing beds at a higher rate was feasible. This evaluation
agreed to look at three main items:
1) Capacity of existing beds to handle additional discharge through hydrogeological analysis;
2) Analysis of existing shoreline down gradient from WWTF relating to stability of shoreline; and
3) Determination of additional loading to identify any potential threat of breakout conditions to the down gradient
beach/shoreline area as a result of additional loading.
At the meeting on December 6, 2013, it was agreed that the model would be re-run utilizing both summer maximum
and average daily build out flows, with the summer max run for the month of August (4.0 MGD for August) and the
remainder of the year run at summer average daily flows at build out flows of 2.92 MGD. This schedule would also be
considered conservative as the Town stated the Surfside WWTF only receives the maximum summer flows for two
weeks in August.
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The following summarizes the current site conditions, the data utilized in the hydrogeological evaluation, including the
model and method for determining high groundwater, the actual analysis and results, the shoreline stability analysis,
potential for breakout determination and conclusions. This analysis will serve as the basis for the CWMP Update
recommendation for Surfside WWTF and for renewal of the Town’s Groundwater Discharge Permit No.SE#1-200,
which was extended by Chapter 238 of the Acts of 2012 and is now due on 6/15/2015.
MassDEP also required confirmation that the location of the beds on Nantucket’s southern shoreline was not
impacted with the revised FEMA maps. The new maps confirmed that the site was not subject to impacts, with recent
data maps from the United States Army Corps of Engineer after Hurricane Sandy. The Emergency Management
Director for Nantucket was contacted to discuss the site and any changes to the area that would be of concern. He
also contacted Coastal Zone Management (CZM) to assess their conclusions of this area and it was stated that there
were very few changes, if any; to this area and that the site was considered stable.
The Woodard & Curran approach to this Technical Memorandum, as described in our August 16th Scope of Work
was to replicate the modeling exercise that was completed in 2002 by EarthTech and reported on in their 2005
Groundwater Discharge Permit Application to support additional loading of existing beds without environmental or
public health impact.
Current Site Conditions3.8.2
The Surfside WWTF is located on the south side of Nantucket Island directly abutting the Atlantic Ocean. There are
presently 15 open sand beds currently in use for wastewater disposal after treatment at the Surfside MBR Facility.
Each of the beds contains approximately one acre in bottom area. On Sept 11, 2013, W&C’s geologist and Kevin
Manning (treatment plant operator from Nantucket) measured the bottom dimensions of each bed not described in
the As Built drawings developed by EarthTech, totaling 10 in all. The beds are of slightly different sizes, ranging from
the smallest at 35,700 square feet to the largest, which is about 44,900 square feet. The median size is 42400
square feet. The bed dimensions are shown in Table 3-2 below.
Table 3-2: Surfside Wastewater Discharge Bed Areas
North East Bed
South (ft) West (ft)Area (sqft)
1 *216 208 44928
2 *211 210 44310
3 *212 211 44732
4 *191 187 35717
5 *201 204 41004
6 *199 204 40596
7 *206 204 42024
8 *217 218 47306
9 *211 215 45365
10 x 200 193 38600
11 *198 201 39798
12 *189 204 38556
13 x 206 206 42436
14 x 212 212 44944
15 x 212 212 44944
TOTAL 635,260
* measured by Cary Parson and Kevin Manning 9-11-13
x taken from record drawings
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Using the above Table 3-2, with a 2,000,000 GPD Daily Flow and a total bed area of 635,260 that relates to a current
loading factor of 3.15 GPD/sqft.
The entire Surfside WWTF site is located in an area similar to Cape Cod and is composed of glacial outwash sands
and gravels. The aquifer is a simple water table aquifer with no complexities such as confining beds or semi-confined
layers. The full depth of the working aquifer is not known from borings Woodard& Curran has access to; however, the
EarthTech report utilized and noted in the next section suggests that the aquifer materials may extend to depths
greater than 200 feet. The EarthTech report details that the fresh water aquifer may only extend to 100 or 200 feet
based on the Ghyben-Herzberg principal. Ghyben-Herzberg states that for every 1 foot of fresh water that is standing
above sea level, the fresh water / salt water interface should be 40 feet below sea level.
The following map downloaded from Google Earth, Figure 3-1, shows an aerial view of the entire Surfside WWTF
site, including the WWTF, discharge beds and lower beach/shoreline area.
S SHORE RDBROO
K
S
A
V
E
Source: Esri, DigitalGlobe, GeoEye, i-cubed, USDA, USGS, AEX, Getmapping,Aerogrid, IGN, IGP, swisstopo, and the GIS User Community
MADAKET WASTEWATER TREATMENT PLANT
FIGURE 3-1
SCALE: 1" = 0.5 Miles
DATE: JAN. 2014 JOB NO.: 225139
DOC: WWTPMap.MXD
DRAWN BY: JSM SOURCE: MassGIS
.
COMPREHENSIVE WASTEWATERMANAGEMENT PLAN UPDATETOWN OF NANTUCKET, MA
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3.9 DATA UTILIZIED IN HYDROGEOLOGICAL EVALUATION
The greatest effort in this task was to establish the appropriate water table map for a typical August from data that is
available at this time. Fortunately, the earlier reports completed by EarthTech and GZA, provided the appropriate fall
high water table using the Frimpter method. Data obtained from various reports in the paper trail for the Surfside
location, (noted when used); have given Woodard & Curran some basic information to manipulate in trying to create
a typical August water table map. The process of creating the August water table map is described in a section
below.
Groundwater levels for the 2002 EarthTech report, drew on earlier work compiled in the 1980’s and 1990’s and used
the Frimpter Method to establish the necessary water table maps. The EarthTech report and the GZA report of 1980
both referenced a Sept 1979 GWL map presented in the GZA report of 1980. Woodard & Curran accepted the Sept
20, 1979 GWL map as representative of typical conditions in the August and Sept period of high flow for the
treatment plant and utilized this same data for this exercise.
Based on the description from EarthTech in their June 2005 report, Woodard & Curran built a nearly duplicate
groundwater model to the model presented in the EarthTech report. Woodard & Curran located the existing 15
disposal beds as they are now found in the field. Each disposal bed was given a different color in the model to signify
its disposal load. Refer to Figure 1 for the map downloaded from Google Earth as a site plan of the facility. The
Woodard & Curran model has three model layers as does the EarthTech model. These layers represent the
thickness of the fresh water aquifer and the aquifer thickness increases as one moves from the shore line back into
the interior of the island.
The GW model chosen for this modeling exercise is the same as used by EarthTech. This is the MODFLOW model
from the USGS, perhaps the most widely used model in groundwater level prediction. The Woodard & Curran model
was constructed to mimic the EarthTech model as closely as possible. The model was calibrated against the only
recently published groundwater table map for the area, the Sept 20, 1979 map published by GZA in their 1980 report
and reused by EarthTech in the GDP application of 2005.
Exact model data files were not published by EarthTech in their 2005 report, however, from the data given, Woodard
& Curran has closely reproduced the model. The calibration statistics for the Woodard & Curran model are given in
the Table 3-3.
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Table 3-3: Woodard & Curran Calibration Statistics
Name Observed Computed Residual
N-1 2.7 2.9 -0.19149
N-8 2 2.9 -0.88175
SU-M 3.7 3.3 0.354274
N-13 3.8 3.7 0.108642
N-5 4.3 4.2 0.130373
N-3 4.1 4.1 0.044081
N-4 4.5 3.8 0.685391
N-6 4.3 4.5 -0.22127
N-9 4.6 5.2 -0.59368
Residual Mean -0.06283
Absolute Residual Mean 0.356774
Residual Std. Deviation 0.447967
Sum of Squares 1.841593
RMS Error 0.452351
Min. Residual -0.88175
Max. Residual 0.685391
Number of Observations 9
Range in Observations 2.6
Scaled Residual Std. Deviation 0.172295
Scaled Absolute Residual Mean 0.137221
Scaled RMS Error 0.173981
Scaled Residual Mean -0.02416
The calibration statistical values presented in Table 3-3 above are representative to those presented in the
EarthTech Report and suggests a reasonably solid calibration for the W&C model.
Calculations of Typical Fall Water Table3.9.1
As mentioned above, the earlier reports from GZA and EarthTech have reported that due to conditions of the beds
being in continual service, the Frimpter Method is the only method for determining reasonable groundwater levels at
the site.(see page 5-EarthTech GWD permit application-6-28-05). Woodard & Curran has not attempted to rerun the
Frimpter method for estimating groundwater levels in the fall. We have accepted the water levels as presented via
the Frimpter method in the EarthTech report for Sept 20, 1979.
Below, we present our discussion for working with the Frimpter groundwater levels.
Water Table3.9.2
Woodard & Curran prepared a water-table contour map for Surfside using September 1979 data, the period for which
a pre-existing groundwater-flow model was constructed (EarthTech, 2002). Groundwater-elevation data are from
gauging events conducted by GZA personnel (GZA, 1980) prior to construction of the Surfside treatment facility. The
contours presented in Figure 3-2 from the Earth Tech Report, below, indicate a southerly flow of groundwater toward
the coastline. It should be noted that GZA adjusted the manually gauged water levels via the Frimpter Method to
obtain an annually average data set, which was used for calibration of the flow model. The original data represented
a seasonally dry period, and were increased by approximately 0.2 feet. Woodard & Curran incorporated the historic
1979 data, with the 2002 Frimpter adjustment, to generate potentiometric contours and flow directions, and to
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calibrate a steady state flow model. The model then is used to simulate groundwater mounding at Surfside in
response to increases in discharge of treated effluent.
Current data are available at Surfside, which include five groundwater wells, which are gauged by Surfside personnel
on a quarterly basis. However, the newly installed wells do not have surveyed measuring points, and topographic
maps exhibit a discrepancy of elevation compared with historical well surveys. In addition, the methodology for recent
gauging events includes measuring the height of water column from the bottom of the well. Over time, wells may
accumulate silt from the surrounding formation, or may be clogged with foreign material deposited in the well. Thus,
the height of water column may change over time irrespective of a constant depth to groundwater. Furthermore, the
recent data represents a system currently subjected to discharged effluent, whereas the historical data set is more
representative of a steady state, long-term, ambient environment. For these reasons, the historical data set is used
for constructing a base model upon which to observe the response to discharged of treated effluent. As was
discussed at the December 6th meeting, the Town will have the wells surveyed for future readings.
In an additional effort to compare the Woodard& Curran model to the EarthTech model, we duplicated the EarthTech
example of loading the beds with 3.4 MGD to try for similar groundwater contours. The match of groundwater levels
was very close, confirming that the Woodard & Curran model is a close replica of the models previously approved.
One can reference the following Figure 3-2 as an example of the groundwater level that was used as the calibrated
groundwater map to which the proposed increased effluent flow to a maximum load of 4 MGD in the August
timeframe was applied. The groundwater levels shown on Figure 3 are very similar to the levels shown on Figure 2 in
the 2005 EarthTech GDA submittal.
With the Woodard & Curran Groundwater model properly calibrated, we moved on with the effort to simulate the
aquifer response to applying the treated effluent as discussed at the December 6th meeting; summer flow at full build
out at 4.0 MGD for the entire month of August only and the remainder of the year at the summer average daily flow at
full buildout of 2.92 MGD to the beds at Surfside. The results of this transient modeling effort are shown on Figures 4
through 15, with Figure 11 - August, showing the most dramatic mound. The simulation shows 4.0 MGD for the entire
month of August, which is conservative given the Town receives maximum flows for a two week period in August.
These figures can be found in BRP-83 included in Appendix H.
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The groundwater elevation under the beds in the no-load static condition, Figure 3-3, is 2.73 feet mean sea level
(msl) with the month of August loading rate at 9.26 feet msl, which shows a 6.53 foot groundwater mound. Referring
to the Earth Tech record drawing in Attachment A of the full report, this shows the bottom of bed #12 at elevation 13
feet. In Figure 13, the modeling shows contours on bed #12 (highest groundwater elevation is in bed #12) at
approximately 9 feet at end of month. This shows an approximate vertical separation of 4 feet as the worst case
scenario in all models. All other loading scenarios exceed the four foot separation with the mound considerably less
than in August.
3.10 SUMMARY OF HYDROGEOLOGICAL ANALYSIS
The aquifer response to application of 3.4 MGD as modeled by EarthTech was to mound to levels of 8 feet (+) in the
center of the discharge beds. When the discharge was increased to the transient model in the Woodard & Curran
models, as expected the August scenario showed the most dramatic mound. All other scenarios showed
considerably less mounds with vertical separations exceeding four feet in all beds.
The new models also show that all flow is directed towards the ocean. With the maximum load period of August at full
build out flow of 4.0 MGD, Figure 19 details a Particle Trace that shows all flows going to the ocean. There is no
impact of flow shown towards Miacomet Pond.
The revised transient models clearly show that a vertical separation of four feet is maintained at all beds during the
year with the new proposed flow of 4.0MGD. Refer to Figure 3-3 for a No Load Flow; Figure 3-4 for Typical Summer
Flow; and Figure 3-5 Typical Winter flow. Each of the twelve months were modeled and are included in the full report
in Appendix H.
Figure 3
STATIC GROUNDWATER
CONTOURS
(NO LOADING)
Figure 11
AUGAT
4.0MGD
Figure 5
FEBAT
2.92MGD
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Based on the above-referenced permit filings, it has been determined that the Surfside WWTF discharge beds are
approved to support 4.0 MGD and the existing Groundwater Discharge Permit will be modified to reflect this. At the
time of this Report writing, MassDEP was in the process of revising the Groundwater Discharge Permit to reflect the
revised flow of 4.0 MGD. Refer to Appendix H for copies of the filings and responses.
3.11 SHORELINE STABILITY ANALYSIS AND BREAKOUT DETERMINATION
The second task to address is the potential impact that additional flow at the Surfside Beds could have to the
shoreline immediately down gradient by some 250 to 300 feet. We evaluated impacts of both shoreline stability and
any potential for additional flow to breakout in the down gradient areas. To address this concern, Woodard & Curran
resorted to existing published document from the Woods Hole Group, as well as recent datasets produced by the
United States Army Corps of Engineers (ACOE). These documents address the stability of the shore line near the
Surfside Beds with a review of several existing studies of the shoreline position in the area.
Shoreline3.11.1
A review of the shoreline analysis by the Woods Hole Group (WHG, 2002) suggests that the shoreline near the
Surfside WWTF has experienced consistent patterns of accretion or erosion from 1955 to 2002. Shoreline change
during older datasets in the 1800s show greater fluctuation, which is not mimicked in recent data, either due to
unique climatic factors or to greater discrepancies in data translation. Data from the WHG report indicate overall
slight erosional trends in the shoreline immediately west of Surfside, stable trends south of Surfside, and accretion
southeast and east of Surfside. WHG determined the average accretion or erosion rate for the period from 1955 to
2002 along transects running perpendicular to the shoreline. In general, the erosion rates southwest and west of
Surfside range from zero to 0.4 ft/year, the rates immediately south of Surfside show little variance around zero, and
the rate of change southeast and east of Surfside range from less than 1 ft/yr to 5 ft/yr.
An investigation by Woodard & Curran, using data from the Massachusetts Ocean Resource Information System
(MORIS) database, yielded similar trends as shown on Figure 16 below. Erosion and accretion rates from 1955 to
2009 were calculated along MORIS shoreline transects in the vicinity of Surfside. In general, the western half of
Surfside experienced weak erosion during the study period (less than 1 ft/yr), and the shoreline in the eastern half of
Surfside experienced strong accretion (0.7 to 3.6 ft/yr).
Figure 16 represents the general shore line progression near the Surfside Beds from 1955 until 2009. In general, the
shore line appears to be accreting along the area of the Beds. The shore line in place now includes the passage of
Hurricane Sandy. Thus it seems that the natural shoreline processes are not eroding the area around the Surfside
Beds.
A second part of the question about shoreline stability dealt with the likelihood that the additional groundwater
movement of groundwater from the Surfside Beds toward the ocean will make the dune banking in the area more
susceptible to erosion under natural processes. To address this question Woodard& Curran compared the
groundwater gradient in the area under the proposed increased discharge of wastewater to the typical required
gradient in wastewater plumbing for domestic use. Domestic plumbing codes typically require a 1 inch drop in 8 feet
of piping to move solids along an open pipe. This is a gradient of 0.125 inches per foot. The groundwater gradient
after the proposed additional disposal at Surfside will be 0.016667 inches /inch, about 1/10 the gradient in domestic
wastewater piping. Based on this comparison, the new groundwater gradient will not be steep enough to destabilize
the slope at the ocean.
Additional datasets produced by the ACOE after Hurricane Sandy also support the shoreline stability in the Surfside
WWTF area. Refer to Figure 3-6.
Town of Nantucket (#225139.00)3-23 Woodard & Curran
Final CWMP Update Report Volume I October 2014
Additionally, the revised FEMA maps were reviewed to determine any changes as a result of the mapping updates
and what, if any, issues this presents at this site. As discussed in previous sections of this TM, the Town’s
Emergency Management Director who is in charge of the flood zones stated that there were no changes to the site
and that there are no potential impacts to the Surfside Site. CZM also conferred with him and referred to the site as
stable. Refer to Figure 18 for a copy of the FEMA map.
Results of the WHG, ACOE, FEMA and Woodard & Curran investigations suggest that the shoreline of Surfside is
experiencing overall accretion from the mid-20th century to present. Weak erosion along the western region of the
study area may continue, with an associated accretion of shoreline to the east with no impact to the WWTF.
3.12 CONCLUSIONS OF EVALUATION
The conclusions of the above tasks are as follows:
Additional Bed Loading3.12.1
Additional loading to the existing beds at the Surfside WWTF, from 3.4 MGD to 4.0 MGD, based on summer loading
at 4.0 MGD for the entire month of August only and at 2.92 MGD (summer average daily flow) for the remainder of
the year is feasible under current conditions. The transient models detail the most dramatic mound during the month
of August, which is expected given the maximum loading rate of 4.0 MGD for the entire month. While the modeling
shows that additional loading raises the mounds in the upper beds, the overall system is able to handle the additional
flow with vertical separation in the four foot range in bed #12, which previous records detail with the highest
groundwater elevation. The remainder of the year under the transient models clearly shows considerably less
mounding with vertical separations exceeding four feet. Additionally, the upgrades at the WWTF, most notably the
upgrade to MBR technology, afford a highly treated effluent discharge that travels to the open Atlantic Ocean with no
environmental impacts.
The full flow to 4.0 MGD will not be seen immediately, but, rather over a 20-year planning period. It is also in the
Town’s CWMP Update as an alternative, to maintain communication with MassDEP and various Cape and
southeastern Massachusetts towns in the use of an ocean outfall. In a best case scenario at some point in the future,
the treated effluent from Surfside could be discharged through an outfall to the Atlantic Ocean.
Shoreline Stability3.12.2
This evaluation determined that the shoreline is stable and not subject to severe, impacts of erosion.
Breakout Potential3.12.3
The evaluation determined that no breakout will occur as a result of additional loading to the existing beds.
Particle Trace Analysis3.12.4
The model was run utilizing the August load period of 4.0 MGD in order to determine the direction of the flow. Figure
3-7 clearly details all flow towards the ocean. No flow is directed towards Miacomet Pond.
The most recent FEMA maps of the Surfside shoreline are included in Figure 3-
Town of Nantucket (#225139.00)3-27 Woodard & Curran
Final CWMP Update Report Volume I October 2014
3.13 UPDATED RECOMMENDED PLAN
CWMP Update Final Recommended Plan3.13.1
A variety of wastewater alternatives were investigated in the 2004 Phase I CWMP and both the Phase II and Phase
III Reports to determine the appropriate wastewater facilities to meet the needs of Nantucket at that time. At that time
the alternatives evaluation completed was compiled on the then recommended Needs Areas, environmental
screening ratings, and preliminary engineering and technical criteria. This CWMP Update has relooked at the 2004
evaluations and as was detailed in previous sections, updated this information based on current conditions on Island.
This update included various records reviews, as well as meetings with the local jurisdictions, including the Board of
Health and all Massachusetts Estuaries Project Reports, as to how the actual physical characteristics of each
geographical area supported either an on-site or off-site wastewater solution and to what environmental impacts are
present. Alternatives re-evaluated included optimizing on-site wastewater disposal systems, Innovative/Alternative
Systems, satellite wastewater systems and optimizing the existing wastewater facilities on Island-the Surfside
WWTF. All of the above-referenced alternatives are included in Nantucket’s long-term planning as detailed in
Chapter 2 in “Updated Needs Areas and Revised Wastewater flows and Loads” starting on page 2-57.
The following section highlights the plan for each Needs Area recommended for municipal sewer, as well as
associated environmental impacts. Figure 3-9 details the overall proposed collection system layout and downstream
route to the Surfside WWTF. Additionally, those areas recommended to remain on-site with I/A systems and septage
management are detailed. Figures 3-10 through 3-13 detail the environmental constraints present along the
proposed infrastructure. It is noted that the entire Island is overlain by NHESP as shown on Figure 3-X. Care has
been taken to identify specific resources, such as vernal pools, and identified any potential impacts. Capital costs
follow the Needs Areas recommendations in this section.
Needs Areas in Surfside Wastewater Collection System3.13.2
3.13.2.1 Madaket
The Madaket Study Area was evaluated in the 2004 Phase I Report as long-term unsustainable with the current on-
site wastewater disposal systems or simply a “Needs Area” and maintains this determination in this CWMP Update.
Out of the four options evaluated in the Phase III Report as a solution for this Needs Area, the most feasible is
installation of Low-Pressure Sewers. Additionally, the MEP Report completed for this geographical area also
determined that in order to meet the established TMDL for Madaket Harbor/Long Pond, wastewater needs to be
removed from the Watershed.
The Final Recommended Plan for the Madaket Needs Area consists of the construction of approximately 40,700
linear feet of low-pressure sewer with sizes ranging from 1-1/4 to 4 inch diameter pipe. All low-pressure sewers will
be located in existing, pre-disturbed roadways. The sewers will connect to the proposed new pump station to be
located at the municipally-owned DPW parcel on Madaket Road, which will then pump the wastewater from both the
Madaket Needs and the Warren’s Landing Needs Areas via an approximately 16,800 linear foot force main that
discharges to new sewer within the Hummock North and Somerset Needs Areas. Sewer within the Somerset Needs
Area will connect to the existing collection system around the intersection of Bartlett Road and Mizzenmast Road,
and then be pumped to the Surfside WWTF by the Pine Valley and Surfside Road Pump Stations. Figure 3-14 shows
the proposed Madaket/warrens Landing Collection System. All sewers are presently proposed to be located in the
pre-disturbed right of ways and/or roadways and are proposed to be constructed with no trenches utilizing directional
drilling. This method of construction will avoid any open trenches, roadway disturbances on many small and one-
vehicle travel lanes and eliminates any potential impact to multiple resources.
Based on Woodard & Curran’s preliminary evaluation of the downstream sewer infrastructure using the Town’s GIS
mapping, approximately 1,500 linear feet of sewer on Mizzenmast Road and approximately, 3,500 linear feet on
Town of Nantucket (#225139.00)3-28 Woodard & Curran
Final CWMP Update Report Volume I October 2014
Bartlett Road and Surfside Road will need to be upgraded to allow adequate capacity for wastewater flows from
Madaket, Warren’s Landing and Somerset. Upgrades for the Pine Valley and Surfside Road Pump Stations will also
likely be necessary. The capacity analysis completed during Final Design will determine the extent of and timing of
upgrades.
3.13.2.1.1 Environmental Impact
This Needs Area is overlain with NHESP, has wetlands dispersed throughout and includes coastal areas impacted by
FEMA Flood Zones. There are vernal pools noted along the Madaket Road route from this Needs Area to the
proposed pump station located at the DPW site, but there is no impact to these resources as the infrastructure is
across the street from the resources. With the proposed layout of infrastructure and based on the above-referenced
information, no environmental impact with the planning level concept is foreseen. There is no infrastructure proposed
within the Flood or velocity zones. All proposed infrastructure is detailed as in existing, pre-disturbed right of ways
and/or roadways. The use of directional drilling with the low-pressure sewers eliminates many potential threats to
environmental resources. During the Final Design Phase of the Project, should any questions arise as to impacts to
environmental resources within the Project limits, the appropriate agency will be contacted and all issues will be
addressed accordingly.
3.13.2.2 Warren’s Landing
The Warren’s Landing Need Area was evaluated in the 2004 Phase I Report as long-term unsustainable with the
current on-site wastewater disposal systems or simply a “Needs Area” and maintains this determination in this
CWMP Update. Out of the four options evaluated in the 2004 Phase III Report as a solution for this Needs Area, the
most feasible continues to be the use of Low-Pressure Sewers. Additionally, the MEP Report completed for this
geographical area also determined that in order to meet the established TMDL for Madaket Harbor/Long Pond,
wastewater needs to be removed from the Watershed.
The Final Recommended Plan for the Warren’s Landing Needs Area consists of installation of approximately 6,300
linear feet of low-pressure sewer with sizes ranging from 1-1/4 to 4 inch diameter pipe. All low-pressure sewers will
be located in pre-disturbed, existing right of ways and roadways. The sewers will connect to the proposed pump
station to be located on Town-owned land at the DPW on Madaket Road, which will then pump the wastewater from
both Warren’s Landing and Madaket Needs Areas via an approximately 16,800 linear foot forcemain that discharges
to new sewer within the Hummock North and Somerset Needs Areas. Sewer within the Somerset Needs Area will
connect to the existing collection system around the intersection of Bartlett Road and Mizzenmast Road, and then be
pumped to the Surfside WWTF by the Pine Valley and Surfside Road Pump Stations. Figure 3-14 includes the
proposed Warren’s Landing Collection System layout.
Based on Woodard & Curran’s preliminary evaluation of the downstream sewer infrastructure using the Town’s GIS
mapping, approximately 1,500 linear feet of sewer on Mizzenmast Road and approximately, 3,500 linear feet on
Bartlett Road and Surfside Road will need to be upgraded to allow adequate capacity for Madaket, Warren’s Landing
and Somerset flows. Upgrades for the Pine Valley and Surfside Road Pump Stations will also likely be necessary.
The capacity analysis completed during Final Design will determine the extent of and timing of upgrades.
3.13.2.2.1 Environmental Impact
This Needs Area is overlain with Natural Heritage and Endangered Species Program delineation. (NHESP). There
are vernal pools noted along the Madaket Road route from this Needs Area to the proposed pump station located at
the DPW site, but there is no impact to these resources as the infrastructure is across the street from the resources.
With the proposed layout of infrastructure and based on the above-referenced information, no environmental impact
with the planning level concept is foreseen. All proposed infrastructure is detailed as in existing, pre-disturbed right of
ways and/or roadways. The use of directional drilling with the low-pressure sewers eliminates many potential threats
Town of Nantucket (#225139.00)3-29 Woodard & Curran
Final CWMP Update Report Volume I October 2014
to environmental resources. During the Final Design Phase of the Project, should any questions arise as to impacts
to environmental resources within the Project limits, the appropriate agency will be contacted and all issues will be
addressed accordingly.
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DATE: FEB. 2014 JOB NO.: 225139
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DATE: NOV. 2013 JOB NO.: 225139
DOC: ConceptLayout.MXD
DRAWN BY: JSM SOURCE: MassGIS & Town
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Town of Nantucket (#225139.00)3-36 Woodard & Curran
Final CWMP Update Report Volume I October 2014
3.13.2.3 Somerset
The Somerset Study Area was evaluated in the 2004 Phase I Report as long-term unsustainable with the current on-
site wastewater disposal systems or simply a “Needs Area” and maintains this determination in this CWMP Update.
Out of the four options evaluated in the 2004 Phase III Report as a solution for this Needs Area, the most feasible is
a combination of Conventional Gravity Sewers and Low-Pressure Sewers.
The Recommended Plan consists of the installation of approximately 20,500 linear feet of sewer composed of both
gravity pipe and low-pressure sewer. The extent of each sewer type will be determined during final design. The need
for any new pump stations will also be determined during preliminary design and any pump stations identified will be
submersible and installed in the existing right of way. Figure 3- 15 shows the proposed Somerset Collection System
layout.
Somerset’s collection system will join the Town’s existing gravity sewer on Bartlett Road and be pumped to the
Surfside Road Pump Station via Pine Valley Pump Station. The Surfside Road Pump Station will pump the
wastewater flow to the Surfside Wastewater Treatment Facility for treatment and disposal. Based on Woodard &
Curran’s preliminary evaluation of the downstream sewer infrastructure using the Town’s GIS mapping,
approximately 1,500 linear feet of sewer on Mizzenmast Road and approximately, 3,500 linear feet on Bartlett Road
and Surfside Road will need to be upgraded to allow adequate capacity for Madaket, Warren’s Landing and
Somerset flows. Upgrades for the Pine Valley and Surfside Road Pump Stations will also likely be necessary. The
capacity analysis completed during Final Design will determine the extent of and timing of upgrades.
3.13.2.3.1 Environmental Impact
This Needs Area is overlain by NHESP. Based on the above-referenced information, no environmental impact with
the planning level concept is foreseen. All proposed infrastructure is detailed as in existing, pre-disturbed right of
ways and/or roadways. In areas proposed and conducive to directional drilling, the use of directional drilling
eliminates many potential threats to environmental resources. Conventional Gravity Sewers will be designed within
existing right of ways and/or roadways to eliminate any threat to environmental resources. During the Final Design
Phase of the Project, should any questions arise as to impacts to environmental resources within the Project limits,
the appropriate agency will be contacted and all issues will be addressed accordingly.
3.13.2.4 Hummock North
The Hummock North Area was evaluated in this CWMP Update and identified as long-term unsustainable with the
current on-site wastewater disposal systems or simply a “Needs Area” as further described in Section 2. Additionally,
the MEP Report completed for this geographical area also determined that in order to meet the established water
quality thresholds for Hummock Pond, it is recommended that wastewater be removed from the Watershed.
Out of the options evaluated in the CWMP Update as a solution for this Needs Area, the most feasible is a
combination of Conventional Gravity Sewers and/or Low-Pressure Sewers.
The Recommended Plan consists of the installation of approximately 45,800 linear feet of sewer composed of both
gravity pipe and/or low-pressure sewer. The extent of each sewer type will be determined during the Final Design
Phase of the Project. All sewers are proposed to be located in the pre-disturbed right of ways and or roadways. The
need for any new pump stations will also be determined during Final Design and any pump stations identified will be
submersible and installed in existing right of ways. Figure 3-16 shows the proposed Hummock Pond North Collection
System layout.
Town of Nantucket (#225139.00)3-37 Woodard & Curran
Final CWMP Update Report Volume I October 2014
The Hummock North collection system will join the Town’s existing gravity sewer system through the Somerset
Needs Area. Based on Woodard & Curran’s preliminary evaluation of the downstream sewer infrastructure using the
Town’s GIS mapping, approximately 1,500 linear feet of sewer on Mizzenmast Road and approximately, 3,500 linear
feet on Bartlett Road and Surfside Road will need to be upgraded to allow adequate capacity for Hummock North and
Somerset flows. Upgrades for the Pine Valley and Surfside Road Pump Stations will also likely be necessary. The
capacity analysis completed during Final Design will determine the extent of and timing of upgrades.
3.13.2.4.1 Environmental Impact
This Needs Area is overlain by NHESP and includes a vernal pool location. There are wetlands dispersed throughout
the geographic area. Based on the above-referenced information, no environmental impact with the planning level
concept is foreseen. The Town will work with the local Conservation Commission during design and address these
areas accordingly. All proposed infrastructure is detailed as in existing, pre-disturbed right of ways and/or roadways.
In areas proposed and conducive to directional drilling, the use of directional drilling eliminates many potential threats
to environmental resources. Conventional Gravity Sewers will be designed within existing right of ways and/or
roadways to eliminate any threat to environmental resources. During the Final Design Phase of the Project, should
any questions arise as to impacts to environmental resources within the Project limits, the appropriate agency will be
contacted and all issues will be addressed accordingly.
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FIGURE 3-15
SCALE:
DATE: NOV. 2013 JOB NO.: 225139
DOC: ConceptLayout.MXD
DRAWN BY: JSM SOURCE: MassGIS & Town
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Legend
Wastewater Pipes
D FORCE MAIN
D LOW PRESSURE
DD OVERFLOW PIPE
D GRAVITY MAIN, 4"
D GRAVITY MAIN, 6"
D GRAVITY MAIN, 8"
D GRAVITY MAIN, 10"
D GRAVITY MAIN, 12"
D GRAVITY MAIN, 15"
D GRAVITY MAIN, 18"
D GRAVITY MAIN, 20"
D GRAVITY MAIN, 24"
D GRAVITY MAIN, 30"
D GRAVITY MAIN, Unknown Diam.
Proposed Sewer
Impervious Cover
Pond
Wetland
Town Sewer District
COMPREHENSIVE WASTEWATERMANAGEMENT PLAN UPDATETOWN OF NANTUCKET, MA
HUMMOCK NORTH NEEDS AREACONCEPTUAL LAYOUT
FIGURE 3-16
SCALE:
DATE: NOV. 2013 JOB NO.: 225139
DOC: ConceptLayout.MXD
DRAWN BY: JSM SOURCE: MassGIS & Town
1 inch = 1,000 feet
Town of Nantucket (#225139.00)3-40 Woodard & Curran
Final CWMP Update Report Volume I October 2014
3.13.2.5 Hummock South
The Hummock South Area was evaluated in this CWMP Update and identified as long-term unsustainable with the
current on-site wastewater disposal systems or simply a “Needs Area” as further described in Section 2.
Out of the options evaluated in the CWMP Update as a solution for this Needs Area, the most feasible is a
combination of Conventional Gravity Sewers and/or Low Pressure Sewers.
The Recommended Plan consists of the installation of approximately 32,800 linear feet of sewer composed of both
gravity pipe and low-pressure sewer. The extent of each sewer type will be determined during Final Design. All
sewers are proposed to be located in the pre-disturbed existing right of ways and/or roadways. The need for pump
stations will also be determined during Preliminary Design and any pump stations will be submersible and installed in
existing right of ways. Figure 3-17 shows the proposed Hummock Pond South Collection System layout.
The Hummock South collection system will join the Hummock North collection system and the Somerset System and
then join the Town’s existing collection system on Bartlett Road and be pumped to the to the Surfside Road Pump
Station via Pine Valley Pump Station,. The Surfside Road Pump Station will pump the wastewater flow to the
Surfside Wastewater Treatment Facility for treatment and disposal. Based on Woodard & Curran’s preliminary
evaluation of the downstream sewer infrastructure using the Town’s GIS mapping, approximately 1,500 linear feet of
sewer on Mizzenmast Road and approximately, 3,500 linear feet on Bartlett Road and Surfside Road will need to be
upgraded to allow adequate capacity for Hummock South, Hummock North, and Somerset flows. Upgrades for the
Pine Valley and Surfside Road Pump Stations will also likely be necessary. The capacity analysis completed during
Final Design will determine the extent of and timing of upgrades.
3.13.2.5.1 Environmental Impact
This Needs Area is overlain by NHESP. There are wetlands dispersed throughout the geographic area. The Town
will work with the local Conservation Commission during design and address these areas accordingly. The south
coastal area is included within FEMA Flood Zones, but no infrastructure is proposed within this or the velocity zone.
This will be further addressed during design phase. Based on the above-referenced information, no environmental
impact with the planning level concept is foreseen. All proposed infrastructure is detailed as in existing, pre-disturbed
right of ways and/or roadways. In areas proposed and conducive to directional drilling, the use of directional drilling
eliminates many potential threats to environmental resources. Conventional Gravity Sewers will be designed within
existing right of ways and/or roadways to eliminate any threat to environmental resources. During the Final Design
Phase of the Project, should any questions arise as to impacts to environmental resources within the Project limits,
the appropriate agency will be contacted and all issues will be addressed accordingly.
3.13.2.6 Miacomet
The Miacomet Area was evaluated in this CWMP Update and identified as long-term unsustainable with the current
on-site wastewater disposal systems or simply a “Needs Area” as further described in Section 2. While there is no
formal MEP Study active for this watershed, the Town is evaluating the current watershed delineations and potential
threats to the freshwater Pond’s water quality. Years of annual water quality testing results show significant
degradation to the Pond, which supports removal of on-site wastewater in this geographic area. This is further
detailed throughout this Report.
Out of the options evaluated in the CWMP Update as a solution for this Needs Area, the most feasible is a
combination of Conventional Gravity Sewers and Low-Pressure Sewers. The Recommended Plan consists of the
installation of approximately 27,100 linear feet of sewer composed of both gravity pipe and/or low-pressure sewer.
The extent of each sewer type will be determined during Final Design. All sewers are proposed to be located in the
pre-disturbed existing right of ways and/or roadways. The need for construction of pump stations will also be
Town of Nantucket (#225139.00)3-41 Woodard & Curran
Final CWMP Update Report Volume I October 2014
determined during Preliminary Design, however, any pump stations will be submersible and installed in the existing
right of ways. The Miacomet collection system may potentially be able to connect to the Sherburne Commons
infrastructure and/or the Abrem’s Quarry Pump Stations, and potentially to the Surfside Pump Station. This will be
determined during Final Design. Figure 3-18 shows the proposed Miacomet Collection System layout.
Based on Woodard & Curran’s preliminary evaluation of the downstream sewer infrastructure using the Town’s GIS
mapping, approximately 2,100 feet of sewer on Miacomet Road and Surfside Road may need to be upgraded to
allow adequate capacity for Miacomet flows to connect to the Surfside Pump Station, depending on the layout of the
sewer determined during final design. Upgrades for the Surfside Road Pump Station will also likely be necessary.
The capacity analysis completed during Final Design will determine the extent of and timing of upgrades.
3.13.2.6.1 Environmental Impact
This Needs Area is overlain by NHESP. Based on the above-referenced information, no environmental impact with
the planning level concept is foreseen. There is a significant portion of this geographic area currently serviced by
municipal sewer with infrastructure that currently is active and can be utilized to connect additional areas proposed in
this Needs Area. All proposed new infrastructure is detailed as in existing, pre-disturbed right of ways and/or
roadways. In areas proposed and conducive to directional drilling, the use of directional drilling eliminates many
potential threats to environmental resources. Conventional Gravity Sewers will be designed within existing right of
ways and/or roadways to eliminate any threat to environmental resources. During the Final Design Phase of the
Project, should any questions arise as to impacts to environmental resources within the Project limits, the appropriate
agency will be contacted and all issues will be addressed accordingly.
3.13.2.7 Monomoy
The Monomoy Area is determined to be a Needs Area based on the Area’s proximity to and potential impact relative
to the Massachusetts Estuaries Program to the Nantucket Harbor Watershed and maintains this recommendation in
this CWMP Update. Currently, a portion of the developed lots are within the Town Sewer District and are already
connected to the Town Sewer District collection system that conveys wastewater to the Surfside Wastewater
Treatment Facility. The Recommended Plan consists of connecting the remaining parcels in the delineated Needs
Area via installation of approximately 30,800 linear feet of sewer. The type of sewer will be determined during Final
Design, but will likely include a combination of gravity sewer and low-pressure sewer. A portion of the collection
system in Monomoy will connect to the Monomoy South Pump Station and another portion of the collection system
will travel down Polpis Road to Milestone Road connecting the Monomoy and Shimmo Collection Systems to the
Town Collection System. Note that this option eliminates this area from having to travel to the Sea Street Pump
Station.
Based on Woodard & Curran’s preliminary evaluation of the downstream sewer infrastructure using the Town’s GIS
mapping, this whole system would connect to the Surfside Road Pump Station, which will pump the wastewater flow
to the Surfside Wastewater Treatment Facility for treatment and disposal. All sewers are proposed to be located in
pre-disturbed existing right of ways and/or roadways. Refer to Figure 3-19 for the proposed layout of the Monomoy
Collection System.
3.13.2.7.1 Environmental Impact
This Needs Area is overlain by NHESP. There are areas that are within the Zone II of the public water supply and
coastal areas abut the FEMA Flood Zone. Based on the above-referenced information, no environmental impact with
the planning level concept is foreseen. All proposed new infrastructure is detailed as in existing, pre-disturbed right of
ways and/or roadways. There is a significant portion of this geographic area currently included within the approved
Town Sewer District serviced by municipal sewer with infrastructure that currently is active and can be utilized to
connect additional areas proposed in this Needs Area. The removal of on-site wastewater systems in this geographic
Town of Nantucket (#225139.00)3-42 Woodard & Curran
Final CWMP Update Report Volume I October 2014
area removes any potential threats to the public water supply. In areas proposed and conducive to directional drilling,
the use of directional drilling eliminates many potential threats to environmental resources. Conventional Gravity
Sewers will be designed within existing right of ways and/or roadways to eliminate any threat to environmental
resources. During the Final Design Phase of the Project, should any questions arise as to impacts to environmental
resources within the Project limits, the appropriate agency will be contacted and all issues will be addressed
accordingly.
3.13.2.8 Shimmo
The Shimmo Area was evaluated in the 2004 Phase I Report and determined to be a Needs Area based on the
Area’s proximity to and potential impact relative to the Massachusetts Estuaries Program to the Nantucket Harbor
Watershed and maintains this recommendation in this CWMP Update. Out of the options evaluated in the CWMP
Update as a solution for this Needs Area, the most feasible is a combination of Conventional Gravity Sewers and
Low-Pressure Sewers. The Recommended Plan consists of the installation of approximately 32,600 linear feet of
low-pressure sewer with sizes ranging from 1-1/4 to 4 inch diameter pipe. All sewers are proposed to be located in
pre-disturbed existing right of ways and/or the roadways. The Shimmo collection system will tie in directly to the
gravity sewer in the Monomoy Needs Area via Polpis Road. Figure 3-20 provides a layout for the proposed Shimmo
Collection System.
Based on Woodard & Curran’s preliminary evaluation of the downstream sewer infrastructure using the Town’s GIS
mapping, this whole collection system would connect to the Surfside Road Pump Station, which will pump the
wastewater flow to the Surfside Wastewater Treatment Facility for treatment and disposal.
3.13.2.8.1 Environmental Impact
This Needs Area is overlain by NHESP. The immediate area abutting Nantucket Harbor lies within the FEMA Flood
Zone, but no infrastructure is planned within this area. Based on the above-referenced information, no environmental
impact with the planning level concept is foreseen. All proposed new infrastructure is detailed as in existing, pre-
disturbed right of ways and/or roadways. In areas proposed and conducive to directional drilling, the use of
directional drilling eliminates many potential threats to environmental resources. Conventional Gravity Sewers will be
designed within existing right of ways and/or roadways to eliminate any threat to environmental resources. During the
Final Design Phase of the Project, should any questions arise as to impacts to environmental resources within the
Project limits, the appropriate agency will be contacted and all issues will be addressed accordingly.
HUMMOC
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Legend
Wastewater Pipes
D FORCE MAIN
D LOW PRESSURE
DD OVERFLOW PIPE
D GRAVITY MAIN, 4"
D GRAVITY MAIN, 6"
D GRAVITY MAIN, 8"
D GRAVITY MAIN, 10"
D GRAVITY MAIN, 12"
D GRAVITY MAIN, 15"
D GRAVITY MAIN, 18"
D GRAVITY MAIN, 20"
D GRAVITY MAIN, 24"
D GRAVITY MAIN, 30"
D GRAVITY MAIN, Unknown Diam.
Proposed Sewer
Impervious Cover
Pond
Wetland
COMPREHENSIVE WASTEWATERMANAGEMENT PLAN UPDATETOWN OF NANTUCKET, MA
HUMMOCK SOUTH NEEDS AREACONCEPTUAL LAYOUT
FIGURE 3-17
SCALE:
DATE: NOV. 2013 JOB NO.: 225139
DOC: ConceptLayout.MXD
DRAWN BY: JSM SOURCE: MassGIS & Town
1 inch = 750 feet
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.
Legend
Wastewater Pipes
D FORCE MAIN
D LOW PRESSURE
DD OVERFLOW PIPE
D GRAVITY MAIN, 4"
D GRAVITY MAIN, 6"
D GRAVITY MAIN, 8"
D GRAVITY MAIN, 10"
D GRAVITY MAIN, 12"
D GRAVITY MAIN, 15"
D GRAVITY MAIN, 18"
D GRAVITY MAIN, 20"
D GRAVITY MAIN, 24"
D GRAVITY MAIN, 30"
D GRAVITY MAIN, Unknown Diam.
Proposed Sewer
Impervious Cover
Pond
Wetland
Town Sewer District
COMPREHENSIVE WASTEWATERMANAGEMENT PLAN UPDATETOWN OF NANTUCKET, MA
MIACOMET NEEDS AREACONCEPTUAL LAYOUT
FIGURE 3-18
SCALE:
DATE: NOV. 2013 JOB NO.: 225139
DOC: ConceptLayout.MXD
DRAWN BY: JSM SOURCE: MassGIS & Town
1 inch = 750 feet
DD D
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.
Legend
Wastewater Pipes
D FORCE MAIN
D LOW PRESSURE
DD OVERFLOW PIPE
D GRAVITY MAIN, 4"
D GRAVITY MAIN, 6"
D GRAVITY MAIN, 8"
D GRAVITY MAIN, 10"
D GRAVITY MAIN, 12"
D GRAVITY MAIN, 15"
D GRAVITY MAIN, 18"
D GRAVITY MAIN, 20"
D GRAVITY MAIN, 24"
D GRAVITY MAIN, 30"
D GRAVITY MAIN, Unknown Diam.
Proposed Sewer
Impervious Cover
Pond
Wetland
Town Sewer District
COMPREHENSIVE WASTEWATERMANAGEMENT PLAN UPDATETOWN OF NANTUCKET, MA
MONOMOY NEEDS AREACONCEPTUAL LAYOUT
FIGURE 3-19
SCALE:
DATE: NOV. 2013 JOB NO.: 225139
DOC: ConceptLayout.MXD
DRAWN BY: JSM SOURCE: MassGIS & Town
1 inch = 750 feet
DDDDDD
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.
Legend
Wastewater Pipes
D FORCE MAIN
D LOW PRESSURE
DD OVERFLOW PIPE
D GRAVITY MAIN, 4"
D GRAVITY MAIN, 6"
D GRAVITY MAIN, 8"
D GRAVITY MAIN, 10"
D GRAVITY MAIN, 12"
D GRAVITY MAIN, 15"
D GRAVITY MAIN, 18"
D GRAVITY MAIN, 20"
D GRAVITY MAIN, 24"
D GRAVITY MAIN, 30"
D GRAVITY MAIN, Unknown Diam.
Proposed Sewer
Impervious Cover
Pond
Wetland
Town Sewer District
COMPREHENSIVE WASTEWATERMANAGEMENT PLAN UPDATETOWN OF NANTUCKET, MA
SHIMMO NEEDS AREACONCEPTUAL LAYOUT
FIGURE 3-20
SCALE:
DATE: NOV. 2013 JOB NO.: 225139
DOC: ConceptLayout.MXD
DRAWN BY: JSM SOURCE: MassGIS & Town
1 inch = 750 feet
Town of Nantucket (#225139.00)3-47 Woodard & Curran
Final CWMP Update Report Volume I October 2014
3.13.2.9 Town Sewer District
The Town was evaluated and identified in the 2004 Phase I Report as long-term unsustainable with the current on-
site wastewater disposal systems or simply a “Needs Area” and maintains this determination in this CWMP Update.
This was due not only to its proximity in relation to the Nantucket Harbor Watershed delineation, but, also, based on
qualifying criteria as detailed in the 2004 Phase I Report. The majority of the Town’s Sewer District Area properties
are currently connected to the Town’s municipal sewer system that connects to the Surfside WWTF. Gravity sewers
and pump stations collect and convey the wastewater to the Surfside WWTF for treatment and disposal. The
Recommended Plan under is for the remaining unsewered lots to be connected to the existing collection system.
3.13.2.9.1 Environmental Impact
This Needs Area is overlain by NHESP. This area is almost entirely serviced by municipal sewer with no negative
environmental impact. Based on the above-referenced information, no environmental impact with the planning level
concept is foreseen. All proposed new infrastructure is detailed as in existing, pre-disturbed right of ways and/or
roadways. There is a significant portion of this geographic area currently included within the approved Town Sewer
District serviced by municipal sewer with infrastructure that currently is active and can be utilized to connect
additional areas proposed in this Needs Area. In areas proposed and conducive to directional drilling, the use of
directional drilling eliminates many potential threats to environmental resources. Conventional Gravity Sewers will be
designed within existing right of ways and/or roadways to eliminate any threat to environmental resources. During the
Final Design Phase of the Project, should any questions arise as to impacts to environmental resources within the
Project limits, the appropriate agency will be contacted and all issues will be addressed accordingly.
3.13.2.10 Town WPZ
The Town Wellhead Protection Zone (WPZ) is a Needs Area based on its geographic location adjacent to the Town’s
Potable Water Supply. The majority of the WPZ is connected via gravity sewers to the existing Surfside Collection
System and is treated and disposed of at the Surfside Wastewater Treatment Facility. The remaining Town WPZ
Study Area is serviced through on-site wastewater disposal systems. At this time, the Recommended Plan is for
continued use of on-site wastewater disposal systems with oversight from the Town under a Septage Management
Plan. This recommendation is maintained in this CWMP Update. However, the Town should not allow any type of
variances to current Title 5 rules and regulations and/or Local regulations that could present a compromise to the
protection and preservation of the water supply and should establish a stringent monitoring program of all on-site
wastewater disposal systems in this Study Area. If it is determined that the public water supply is being or could be
subject to compromise, it is recommended that all potential impacts from unsewered lots be eliminated by connecting
to the existing collection system at Surfside.
3.13.2.10.1 Environmental Impact
This Needs Area is overlain by NHESP. This geographic area supports the Town’s Wellhead Protection Zone. Based
on the above-referenced information, no environmental impact with the planning level concept is foreseen. Any
potential environmental impact, specifically impacts to public water supplies, must be addressed immediately. There
is a significant portion of this geographic area currently included within the approved Town Sewer District serviced by
municipal sewer with infrastructure that currently is active and can be utilized to connect additional areas if needed in
this Needs Area. In areas proposed and conducive to directional drilling, the use of directional drilling eliminates
many potential threats to environmental resources. Conventional Gravity Sewers will be designed within existing right
of ways and/or roadways to eliminate any threat to environmental resources. During the Final Design Phase of the
Project, should any questions arise as to impacts to environmental resources within the Project limits, the appropriate
agency will be contacted and all issues will be addressed accordingly.
Town of Nantucket (#225139.00)3-48 Woodard & Curran
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3.13.2.11 PLUS
These parcels are various areas either within or directly abutting the Town Sewer District that for one reason or
another were left out of the Town Sewer District in error. Most are sandwiched within the existing sewer or are either
at the beginning or end of currently sewered streets. Most either immediately abut infrastructure or are in close
proximity of collection system components and can be connected without extraneous effort.
3.13.2.11.1 Environmental Impact
These miscellaneous parcels are overlain by NHESP. Based on the above-referenced information, no environmental
impact with the planning level concept is foreseen. These individual parcels are currently within existing sewer
infrastructure or in very close proximity to same and can be connected without any environmental impact. During the
Final Design Phase of the Project, should any questions arise as to impacts to environmental resources within the
Project limits, the appropriate agency will be contacted and all issues will be addressed accordingly.
Refer to Figure 3 -9 that details the proposed Nantucket Surfside Wastewater Collection System.as described in the
above paragraphs.
Study Areas Recommended for Septage Management Plan Including Areas Managed with3.13.3
Innovative / Alternative Systems
These 2004 Study Areas were re-evaluated in this CWMP Update and while not considered as areas needing an off-
site wastewater solution in 2004 or 2013, they abut Nantucket Harbor in various locations and contribute in various
manners to the Nitrogen loading documented in the MEP Report. Based on additional studies completed by SMAST
on scenarios in the Harbors to reduce nitrogen loading to meet established TMDLS, sewering these areas did not
serve to contribute to the reduction effort. It has been determined that a more cost effective approach to the Nitrogen
reduction be had through other contributors-fertilizer, stormwater and future build out. These efforts will supplement
the structured solutions being planned such as sewering, raising the jetties to afford a deeper tidal exchange and
dredging. This CWMP Update is making recommendations to limit additional, future nitrogen loading with current and
build-out conditions within the Adaptive Management Plan contained herein.
The following Study Areas are recommended for oversight under the Town’s Septage Management Plan. As part of
the overall Adaptive Management Plan include herein, this Report is also recommends consideration for future
management utilizing Innovative / Alternative systems due to each area’s geographic locations within Nitrogen-
sensitive embayments as detailed in the MEP Reports. I/A systems will afford a higher nutrient reduction, up to 50
percent of TN, than a conventional Title 5 system is able to do.
3.13.3.1 Polpis
The Polpis Study Area was evaluated in the 2004 CWMP and recommended to maintain on-site wastewater disposal
under the Town’s Septage Management Plan unless the MEP report being completed at the time of the 2004 Report
recommended otherwise (The 2004 CMP was completed before the MEP Study was finished). This CWMP Update
maintains this determination with a few exceptions based on the results of the Nantucket and Polpis Harbors MEP.
Because Polpis Harbor is included in the MEP and has a TMDL established in the Harbor with a threshold water
quality to meet, it is recommended that future build out, as well as future repairs and/or upgrades to current Title 5
systems be mandated with an I/A system in order to reduce nitrogen loading to the Watershed. The Polpis Study
Area is a high priority in terms of requiring attention due its location in proximity to and potential impact to not only
Polpis Harbor, but Nantucket Harbor from the existing conventional on-site wastewater disposal systems.
The Town, under the auspices of the Septage Management Plan, will be able to monitor all on-site wastewater
disposal systems, both conventional and I/A in order to evaluate future needs based on water quality results.
Town of Nantucket (#225139.00)3-49 Woodard & Curran
Final CWMP Update Report Volume I October 2014
3.13.3.2 Pocomo
The Pocomo Study Area was evaluated in the 2004 CWMP and recommended to maintain on-site wastewater
disposal under the Town’s Septage Management Plan unless the MEP report being completed at the time of the
2004 Report recommended otherwise (The 2004 CMP was completed before the MEP Study was finished). This
CWMP Update maintains this determination with a few exceptions based on the results of the Nantucket and Polpis
Harbors MEP. Due to two TMDLs established in this geographic area as a result of the completed Nantucket and
Polpis Harbor MEP and the location of this Study area in the upper reaches of the Harbor, it is necessary to look
towards future build out conditions with respect to nutrient loading. There are two TMDLs established in this area,
one in Nantucket Harbor and the second in Polpis Harbor. In order to meet and maintain the threshold water quality,
it is recommended that future build out, as well as future repairs and/or upgrades to current Title 5 systems be
mandated with an I/A system in order to reduce nitrogen loading to the Watershed. The Pocomo Study Area is a high
priority in terms of requiring attention due its location in proximity to and potential impact to not only Polpis Harbor,
but Nantucket Harbor from the existing conventional on-site wastewater disposal systems.
The Town, under the auspices of the Septage Management Plan, will be able to monitor all on-site wastewater
disposal systems, both conventional and I/A in order to evaluate future needs based on water quality results.
3.13.3.3 Wauwinet
The Wauwinet Study Area was evaluated in the 2004 CWMP and recommended to maintain on-site wastewater
disposal under the Town’s Septage Management Plan unless the MEP report being completed at the time of the
2004 Report recommended otherwise (The 2004 CMP was completed before the MEP Study was finished). This
CWMP Update maintains this determination with a few exceptions based on the results of the Nantucket and Polpis
Harbors MEP. Due to two TMDLs established in this geographic area as a result of the completed Nantucket and
Polpis Harbor MEP and the location of this Study area in the upper reaches of the Harbor, it is necessary to look
towards future build out conditions with respect to limiting additional nutrient loading. There are two TMDLs
established in this area, one in Nantucket Harbor and the second in Polpis Harbor. In order to meet and maintain the
threshold water quality, it is recommended that future build out, as well as future repairs and/or upgrades to current
Title 5 systems be mandated with an I/A system in order to reduce nitrogen loading to the Watershed. The Pocomo
Study Area is a high priority in terms of requiring attention due its location in proximity to and potential impact to not
only Polpis Harbor, but Nantucket Harbor from the existing conventional on-site wastewater disposal systems.
3.13.3.4 Surfside
The Surfside Study Area was evaluated in the 2004 CWMP as long-term sustainable with the current on-site
wastewater disposal systems and maintains this determination in this CWMP Update. Based on an update of the
2004 criteria and regulatory drivers, this Study Area continues to be recommended for on-site wastewater
management. Therefore, the Final Recommended Plan is continued use of on-site wastewater disposal systems with
oversight from the Town under a Septage Management Plan.
3.13.3.5 Tom Nevers – Low Density
The Tom Nevers-Low Density Study Area was evaluated in the 2004 CWMP as long-term sustainable with the
current on-site wastewater disposal systems and maintains this determination in this CWMP Update. Based on an
update of the 2004 criteria and regulatory drivers, this Study Area continues to be recommended for on-site
wastewater management. Therefore, the Final Recommended Plan is continued use of on-site wastewater disposal
systems with oversight from the Town under a Septage Management Plan.
Town of Nantucket (#225139.00)3-50 Woodard & Curran
Final CWMP Update Report Volume I October 2014
3.13.3.6 Tom Nevers-High Density
The Tom Nevers-High Density Study Area was evaluated in the 2004 CWMP as long-term sustainable with the
current on-site wastewater disposal systems and maintains this determination in this CWMP Update. Based on an
update of the 2004 criteria and regulatory drivers, this Study Area continues to be recommended for on-site
wastewater management. Therefore, the Final Recommended Plan is continued use of on-site wastewater disposal
systems with oversight from the Town under a Septage Management Plan.
3.13.3.7 Quidnet
The Quidnet Study Area was evaluated in the 2004 CWMP as long-term sustainable with the current on-site
wastewater disposal systems and maintains this determination in this CWMP Update. Based on an update of the
2004 criteria and regulatory drivers, this Study Area continues to be recommended for on-site wastewater
management. Therefore, the Final Recommended Plan is continued use of on-site wastewater disposal systems with
oversight from the Town under a Septage Management Plan. The Quidnet Area is a high priority in terms of requiring
attention due its location in proximity to and potential impact to Sesachacha Pond from on-site wastewater disposal
systems. Sesachacha Pond is currently listed on the State’s 303(d) list and based on the last three years of water
quality results that are meeting and/or exceeding thresholds levels set in the MEP, will be petitioned to have the state
remove the Pond from the impaired waters list. These improved water quality tests are the results of successful semi-
annual breaches that afford the Pond a solid flushing of the entire system.
Based on an update of the 2004 criteria and regulatory drivers, this Study Area continues to be recommended for on-
site wastewater management. Therefore, the Final Recommended Plan is continued use of on-site wastewater
disposal systems with oversight from the Town under a Septage Management Plan.
3.13.3.8 Siasconset
The Siasconset Study Area was not included in the CWMP Update Scope of Work.
3.13.3.9 Remaining Island
The Remaining Island Area, all areas not encompassed in the above-referenced Needs and Study Areas, was
evaluated in the 2004 CWMP as long-term sustainable with the current on-site wastewater disposal systems and
maintains this recommendation in this CWMP Update. After updating the criteria utilized in 2004, including Board of
Health records, there was no additional area within this general geographic area that stood out as needing a closer
evaluation of wastewater management other than those areas incorporated. Therefore, the Final Recommended Plan
is continued use of on-site wastewater disposal systems with oversight from the Town under a Septage Management
Plan.
Table 3-4 presents the Final Recommended Plan for the proposed Surfside Wastewater Collection System, including
estimated infrastructure needs and cost estimates.
Figure 3-21 details the Capital Improvements Plan as detailed in this CWMP Update. Refer to Appendix I for back-up
details.
Refer to Figure 3-22 for a map of the Final Recommended Plan.
Town of Nantucket (#225139.00)3-51 Woodard & Curran
Final CWMP Update Report Volume I October 2014
Table 3-4: Summary of Surfside Wastewater Collection System Recommended Plan
Need Area Proposed Recommendation
Linear Feet of
Sewer
Number of New
Pump Stations
Opinion of
Budgetary Cost
Madaket Low-pressure sewer and new pump
station
40,700 sewer
16,800
forcemain
1 $42,650,000
(includes
forcemain)
Warren’s
Landing
Low-pressure sewer and pump station 6,300 $4,536,000
Somerset Gravity and/or low-pressure sewer 20,500 $14,760,000
Hummock
North
Gravity and/or low-pressure sewer 45,800 1 (potential)$34,226,000
Hummock
South
Gravity and/or low -pressure sewer 32,800 1 (potential)$24,866,000
Miacomet Gravity and/or low -pressure sewer 27,100 1 (potential)$20,762,000
Shimmo Low pressure sewer 32,600 $23,472,000
Monomoy Low pressure and/or gravity sewer 30,800 $23,426,000
PLUS Connect into existing infrastructure in TSD
where available. Work with the DPW on
areas that need capital investments.
TBD $2,518,000
Town Connect remaining unsewered lots to the
existing collection system.
TBD TBD
Town WPZ Continued use of on-site wastewater
disposal systems with oversight from the
Town under a Septage Management
Plan.
TBD TBD
Polpis Continued use of on-site wastewater
disposal systems with future I/A mandate
for build out. Oversight from the Town
under a Septage Management Plan.
TBD
Pocomo Continued use of on-site wastewater
disposal systems with future I/A mandate
for build out. Oversight from the Town
under a Septage Management Plan.
TBD
Wauwinet Continued use of on-site wastewater
disposal systems with future I/A mandate
for build out. Oversight from the Town
under a Septage Management Plan.
TBD
Surfside Continued use of on-site wastewater
disposal systems with oversight from the
Town under a Septage Management
Plan.
TBD
Tom Nevers –
Low Density
Continued use of on-site wastewater
disposal systems with oversight from the
Town under a Septage Management
Plan.
TBD
Tom Nevers –
High Density
Continued use of on-site wastewater
disposal systems with oversight from the
Town under a Septage Management
Plan.
TBD
Quidnet Continued use of on-site wastewater
disposal systems with oversight from the
TBD
Town of Nantucket (#225139.00)3-52 Woodard & Curran
Final CWMP Update Report Volume I October 2014
Need Area Proposed Recommendation
Linear Feet of
Sewer
Number of New
Pump Stations
Opinion of
Budgetary Cost
Town under a Septage Management
Plan.
Remaining
Island
Continued use of on-site wastewater
disposal systems with oversight from the
Town under a Septage Management
Plan.
TBD
Siasconset Not evaluated in this CWMP Update
Scope of Work
Figure 3-21
2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036
SurfsideTom Nevers High DensityTom Nevers Low DensityTown-WPZSeptage Management Plan Includes System Pumping Pocomo 3,578,000$125,000$129,000$133,000$137,000$141,000$145,000$149,000$153,000$158,000$163,000$168,000$173,000$178,000$183,000$188,000$194,000$200,000$206,000$212,000$218,000$225,000$PolpisQuidnetWauwinetRemainder of Island
Natural Resources Department
Annual Water Quality Program Townwide Sampling Program 807,600$35,000$35,000$35,000$36,100$36,100$36,100$37,200$37,200$37,200$38,400$38,400$38,400$39,600$39,600$39,600$40,800$40,800$40,800$42,100$42,100$42,100$
Somerset 14,760,000$1,476,000$13,284,000$
Design 1,476,000$Construction 13,284,000$
Madaket/Warrens Landing 47,186,000$4,718,600$42,467,400$Design 4,718,600$Construction 42,467,400$
Monomoy/Unconnected TSD Parcels*23,426,000$2,342,600$21,083,400$Design*2,342,600$Construction*21,083,400$
Hummock Pond North 34,226,000$3,422,600$30,803,400$Design 3,422,600$Construction 30,803,400$
Hummock Pond South 24,866,000$2,486,600$22,379,400$Design 2,486,600$
Construction 22,379,400$
Shimmo 23,472,000$2,347,200$21,124,800$
Design 2,347,200$
Construction 21,124,800$
Miacomet 20,762,000$2,076,200$18,685,800$
Design 2,076,200$
Construction 18,685,800$
Nantucket PLUS Parcels 10,116,000$
Pump Station Assessment,Improvements, End of Life Replacement 11,412,500$62,500$2,100,000$2,500,000$1,250,000$1,250,000$1,250,000$1,250,000$1,750,000$
Infrastructure Improvements -Downstream Improvements 16,990,000.00$8,076,000$3,514,000$5,400,000$
Surfside WWTF Improvements-FutureCapacity 1,204,000.00$1,204,000$
Surfside WWTF Improvements -
Energy Efficiency 154,000.00$154,000$
229,099,500$3,081,500$26,267,600$48,517,000$28,781,500$2,549,300$21,330,900$2,697,800$25,094,600$1,470,200$3,649,000$31,034,800$236,400$2,318,800$18,933,400$1,502,600$1,509,800$265,800$1,521,800$2,029,100$285,100$292,100$
Total 20-Year Capital Improvements Plan By Department Total `
Department of Public Works 229,099,500$
Board Of Health 3,578,000$
Natural Resources Department 807,600$
233,485,100$
Comprehensive
Wastewater
Management Plan
25,000$25,000$Department of Public WorksCWMP Implementation Adaptive Management Plan - TMDL's, Oversight and Management 525,000$
Infrastructure Expansion
TOWN OF NANTUCKET
DEPARTMENT OF PUBLIC WORKS
CAPITAL IMPROVEMENT PROGRAM FY 2016-2036
FOR CWMP AND EVALUATION AND MAPPING RECOMMENDATIONS
Estimated Project
Cost
25,000$25,000$
Board of HealthOn-Site Solution
Department of Public WorksOff-Site Solution
25,000$25,000$25,000$25,000$25,000$25,000$25,000$25,000$25,000$25,000$25,000$25,000$25,000$25,000$25,000$25,000$
SRF 0% Loan Duration
25,000$
Page 1 Copy of Nantucket CWMP Update CIP 2016 - 2036_jk edits
Town of Nantucket CWMP Update
AREAS RECOMMENDED FOR SEWER SERVICE
MADAKET
Drivers:
•Draft TMDL – Water Quality
•Madaket Harbor Watershed
•Small, Dense Lots
•Severe Soils
•Severe Groundwater
•Inability to Meet Title 5
•Inability to Meet Local BOH Regs
•Private Water Supply
Recommendation:
Municipal Sewer at Surfside WWTF
WARRENS LANDING
Drivers:
•Draft TMDL – Water Quality
•Madaket Harbor Watershed
–GW Flow Towards Hither Creek Water
Quality
•Small, Dense Lots
Recommendation:
Municipal Sewer at Surfside WWTF
HUMMOCK POND SOUTH
Drivers:
•Pending TMDL – Water Quality
•Hummock Pond Watershed
•Small, Dense Lots
•Severe Soils
•Inability to Meet Title 5
•Inability to Meet Local BOH Regs
•Private Water Supply
Recommendation:
Municipal Sewer at Surfside WWTF
HUMMOCK POND NORTH
Drivers:
•Pending TMDL – Water Quality
•Hummock Pond Watershed
–Head of Hummock
Recommendation:
Municipal Sewer at Surfside WWTF
SOMERSET
Drivers:
•Small, Dense Lots
•Severe Soil and Groundwater Conditions
•Inability to Meet Title 5
•Private Water Supply
Recommendation:
Municipal Sewer at Surfside WWTF
MIACOMET
Drivers:
•Water Quality
•Small, Dense Lots
•Severe Soil and Groundwater Conditions
Recommendation:
Municipal Sewer at Surfside WWTF
MONOMOY
Drivers:
•TMDL – Water Quality
•Nantucket Harbor Watershed
–Polpis Harbor TMDL
•Severe Soil and Groundwater Conditions
Recommendation:
Municipal Sewer at Surfside WWTF
SHIMMO
Drivers:
•TMDL – Water Quality
•Nantucket Harbor Watershed
–Polpis Harbor TMDL
•Severe Soil and Groundwater Conditions
Recommendation:
Municipal Sewer at Surfside WWTF
TOWN WPZ
Drivers:
•Town’s Wellhead Protection
Recommendation:
Municipal Sewer at Surfside WWTF IF IMPACTED
TOWN SEWER DISTRICT UNSEWERED
Drivers:
•TMDL – Water Quality
•Nantucket Harbor Watershed
–Polpis Harbor TMDL
Recommendation:
Municipal Sewer at Surfside WWTF
SPECIAL AREAS RECOMMENDED FOR SEWER AREAS RECOMMENDED FOR SEPTAGE MANAGEMENT PLAN
Polpis Pocomo Wauwinet
Quidnet Surfside
Tom Nevers High Density Tom Nevers Low Density
December 2013
Town of Nantucket (#225139.00)3-55 Woodard & Curran
Final CWMP Update Report Volume I October 2014
Ocean Outfall Alternative3.13.4
This section describes the opportunities and constraints an Ocean Outfall discharge option would have for Nantucket.
The Massachusetts Ocean Sanctuaries Act at Massachusetts General Laws (M.G.L), Chapter 132A, sections 12A
through 16E & 18, (and as amended by the Ocean Sanctuaries Act of 2008), and at 302 Code of Massachusetts
Regulations (CMR) 5:00 (“The Act”). The Act defines the five Ocean Sanctuaries in Massachusetts waters as follows:
Cape Cod8.
Cape Cod Bay9.
Cape and Islands10.
North shore11.
South Essex Ocean12.
These areas include the majority of the state waters in the areas with an exception of an areas east of Boston
Harbor. These boundaries are set by statutory regulation under M.G.L. and the CMR cited above and jurisdiction
includes any activity that could endanger the ecology or appearance of the Ocean Sanctuaries. The Massachusetts
Office of Coastal Zone Management is the state agency in charge of implementing and enforcing the Act. The details
in the Act specifically prohibit Ocean Outfalls and more specifically the discharge of municipal waste in Cape Cod,
Cape Cod Bay and the Cape and Island Sanctuaries.
The only allowable activities are described and detailed direct from the Regulations at CMR 5.08, include:
“(1) Except in the Cape Cod Ocean Sanctuary, and provided that all applicable certificates,
licenses, permits and approvals required by federal, state or local law have been obtained and
provided further that such activities, uses and facilities shall not be undertaken or located except
in compliance with any applicable general or special statutes, rules, regulations or order lawfully
promulgated, the planning, construction, reconstruction, operation or maintenance of an
industrial liquid coolant discharge or intake system and any activity, use or facility associated
with the generation, transmission or distribution of electrical power shall be permitted. All such
activities shall be prohibited in the Cape Cod Ocean Sanctuary.
(2) With the exception of municipal wastewater treatment facilities and discharges (see 302
CMR 5.08(9)), the operation and maintenance of any municipal, commercial or industrial facility
or discharge existing as of the following dates, which are the effective dates of the applicable
original ocean sanctuaries acts, shall be allowed so long as such facility or discharge has been
approved and licensed by the appropriate federal and state agencies:
Cape Cod Ocean Sanctuary July 15, 1970
Cape Cod Bay and Cape and
Islands Ocean Sanctuaries December 8, 1971
North Shore Ocean Sanctuary June 27, 1972
South Essex Ocean Sanctuary December 30, 1976
No municipal, commercial or industrial facility or discharge built or occurring in any ocean
sanctuary after those dates shall be permitted, except as specifically allowed elsewhere in
302 CMR 5.08(1) through (9).
(3) The laying of any electric or telephone cable shall be allowed if approved by the Department
of Public Utilities.
(4) Any project authorized under M.G.L. c. 91, including channel and shore protection projects
Town of Nantucket (#225139.00)3-56 Woodard & Curran
Final CWMP Update Report Volume I October 2014
and navigation aids, shall be allowed, but only if it is not otherwise prohibited by 302 CMR 5.00,
if it has received all required federal and/or state approvals and if the approving agency also finds
that the project is one of public necessity and convenience.
(5) Any improvement to permitted structures or uses that is not specifically prohibited by
M.G.L. c.132A §§ 14, 15, and 18 shall be allowed so long as it does not change or extend such
structures or uses and it is otherwise approved by appropriate state and federal agencies. Such an
improvement may change or extend such structures or uses if it is specifically permitted by
302 CMR 5.08(1) through (9) and may include maintenance and repairs to such structures or
uses. Any such improvements shall be consistent with M.G.L. c. 132A, §§14, 15 and 18.
(6) The harvesting and propagation of all finfish and shellfish may be allowed if the Department
and the Department of Fisheries, Wildlife and Recreational Vehicles are satisfied that such
activities will be carried out in accordance with sound conservation practices.
(7) Any educational and/or scientific project of a temporary nature may be allowed
notwithstanding any restriction of 302 CMR 5.08, if it is otherwise approved by all applicable
state agencies.
(8) The extraction of sand and gravel from the seabed and subsoil of any ocean sanctuary shall
be allowed if such sand and gravel is to be used for a shore protection or beach restoration
project; but such project must be approved by the Department of Environmental Quality
Engineering. In the case of a shore protection project, it must, in addition, be found to be of
public necessity and convenience by the Department of Environmental Quality Engineering and
any other state agency from which a permit is required.
302 CMR: DEPARTMENT OF ENVIRONMENTAL MANAGEMENT
12/1/93 302 CMR - 37
5.08: continued
(9)(a) In the Cape Cod Ocean Sanctuary, the Cape Cod Bay Sanctuary, and the Cape and
Island Ocean Sanctuary, no municipal wastewater treatment discharge into the ocean
sanctuary shall be allowed.
(b) In the South Essex Ocean Sanctuary, such a discharge shall be allowed only if it is:
1. the only feasible alternative to a water pollution problem;
2. consistent with the intention and purpose of M.G.L. c. 132A, § 13 through 16 and 18;
and
3. approved and licensed by the federal and state agencies that have jurisdiction over the
facility or discharge at the time it is proposed to be built.
The decision as to whether a proposed discharge is the only feasible alternative shall be
made by the Department in consultation with other appropriate state agencies.
(c) In the North Shore Ocean Sanctuary such a discharge shall be allowed only if:
1. all the requirements of 302 CMR 5.08(9)(b) are met;
2. construction of the facility was commenced prior to January 1, 1978 or the
municipality proposing such a discharge was awarded a federal or state grant for
construction of the facility prior to January 1, 1978;
3. the waste from such a discharge has been treated by the best practical means; and
4. the discharge is in accordance with plans that have been developed under the
provisions of M.G.L. c. 21, § 27(10). Such plans are subject to approval of the Division of Water Pollution Control
after a public hearing.”
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As noted above, The Act prohibits or in some cases, severely restricts the discharge of municipal wastewater into
identified Ocean Sanctuaries. The areas surrounding Nantucket are included in their entirety as located within an
Ocean Sanctuary. Any attempt now or in the near future to develop this alternative would be fruitless until the
Regulations are changed or amended to allow such use by Nantucket. This alternative should, however, continue to
be included on the list of alternative opportunities as Ocean Outfalls are the topic of current discussions in
Massachusetts, not only in southeastern Massachusetts, Cape and Island communities, but the Regulatory
community as well. It is recommended that Nantucket stay involved in these discussions.
The Ocean Outfall alternative involves the siting, constructing and operating of an underground pipe that carries
highly treated effluent from a Wastewater Treatment facility to the marine waters off Nantucket’s shoreline, which
would have the least impact on any of the Town’s drinking water supplies, embayment areas, as well as
environmental resources that blanket the Island. When highly treated and properly sited well outside of near shore
environmentally sensitive areas, this alternative will have minimal, if any, impact to the marine environment. In
comparison to how the Surfside WWTF currently discharges through 15 sand beds adjacent to the south shore of
Nantucket, an Ocean Outfall in this location would avoid the environmental impacts that required mitigation with the
current operations. There were multiple rare species impacted when the sand discharge beds were planned and
cited requiring Nantucket to prepare several conservation management plans to mitigate the loss or disruption to a
number of endangered species in the location. The groundwater discharge, under MassDEP jurisdiction, currently
flows through the ground in one of fifteen open sand beds directly to the ocean on the south shore of the Island.
Figure 3-23, Existing Surfside WWTF Discharge Beds, details the current operation.
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If an Ocean Outfall were to replace the groundwater discharge at this location, the highly treated effluent would flow
far below the surficial areas where the impacts exist – the rare and endangered species under Natural Heritage and
Endangered Species, archaeological/historical resources under the Massachusetts Historical Commission
jurisdiction, and beyond the immediate shoreline and protected coastal barrier beaches - thus less impact to the
overall area. The current groundwater discharge via open sand beds travels directly to the ocean waters on the south
shore with no recharge to any of the Town’s aquifers. With proper siting of an Outfall further offshore, there would be
far less impact to the marine waters in this location. In addition, an Outfall in this location would provide the Town
with the additional flow it needs to address the Needs Areas (areas identified as needing an off-site solution) from the
CWMP. Most Needs areas are located within estuaries and or embayments areas noted in the Massachusetts
Estuaries Program Reports as contributing nitrogen degradation to the water resources. As it stands now, the Town
has the capacity to treat the Needs Areas wastewater at the Surfside WWTF, but is limited in its MassDEP
groundwater Discharge Permit to discharge in the current location. Table 3-5 below outlines the opportunities and
constraints with this alternative.
Table 3-5: Ocean Outfall Opportunities and Constraints
OPPORTUNITIES CONSTRAINTS
Less land area needed for discharge Currently not permitted under the Massachusetts Ocean
Sanctuaries Act
Discharge is outside of environmentally sensitive areas Costs may be high due to extensive permitting, siting and
actual construction needs.
Fits current space and location existing at Surfside
Nantucket Town Counsel was a guest speaker at the May 24, 2011; “Ocean Outfall Symposium” hosted by the
Waquoit Bay Reserve, and eloquently summarized the process needed to obtain a variance under the current
Regulations. This presentation is included in Appendix J for review and consideration.
Therefore, while this is considered an option for consideration, it clearly needs to stay on the table for future
discussions. There are several Cape communities spearheading an effort to change the current Regulation and it is
recommended that Nantucket closely follow the activities as they happen.
3.14 ENVIRONMENTAL REVIEW
Environmental Impacts3.14.1
When determining the recommended plan for each Needs Area, it is important to take into consideration, identify,
and mitigate any environmental impacts. Massachusetts’s Executive Order 385 was signed into law by then
Governor William F. Weld and states in general that the citizens of Massachusetts have a constitutional "right to
clean air and water and the natural, scenic, historic, and aesthetic qualities of their environment.” It also states that
the “conflict between environmental quality and economic activity ultimately puts at risk environmental resources as
well as economic opportunity; thus threatening, for example, public water supplies, clean air, swimmable and fishable
waters, flood protection, open space, agricultural lands, historic sites, and community character; but also affecting the
timely provision of needed infrastructure, financial assistance and regulatory approvals for appropriately sited and
designed development.” With the provisions of Executive Order 385 in effect, the conflicts of the environment should
and can be avoided to a great extent through proactive and coordinated planning oriented towards both resource
protection and sustainable economic activity, known as growth management, or basically sustainable development.
Therefore, Executive Order 385 is the State’s direction for all planning, such as this CWMP, to account for
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sustainable development in the crafting of this draft recommended plan. While this Report is not yet in any formal EIR
filing, the evaluation was completed in order to distinguish any areas of environmental impact and provide mitigation
measures for moving forward.
The following section presents potential environmental impacts and associated mitigation measures of the
Recommended Plan, in accordance with Executive Order 385.
3.14.1.1 Direct Impacts
3.14.1.1.1 Historical, Archaeological, Cultural, Conservation and Recreation
The proposed work contained in the scope of this project is not anticipated to have any major impacts on historical,
archaeological or cultural resources. Nantucket is known for its historical and archaeological resources. In the May
14, 2004 MEPA Certificate on the Final CWMP/Final EIR, MEPA suggested that as the Town progresses further with
the proposed Madaket WWTF, it work with the MHC and NHESP as both agencies commented on either potential or
documented resources within the project area. The Town worked directly with both MHC and NHESP with permits to
conduct due diligence at the Madaket site. The Town worked with the Massachusetts Historical Commission (MHC)
and PAL under a permit from MHC to complete an intensive survey, as the 2004 MEP Certificate stated, at the
proposed Madaket WWTF site, former FAA property, where the 2004 CWMP recommended the design and
construction of a WWTF and groundwater discharge. The Town contracted with PAL to complete both a walkover
and paper file assessment of the site and subsequently an intensive survey under permit with a scope of work
approved by MHC. The portion of the site that the Town was proposing to utilize, approximately 25 acres, was
evaluated with results showing no impact to historical or archaeological resources. The remaining portion of the site,
approximately, 67 acres, was not evaluated, as there was no proposed use.
The Town also worked under permit from NHESP to conduct an intensive botanical survey on the Madaket site as
stated in the 2004 MEPA Certificate. The botanical survey identified multiple plant and animal species contained
within this site and is fully documented in the 2013 Report that was subsequently filed with NHESP. The Town also
worked under permit with NHESP before the historical/archaeological survey was performed as this intensive survey
scope was to disturb the site with hand-digging in order to identify artifacts. The NHESP Permit mandated that a
botanist be present during the intensive survey to oversee that no areas of interest to NHESP were impacted. The
intensive survey was conducted during late spring 2013.
Copies of all NHESP and MHC communication and reports are included in Appendix G. The 2004 MEPA Certificate
is included in Appendix A.
During the course of this CWMP Update, this site (former FAA site) has been eliminated from consideration for the
wastewater utility as the Town is proposing to utilize the existing Surfside WWTF to service both Madaket and
Warrens Landing Needs Areas. With the former FAA site being eliminated from use, this no longer represents a
concern with MHC or the Natural Heritage and Endangered Species Program as this site was the main concern in
the 2004 MEPA Certificate.
The National Register of Historic Places/Massachusetts/Nantucket County online database, the following sites are
listed in Nantucket:
The Brant Point Light Station – Town location
The Jethro Coffin House – Town location
Sankaty Head Light - Siasconset
Nantucket Historic District – entire Town
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The first two above-noted registered historical sites are structures located in the Town District area. The third-noted
structure is located in Siasconset, which is not included in this CWMP Update. None of the first three are in any close
proximity to the project locations and will not be impacted with any portions of the proposed project. The fourth,
Nantucket Historic District, encompasses the entire Island. This area of historic interest is under the jurisdiction of the
Nantucket Historic District Commission, which oversees all activity on Island. At this point in the planning process,
there is no proposed impact as all infrastructure is either existing, as in the Surfside WWTF and collection system or
new proposed piping, which is planned to be constructed within existing right of ways that are pre-disturbed
roadways. The Town will work with both The MHC and the Nantucket Historic District Commission during the design
phase of the project to identify and mitigate, if necessary, any potential impact
Conservation and Recreation land includes lands with Conservation Restrictions and lands owned by the Department
of Conservation and Recreation, land under local Town Conservation jurisdiction, various private conservation
groups, US Fish and Wildlife and others. There is over 65 percent of Town land area under conservation
management of some type and these lands are within many of the project Needs Areas, but not impacted. The
methodology utilized to determine future wastewater flows excludes all conservation land, open space, agricultural
land, and all lands protected with land use restrictions. The State Land Use Code was used to determine future flows.
There will be no impact to these lands. In addition, no infrastructure is planned to run through any of these lands.
With directional drilling of sewer infrastructure in certain areas of the Town (Madaket and Warrens Landing), and
proposed construction of pipes and pump stations in existing, pre-disturbed right of ways/roadways, impacts to these
resources will be avoided.
When the Town moves towards implementation of design of the Final Recommended Plan included herein, it will
work with the necessary jurisdictions to ensure that all state, federal and local rules and regulations are adhered to.
3.14.1.1.2 Wetlands, Flood Plains, and Agricultural Lands
Implementation of the Recommended Plan may temporarily impact wetlands. No long term or permanent impacts to
wetlands are anticipated. There is potential for construction of sewer pipe and pump stations within the 100-foot
buffer zone and within wetland resource areas (including Riverfront Area, Bank, and land subject to flooding). The
design process will include a survey and wetlands flagging, and the collection systems will be designed in a manner
to avoid wetland resource areas and minimize proximity to wetlands where technically feasible.
Any impacts will be temporary and associated with construction of the collection system. Impacts will be mitigated by
erosion and sedimentation control during construction and by any other means deemed necessary by the local
Conservation Commission and MassDEP through the wetlands permitting process. The Massachusetts Stormwater
Management Standards and Handbook will be followed as necessary.
While this Report is based on conceptual design, the Final Design will determine the exact location, and if necessary,
design will include watertight appurtenances.
Based on the Land Use methodology, all Agricultural Preservation Restriction lands are eliminated from inclusion in
the project. The methodology utilized to determine future wastewater flows excludes agricultural land based on the
State Land Use Code. There will be no impact to agricultural lands.
Coordination of design and construction will be conducted with the Nantucket Conservation Commission and
local/regional Board of Health, to identify any wetlands or flood plain resource issues and identify any necessary
mitigation measures. In addition, the Town will work with the Conservation Commission to determine the need for
Requests for Determination of Applicability (RDAs) and Notice of Intents (NOIs) as the recommended plan
progresses.
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With the proposed directional drilling of sewer infrastructure, and locating of new infrastructure within existing right of
ways/roadways that are pre-disturbed, impacts will be avoided.
3.14.1.1.3 Zones of Contribution of Existing and Proposed Water Supply Sources
There are several sections of Needs Areas that are located within DEP Wellhead Protection Areas (approved Zones
IIs).
The Town Sewer District and the Monomoy Needs Area are partially located within Zone II wellhead
protection area. The Town WPZ Area is also within the Zone II.
There are no direct impacts anticipated to the wellhead protection areas, as majority of the sewer mains will be
installed within existing roadways. Sewers in the wellhead protection areas will be designed in accordance with DEP
requirements for such construction and will include stringent measures to guard against exfiltration of untreated
wastewater. Furthermore, steps will be taken to minimize indirect environmental impacts during preliminary design
and construction. See Figure 3-X for a map of Needs Areas and Zones of Contributions.
Refer to Figure 3-12 for Needs Areas and Zones of Contributions.
Removal of on-site wastewater disposal systems from the resource areas will benefit the environment and preserve
and protect the drinking water sources in these areas. As previously stated, most of the sewer mains will be
constructed within existing roadways, thereby minimizing potential environmental impacts. The installation and
connection of residences to a centralized wastewater collection system will divert wastewater from the public water
supply, having a beneficial impact to the groundwater quality within the wellhead protection area. The Town Sewer
District and Monomoy Needs Area both fall into the nitrogen-sensitive area within the Massachusetts estuaries
Project (MEP) where septic systems are contributing excessive loads to the embayment areas. Removal of these on-
site systems will contribute towards the nutrient reduction in the areas and serve to help meet the established Total
Maximum daily Loads (TMDLs) issued.
3.14.1.1.4 Surface and Groundwater Resources
No negative impacts associated with the recommended plan are anticipated to surface and groundwater resources.
The removal of on-site wastewater disposal systems from the Needs Areas will serve to reduce documented nutrient
loading to the water resources and serve to help meet established TMDLs. The MEP Reports have documented the
contribution of nutrients to both ground and surface water from on-site wastewater disposal systems in multiple areas
on Island, as well as the years of documented water quality testing through the Marine and Natural resources
Department. The project as proposed in this CWMP Update will help to restore water quality Island-wide.
There are a number of surface water bodies, harbors, embayments and estuaries located within Nantucket – many
the subject of the MEP. These include Nantucket Harbor, Polpis Harbor, Madaket Harbor, Long Pond, Sesachacha
Pond and Hummock Pond. Miacomet Pond, a fresh water pond, is also located in and around proposed project
areas.
Any potential impacts during construction will be mitigated by erosion and sedimentation control during construction
and by any other means deemed necessary by the local Conservation Commission and MassDEP through the
wetlands permitting process. Any construction within 200 feet of these waterbodies will be reviewed locally as
required by the Wetlands Protection Act and proper erosion and sedimentation control measures will be employed.
Portions of the proposed Project Area, as detailed above in the Zone II, are underlain by the Town’s Sole Source
Aquifer. Sewering these Needs Areas will help protect the water quality of the aquifer by removing failing and/or
improperly operating onsite wastewater disposal systems.
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Any impacts to these resources are positive with the Project as proposed and serve to meet established TMDLs.
3.14.1.1.5 Displacements of Households, Businesses, and Services
None of the recommended plan will cause displacement of households or businesses. Final design of sewer
infrastructure and pump station locations will be developed to prevent displacements of households, businesses and
services. There may be temporary disturbances during construction, but the Town will work to develop a plan to
notify any properties well in advance of the actual construction and work together to develop a plan that has the least
impact.
With directional drilling of sewer infrastructure, impacts will be avoided. All construction along major routes will have a
plan developed well before actual construction, including traffic mitigation. Seasonal occupation of the Island will also
be a consideration when developing construction schedules in order to mitigate traffic and interruption of businesses
and services. This is a normal task on Island and will be adhered to with all aspects of the Project as proposed.
The Town has a well-developed public outreach and communication plan during times of construction that is typical
of any work done on the Island. Communication will be well planned and orchestrated.
3.14.1.1.6 Noise Pollution, Air Pollution, Odor and Public Health Issues Associated with
Construction and Operation
There may be temporary noise pollution and air pollution (dust) during construction involved with the Recommended
Plan. Limiting the hours and the days of construction will mitigate the construction noise impacts, and employing dust
control during construction will mitigate any adverse impacts to the air.
There is the potential for odor issues associated with operation of a collection system. During design, sewers and
pump stations will be evaluated for inclusion of odor control. If necessary, odor control mechanisms will be installed.
No public health issues associated with the construction of the Recommended Plan are anticipated, as a wastewater
collection system is constructed to solve the public health issue of contamination of groundwater by septic systems.
Any impacts associated with these alternatives will be mitigated during final design.
3.14.1.1.7 Violation of Federal, State, or Local Environmental and Land Use Statutes or
Regulations and Plans Imposed by Such Statues and Regulations
Implementation of the Recommended Plan will not violate any federal, state or local environmental and land use
statues/regulations, nor will it violate any plans imposed by these statutes/regulations. All local rules and regulations
will be addressed during the design phase and implemented fully during construction.
3.14.1.2 Indirect Impacts
3.14.1.2.1 Changes in Development and Land Use Patterns
The Recommended Plan contained herein has been sized for wastewater flows that were estimated from existing
developed lots and those designated as buildable in the future according to the current State Land Use Code
recorded at the Town Assessor Office and local zoning. In addition, early coordination with Nantucket Planning
identified areas of Town where the use of second dwelling are approved. Reviewing historic records of second
dwellings showed that approximately 12 percent of properties constructed second dwellings. This CWMP update took
Assessor records, GIS data and applied zoning to evaluate the individual parcels within the Needs Areas to first
make sure that the parcel met current zoning and then applied the zoning and land area to see if it met approval for a
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second dwelling. Utilizing these results, we then applied a factor of 25 percent, basically double of historic figure of
12 percent, to arrive at a conservative estimate for future development needing sewer service.
Early and extensive communication with Nantucket’s various land use departments have assisted in the proposed
Project contained herein. Coordinated communication will continue during the design and construction phases of the
proposed Project to ensure that any change brought as a result of the Project is welcomed and in the town’s best
interest.
While the introduction of sewer infrastructure in itself does not serve to promote or deny growth, the local regulatory
mechanisms and Zoning Board do. After the 2004 CWMP/FEIR was approved, the Town took extraordinary
measures to identify all Needs Areas where existing zoning posed issues and made changes. This revised zoning
was applied to the revisions done for calculating flows and loads in this CWMP Update and presented itself as a
positive move towards not only reducing the potential for sprawl and unwarranted growth, but preserving the limited
wastewater capacity in the existing infrastructure allowing for highest and best use. This serves to help maintain the
character of Nantucket while also serving to preserve and protect the valuable water resources that Nantucket is
known for. The intent of this CWMP is to solve the problems of the existing development and existing environmental
concerns, while concurrently serving to discourage unconstrained and unregulated development.
3.14.1.2.2 Pollution Stemming from Changes in Land Use
There will be no pollution stemming from changes in land use.
3.14.1.2.3 Damage to Sensitive Ecosystems
Sensitive Ecosystems include wetlands, priority habitats of rare species, estimated habitats of rare wildlife, and
vernal pools. There is a potential for temporary impacts to sensitive ecosystems during construction of collection
systems (sewer lines and pump stations), but these will be mitigated during design and construction. No permanent
or long term impacts are anticipated. The entire Town is overlain with the NHESP as is shown in Figure 3-11.
There are a variety of sensitive ecosystems on the Island, many noted through the NHESP. This Project will work to
avoid any impact to any surrounding areas to these resource areas. In evaluating potential impacts to any state-listed
species in the proposed Project area, there is no evidence of impact due to the sewers’ proposed locations in existing
right of ways and/or roadways (all pre-disturbed areas). There is no plan of any cross-country routes.- under the Final
recommended Plan contained herein. In areas where proposed infrastructure is in close proximity of protected
habitats, close attention will be paid to these locations to determine if the proposed infrastructure can be moved
further outside of the habitat areas or that they are placed so as to avoid or minimize potential impacts. The main
concern of NHESP with the Final Recommended Plan in 2004 was the proposed Madaket WWTF site. As was
discussed in a previous section, the Town worked under NHESP Permit to complete a botanical study, as well as
with the MHC to conduct an Intensive Survey on this site. There were multiple species identified in the NHESP
Report as rare and/or endangered-both plant and animal. The MHC Intensive Survey did not uncover any resources
on the 25-acre parcel evaluated. Communication was initiated early in the CWMP Update process with both agencies
in order to complete the mandated work as early in the process as could be done. With the results of both, the Town
determined that the cost, both financially and to the environment, could be extensive and opted to relook at
alternatives in order to eliminate utilizing this site to construct a WWTF and groundwater discharge bed. The
alternatives analysis confirmed that this site could be eliminated from the proposed planning by collecting,
transmitting, treating and discharging the Needs Areas from the western portion of the Island at Surfside WWTF
instead. Surfside WWTF is designed to treat 5.25 MGD with a Groundwater Discharge Permit of 3.4 MGD. The Final
Recommended Plan contained in this CWMP Update totals flows of 4.0 MGD so the Town is working to modify its
existing Groundwater Discharge Permit. The Town filed BRP WP 83 and BRP WP 11 to do just that. MassDEP has
confirmed an approval to modify the existing Groundwater Discharge Permit to meet the VWMP Update demand of
4.0 MGD. With this proposed Groundwater Discharge Permit modification, there is no damage to any sensitive
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ecosystem as the existing discharge beds are proposed to be used with loading at a slightly higher rate than is now
done and no new construction will be needed. . Refer to Appendix XX for correspondence.
Based on the on-going degradation and documented nutrient impairment through the MEP in multiple areas on Island
due to failing and/or improperly operating onsite wastewater disposal systems, it has been determined that optimizing
these onsite wastewater disposal systems are a larger and more detrimental threat to resources in this area. With the
proposed sewer plan, the water resources degradation from onsite systems will be eliminated thus affording the area
to rebound and the species now located within these areas to be protected from possible further degradation.
In addition, with the proposed directional drilling of sewer infrastructure, and/or infrastructure proposed in existing
right of ways and/or roadways that are pre-disturbed, impacts will be avoided.
3.14.1.2.4 Socioeconomic Pressures for Expansion
Connection of the Needs Areas to the Surfside WWTF should not affect socioeconomics as it will be a flow-based
system for those parcels included in the updated Needs Analysis and clearly identified in the planning process. There
will be some small amount of “in-building” expected with parcels that are designated as developable in the State land
Use Codes. While some “in-building” could lead to additional development in this area, it is negligible and would not
increase budget needs for school systems, roadway maintenance, fire protection, and other Town services.
The proposed collection system will be constructed in phases, with full build out not expected until well after the 20-
year planning period. With the methodology utilized to estimate future wastewater flows, using the current State Land
Use Codes, only those properties that currently exist and those categorized as developable now will be allotted flows.
If a property is coded as non-developable now with onsite wastewater system, it will remain undevelopable when
municipal sewer is brought to the area. This conforms to the State’s sustainability goals.
The proposed routes of the sewer infrastructure for the Needs Ares are conceptually designed in this CWMP Update
Report. Based on these elements, the following items are discussed:
3.14.1.2.4.1 Effect On Land Use
The Project Areas will not have a permanent negative impact on any land use. There will be temporary
impacts during construction that will be almost eliminated with the low pressure sewers due to directional
drilling methods and routes for proposed infrastructure within existing right of ways/roadways. The proposed
plan for Madaket and Warrens Landing is to directional drill all low pressure sewers with the capability to
keep one roadway lane open for traffic. All proposed properties in these two Needs Areas to be sewered are
primarily residential properties, with a few small businesses, so there will be no impact to any commercial
entities. IN addition, scheduling will be done so as to not interrupt the summer season where occupancy is
high. This is normal and customary on Island. Other areas will be utilizing existing right of ways and
roadways-pre-disturbed areas for proposed construction of pipes and collection system infrastructure. There
may be temporary impact to residences, but a public outreach plan will be in place for notices to be sent to
any areas during construction of any potential impacts.
3.14.1.2.4.2 Effects On Streams and/or Interbasin Transfers
There is no proposed effect on streams and no Interbasin Transfer.
3.14.1.2.4.3 Limitations For Future Expansion
The proposed project in the Recommended Plan will be limited to future expansion. The wastewater system
is designed as “flow-based” to meet the current Needs. This will also serve to meet Executive Order 385 as
“Sustainable” and limit any potential sprawl.
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3.14.1.2.4.4 Reliability, Operation and Maintenance
The proposed plan with utilizing the Surfside WWTF is already designed to be reliable with the appropriate
on-going operation and maintenance standards. The WWTF was designed and constructed to meet a plan
of 5.25 MGD. The proposed Recommended Plan contained herein is for 4.0 MGD, which is well under
design capacity. The Town has a completed O&M Manual for the facility. Refer to Appendix H for the O&M
manual.
3.14.1.2.4.5 Legal and/or Municipal Agreements And Permitting
All legal, municipal and permitting required as part of the systems implementation will be attained according
to the requirements of MassDEP. The has filed both BRP WP 11 and BRP WP 83 to revise its Groundwater
Discharge Permit at the Surfside WWTF to allow for 4.0 MGD discharge. A complete Hydrogeological
Evaluation was completed and filed. Preliminary meetings with MassDEP approved the Hydrogeological
Evaluation and ensuing results.
The Town adopted Sewer Districts after the completion of the 2 004 CWMP to be able to properly manage its
capacity at both the Surfside and Siasconset WWTFs. The Needs Areas included herein will follow the formal
process now in place of adding to the existing Sewer Districts. Town Meeting action is required, as well as a host of
qualifying criteria set forth by the Department of Public Works. This process has history to show that the adoption of
Sewer Districts affords the Town the degree of management needed to properly address any future need for
expansion and the detailing of the Needs Areas in this CWMP and associated flows meet the current conditions at
the facilities.
3.15 SUMMARY OF ENVIRONMENTAL IMPACT
The proposed Project contained herein details very little, if any, environmental impact. The major change from the
2004 CWMP is the elimination of the proposed Madaket WWTF and groundwater discharge beds. The Town
completed the May 14, 2004 MEPA Certificate requirements of an Intensive Survey under permit with MHC and a full
botanical survey under permit from NHESP at the Madaket site. Based on the results of this due diligence, the Town
opted to eliminate utilizing this site and thus has eliminated the major environmental concerns/impacts associated
with the former plan. The town will continue to communicate with the MHC and NHESP, as well as all local
jurisdictions as it moves forward during design and construction in order to identify and mitigate early on any potential
impacts that may arise with the proposed Project.
3.16 FLOW AND WASTE REDUCATION – MUNICIPAL WATER UPDATE
Nantucket understands the significance of minimizing its wastewater flows in order to maintain permit conditions at
the Surfside WWTF, as well as provide sufficient capacity for future Needs Areas. Nantucket’s potable water system
is managed and distributed through the Wannacomet Water Company, which is an enterprise division of the Town.
Nantucket has its own source of fresh drinking water created by the glacier 12,000-10,000 years ago. Water is drawn
from an aquifer that sits below the island with ground water that filters down through sand and clay. The clay
prevents sea water from invading the “lens.”
Potable water comes from three groundwater wells located throughout the mid-Island. The Milestone Well #2 and
State Forest Well #3 are protected by Zone I delineations with a radius of 400 feet surrounding the well. The
Milestone Well #1 has a Zone I protection that extends 250 feet from the perimeter of the well. The drinking water
comes from two different levels of the aquifer. The water system distributes water through a network of water mains
that range in size from two inches up to sixteen inches in diameter. The Town also has a 2,000,000-gallon water
storage tank located in North Pasture that was brought into service in 2010. In addition, in 2010, Wannacomet
brought public water to the Madaket area of Town, which was shown in the 2004 CWMP as entirely on private wells.
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While the entire Needs Area is not serviced with public water, it was brought from warren’s Landing to Massasoit
Village and then in 20111 to F Street, Tennessee Avenue to North Cambridge street ending on Little Neck Way. This
mainly accounts for the northern portion of the Needs Area leaving the middle and southern portions to rely on
private wells.
According to the Water Department, in 2012 the Town produced and delivered 612,314,000 gallons of drinking water
from all of its wells. Highest demand was on July 6, 2012, which is expected given the population surges during this
summer period. Nantucket relies entirely on rainfall to recharge its Sole Source Aquifer, with 2012 receiving 32
inches in rainfall, with average rainfall recharge around 43 inches per year.
The Wannacomet Water Company also provides public educational materials on a multitude of sources including
Consumer Drinking Water Quality Reports, which include: Annual Statistics as to use, Recharge Rates and new
developments; Conservation Opportunities, Opportunities for Public Participation, Leak Detection, Watershed
Protection/Resource Management, and various links to homeowner sites that provide information on billing, tips on
finding land fixing leaks and other Town information. The site also provides a water use calculator to estimate use
and plan for conserving use on a household level.
There are a host of conservation groups on Island dedicated to the preservation and protection of the precious water
resources. The Nantucket Land Council is one such example. Their website is also indicative of the type of public
outreach and education afforded to the Island. See Appendix K for examples of education materials.
In 1996 the Safe Drinking Water Act (SDWA) was amended to provide communities with more information about the
ways in which they can protect their drinking water sources from contamination. The amendments require states to
create a Source Water Assessment Program for all their public drinking water systems. Private wells typically serving
single households are not included in this requirement. According to the Environmental Protection Agency website:
“The purpose of the program is to provide local leaders, water suppliers, and citizens with the information necessary
to protect public drinking water sources from contamination. Through this program, state drinking water programs are
responsible for:
identifying the land areas which provide water to each public drinking water source in their state;
completing an inventory of existing and potential sources of contamination in those areas;
determining the susceptibility of each drinking water system to contamination; and
releasing the results of the assessment to water users and other interested entities. “
The Town has a completed Source Water Assessment and Protection (SWAP) Report (2004) that was compiled by
the MassDEP to inventory land uses within the wellhead protection zones. This Report details plans to avoid any
potential impact from land uses to the well zones. This can be found in Appendix K.
Figure 2-19 details the Town’s Public Water Supply System. All water materials are included in Appendix K.
Summary3.16.1
The Town operates and maintains a public water system that serves portions of the Island. Wannacomet Water
Company also offers to provide rates and services for private fire protection Island-wide. The Town has initiated and
maintains an aggressive water conservation program. The goals set by the Water Company are to promote the
efficient use of water through education and maintains an updated and comprehensive website for public education.
Refer to Appendix K for all water conservation information.
Wannacomet Mission Statement
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“The Wannacomet Water Company shall strive to provide high quality drinking water that exceeds all established
Federal and Commonwealth drinking water standards, provide the highest level of customer and water related
services achievable, educate and inform the public of the need to protect Nantucket’s water resources, and to
accomplish this mission using prudent utility practices and responsible fiscal management.”
3.17 I/I UPDATE
Since the 2004 CWMP, the Town has moved forward with a number of Infiltration/Inflow (I/I) projects that were
included in the 2004 Capital Improvements Plan. The Town Sewer District I/I Study was completed in 2006 and
identified a number of areas for rehabilitation projects to eliminate extraneous water getting into the sewer system.
The Town Sewer District was divided into a number of “Mini-Systems” - each with a specific target of rehabilitation.
The Town completed the Brant Point I/I Study in 2006 with a subsequent Brant Point Sewer Replacement Phase I
completed in 2007.
Phase IIA (Mini-System N-1) design and construction was completed in 2009, which was in the downtown area.
Phase IIB construction (Mini-System N-2) is currently on-going with rehabilitation and sewer replacement in portions
of downtown. This Project includes the removal of approximately 5,000 linear feet of existing vitrified clay pipe and
replacement with 8 to 10 inch PVC pipe; replacement of approximately 2,300 linear feet of sewer pipe with pipe
bursting and removal of approximately 3,000 linear feet of cast iron and AC water pipe and replace with 6 to 8 inch
cement lined ductile iron pipe. To date, Phase IIB has identified and corrected major I/I at Jetties beach, identified
and repaired major root blockage in Lyon Street and Fair Street, and replaced multiple manholes and damaged
sewer pipe throughout the Downtown area. Several sources of inflow from roof leaders and other sources have also
been identified and corrected during the course of construction. Operators at the Sea Street pump station recently
commented on the noticeable reduction in inflow observed at the pump station that is likely attributable to the Phase
IIB improvements. This Phase is projected to be completed with final full width paving in fall 2014.
The remaining mini-systems to be completed include the areas further from the water in the Pleasant Street, Vesper
Lane, Monomoy Road, Naushop Subdivision and outlying areas of the Town Sewer District. Our office is examining
CCTV inspection records to identify areas in need of repair, and analyzing available inflow data to pinpoint potential
sources of I/I. With this data, we are working to identify and prioritize the future Phases of construction work. Based
on preliminary investigation and conversation with DPW, we anticipate that the next phase will continue to focus on
sewer infrastructure repair in the N-1 Mini System. These previous phases were detailed in earlier reports from other
sources and need to be updated based on current conditions. Rather than including approximately $86,520,000
(2014 dollars recommended in 2006) for this future work without having full knowledge of current conditions, this
CWMP Update is recommending the Town conduct an I/I Study and Flow Metering Update to evaluate future needs.
A CY2015 project evaluation form (PEF) is being submitted to MassDEP for State Revolving Funds to cover the cost
of this study. The results of the I/I and Flow Metering study will be incorporated into the CIP at a future date.
3.18 GRREENHOUSE GAS
The EOEEA issued the Greenhouse Gas (GHG) Emissions Policy and Protocol in April 2007 in reference to the
phrase “damage to the environment’, which also included the emission of GHG. This was further amended by the
Massachusetts Environmental Policy Act Office (MEPA) in November 2008 to provide for the consideration of issuing
permits, licenses and other administrative approvals that appropriate authorities also consider “reasonably
foreseeable climate change impacts due to GHG emissions”. This policy now requires “that certain projects
undergoing review by the MEPA Office quantify the project’s GHG emissions and identify measures to avoid,
minimize, or mitigate such emissions.” The following summary details the potential for Nantucket to evaluate GHG
conceptually during the CWMP planning process with recommendations to review and incorporate sustainable
design standards during final design.
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With respect to the GHG emission policy, it is the intent of the Town and this Project to focus attention on those areas
where creative forethought, as well as potential new technology in looking at the long-term wastewater solutions, may
also benefit the environment in innovative and resourceful ways.
Greenhouse Gases can be quantified by both direct and indirect sources. The two primary sources included herein to
quantify GHGs are electricity (indirect) and natural gas use (direct). Electricity is used to power pumps, motors and
other equipment whereas natural gas is used solely for heating systems at the WWTF and pump stations.
An energy efficiency evaluation of the Surfside WWTF was completed by National Grid as a National Grid Scoping
Study Energy Evaluation. As part of the CWMP, Woodard & Curran performed an energy efficiency evaluation of the
Surfside WWTF to further refine the recommendations of a National Grid Scoping Study Energy Evaluation. The
evaluation was performed by JK Muir LLC and is described in a memo dated July 2, 2014, which is provided in the
appendices of the full report. Refer to Appendix H for the full Report.
A summary of the recommended cost saving measures is a follows:
Provide instrumentation and controls modifications to allow automatic blower on/off cycling which will
minimize energy usage for the primary sludge holding tanks.
Provide instrumentation and controls modifications to allow automatic cycle blower on/off cycling which will
minimize energy usage for the secondary waste activated sludge holding tanks.
Modify the piping for the draft pumps that convey flow from the anoxic tanks to the aeration tanks to allow a
reduction in the number of pumps that need to run under reduced flow conditions.
Install a new VFD on the odor control fan and make programming changes to allow for a range of operating
conditions to optimize ventilation while minimizing energy usage.
There is a potential opportunity to modify the control system programming set points for the membrane air
scour blowers to optimize their usage and reduce the blower run time which would reduce energy usage.
Sustainable Design Standards3.18.1
These sustainable design standards are set forth to provide for GHG reductions where possible by maximizing
energy efficiencies in many instances. The recommended plan includes low-pressure sewer, gravity sewer with one
and possibly two pump stations. There is no building, such as a WWTF that would be applicable to evaluate. The
Town will also evaluate equipment standards that can be reviewed at during the design process, such as:
Equipment/Process Design – The following standards are applicable to all new equipment installations and
equipment replacement and are to be evaluated/incorporated into preliminary and final design.
New motors greater than 1 horsepower (HP) for pumps, blowers, fans, mixers and other drives shall be1.
premium efficiency duty.
New motors greater than 10 HP for pumps, blowers, fans, mixers and other drives shall consider Variable2.
Frequency Drivers (VFDs) where variable speed operation can reduce energy consumption.
New equipment shall incorporate high efficiency models where cost-effective.3.
Pump sizes and combinations to maximize average efficiency shall be evaluated at preliminary/final design.4.
Incorporation of renewable energy including, but not limited to, solar PV systems and wind energy systems5.
shall be considered for inclusion into the design.
Sewer force mains shall be sized, designed, and routed in preliminary design to reduce the average6.
pumping power required to convey sewer flow.
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Future replacement and upgrade of existing equipment, whether under scheduled maintenance or not shall7.
incorporate the aforementioned standards.
SCADA System3.18.2
Supervisory Control and Data Acquisition (SCADA) is a centralized system which monitors and controls entire sites,
or complexes of systems spread out over large areas. Recommendations are included in this Report for SCADA
system enhancements as part of the Surfside WWTF upgrades and as a part of the implementation of the
Recommended plan. The SCADA system will consider installation, which will help to reduce GHG emissions as the
pump stations will be monitored on a remote basis versus having someone actually visit the station via a vehicle
every time an alarm occurs. The SCADA will save the use of gasoline fuel and oil in the vehicles and the reduction of
vehicular traffic will save the emissions from such on a regular basis.
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4.PHASE IV REPORT – FINAL RECOMMENDED PLAN
4.1 NEEDS AND STUDY AREAS FINAL RECOMMENDED PLAN
The 2004 CWMP identified areas of the Town that were not deemed long-term sustainable with on-site wastewater
disposal systems due to a number of criterion. One criterion that was not in existence at this time was the
Massachusetts Estuaries Program (MEP) Reports, which identified areas impacted with nutrient loading, specifically
nitrogen. Nitrogen loading from various sources including on-site wastewater systems, stormwater, fertilizer and
various other sources were the subject of the MEP in southeastern Massachusetts, Cape and Islands starting in
2003. When the 2004 CWMP Update was completed, none of the final results of the MEPs were completed so no
nitrogen loading criterion was added to the screening criteria utilized to determine the need for an off-site wastewater
solution. The Town received its 2004 CWMP/EIR MEPA Certificate with a caveat that once the MEP studies were
completed, the CWMP/EIR would need to be updated. This CWMP Update is satisfying this mandate.
The Needs Areas, in order of priority, are as shown in Table 4-1.
Table 4-1: Updated Needs Areas and Area of Concern
Needs Area MEP Area
Somerset
Priority Route to Surfside for
Madaket/Warrens Landing-MEP
Madaket Madaket Harbor/Long Pond
Warren’s Landing Madaket Harbor/Long Pond
Monomoy Nantucket Harbor/Polpis Harbor
Shimmo Nantucket Harbor/Polpis Harbor
Hummock Pond North Hummock Pond
Hummock Pond South Hummock Pond
PLUS Parcels - Infill in Town Sewer
District
Multiple - Nantucket Harbor/Polpis
Harbor/Hummock Pond
Somerset Needs Area – Priority Number One4.1.1
The Somerset Needs Area was evaluated in the 2004 CWMP and rated within the acceptable range to be
determined to be an area needing an off-site wastewater solution based on the existing criteria at that time. The area
qualifies as a Need based on the 2004 CWMP data.
The Somerset Needs Area immediately abuts the Town sewer District to the southwest. The geographic area is a
predominantly residential area, with small, dense lot sizes.
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The Needs Area encompasses approximately 196 acres, of which 181 are developed. There are 243 total parcels,
with 209 developed. There are 31 undeveloped residential parcels, with 30 potentially developable. There are 18
municipal/conservation parcels within this Needs Area. With few available developable parcels, sewering this Needs
Area does not promote any unwanted sprawl. The Needs Area is plagued with severe soils, over 84 percent
Evesboro Sands that are detailed by the United States Department of Agriculture Soils
Conservation Service as constrained as they perc very fast and do not afford time in the soil layers to cleanse before
discharging into groundwater and thus travel fast to the Pond. The other predominant soil associations in this Needs
Area are Riverhead and Berryland Variant soils with qualities posing severity for on-site wastewater systems of
permeability, depth to seasonal high groundwater and susceptibility to flooding. Evesboro Sands do not adequately
filter the effluent, which leads to groundwater contamination
There are approximately 7 acres out of the total 151 acres of severe groundwater limitation, which limits the proper
absorption of effluent and leads to potential groundwater contamination. The area is serviced by municipal water.
Over 67 percent of the area’s systems’ are located on lots less than or equal to ½ acres and approximately 7 percent
were built before 1978 (Creation of Title 5).
4.1.1.1 Final Recommended Plan
Based on qualifying criteria from the 2004 CWMP, Somerset Needs Area continues to qualify as an area needing an
off-site wastewater disposal solution in this 2013 CWMP Update. This Needs Area is a priority due to its location to
Surfside WWTF and the necessary infrastructure route for Madaket/Warrens Landing must traverse through this
area. Somerset is Phase I of the Final Recommended Plan.
The Final Recommended Plan is to collect, transport and treat this Needs Area at the Surfside WWTF.
Madaket and Warrens Landing Needs Areas4.1.2
The Madaket Needs Area was evaluated in the 2004 CWMP and rated within the acceptable range to be determined
to be an area needing an off-site wastewater solution based on the existing criteria at that time. The 2004 CWMP did
not have the advantage of years’ worth of water quality testing that is showing significant and rising degradation to
Madaket Harbor, Hither Creek, Long Pond and other water resources in this geographical area since then. A major
change is the completed and approved Madaket Harbor/Long Pond MEP Report and subsequent Draft TMDL noting
the degradation in this area due to nitrogen loading from on-site wastewater disposal systems. The Madaket Harbor
MEP adds significant weight to the existing 2004 criteria to maintain this as a “Needs Area” and needing an off-site
wastewater solution. New zoning since 2004 in this area has further reduced potential for unwarranted growth due to
introduction of sewer infrastructure
The Madaket Harbor-Long Pond Embayment System as depicted in the MEP Report is a complex estuary with full
tidal basins (Madaket Harbor, Hither Creek) connected via Madaket Ditch to the brackish waters of Long Pond that is
influenced greatly by wetlands. Madaket Harbor is approximately 746 acres, semicircular in shape, open to
Nantucket Sound on its western edge, and open to the Atlantic on its southwest corner via a cut between Smith’s
Point and Tuckernuck. The Harbor is relatively a shallow water body, 4-5 feet deep, with a deeper channel (6-9ft.)
running east and north to the coastline of the Sound. There are a few deeper channels that pre date Hurricane Esther
(1961), but much of the harbor has filled in as a result of the opening that was created by this storm. This condition
existed until Hurricane Gloria (1985), which enabled a closure of the gap to Smith’s Point. via drifting sand bars.
Because the southwest edge is open, circulation is high (flushing every 3 days), and water quality is good. Epiphytic,
and macro algae are limited in presence and density, and eel grass beds are healthy. Madaket Harbor and Long
Pond make up a unique ecosystem encompassing approximately 9 square miles. These two systems are
hydrologically connected via Hither Creek and the Madaket Ditch. Long Pond is somewhat isolated from the whole
Town of Nantucket (#225139.00)4-3 Woodard & Curran
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system, and has been evaluated as having separate water quality issues. It is relatively narrow and winding with
depths of 4-6 feet with no deep basins.
Water quality results from 2010 to present show Hither Creek, Long Pond and North Head of Long Pond as not
meeting water quality standards. Madaket Harbor, which is an open marine basin, is not degraded as the other water
resources in the area are due to its high flushing component. The Clean Water Act and TMDL processes that
followed the MEP Report mandate that the Town develop and implement solutions for restoration of these water
resources. The MEP included the development of a target nitrogen load to determine the amount of total nitrogen
mass loading reduction required for system restoration. This included reducing the nitrogen load from the landfill,
which is an on-going process. In addition, a reduction of septic loading, 100 percent in the Hither Creek Watershed,
resulted in a 72 percent reduction in the entire Watershed.
The overall plan to meet the water quality standards is to continue with the landfill mining where water quality testing
is showing potential improvement. The 2012 Annual Water Quality results stated that Long Pond showed significantly
lower total nitrogen levels, 40 percent, in 2012 versus results shown in 2010. This trend is being further evaluated in
the 2013 Annual Water Quality Program to determine whether it is as a direct result of the landfill mining and can be
credited as such. In addition, the service area as defined in Figure 1-1 is proposed to be sewered, which is what the
2004 CWMP showed. The main difference in this Needs Area between 2004 and current is that the area included is
defined up to and not crossing over Millie’s Bridge.
The Needs Area encompasses approximately 342 acres, of which 222 are developed. There are 572 total parcels,
with 381 developed. Out of the total 572 parcels, 120 are municipal and/or conservation parcels and 71 are
undeveloped with only 17 of these potentially developable. With few available developable parcels, sewering this
Needs Area does not promote any unwanted sprawl. The Needs Area is plagued with severe soils, over 96 percent
comprised of Riverhead Sandy Loam, Berryland and Medisaprists that are detailed by the United States Department
of Agriculture Soils Conservation Service as constrained as they perc very fast and do not afford time in the soil
layers to cleanse before discharging into groundwater and thus travel fast to the water resources in the area. Also
over 30 percent of severe groundwater limitation plague this Needs Area Properties of this soil association are
permeability, depth to seasonal high groundwater and susceptibility to flooding. Riverhead Sandy Loams do not
adequately filter the effluent, which leads to groundwater contamination. The other predominant soil associations in
this Needs Area is Riverhead Sandy Loam, which is a moderately rapid permeable soil and does not provide
sufficient filtering of effluent, and Pawtucket Mucky Peats and Berryland, which are both plagued as very wet soils
and not conducive to septic tank absorption fields.
There are approximately 110 acres out of the total 342 acres of severe groundwater limitation, which limits the proper
absorption of effluent and leads to potential groundwater contamination. The majority of this Needs Area is serviced
with private water, thus posing additional threat from inadequately operating on-site wastewater disposal systems.
Over 53 percent of the area’s systems’ are located on lots less than or equal to ½ acres and over 55 percent were
built before 1978 (Creation of Title 5).
4.1.2.1 Final Recommended Plan
Based on qualifying criteria from the 2004 CWMP, together with the results of nitrogen loading documented in the
Madaket Harbor/Long Pond MEP, Madaket Needs Area qualifies as an area needing an off-site wastewater disposal
solution in this CWMP Update. This Needs Area is Phase 2 of the Final recommended Plan. While the criteria within
this geographic area rates it as the top priority due to environmental and public health issues, it requires Somerset to
be designed and constructed first in order to carry the wastewater to Surfside.
The Final Recommended Plan is to collect, transport and treat this Needs Area at the Surfside WWTF.
Town of Nantucket (#225139.00)4-4 Woodard & Curran
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Warrens Landing Needs Area4.1.3
The Warrens Landing Needs Area was evaluated in the 2004 CWMP and rated within the acceptable range to be
determined to be an area needing an off-site wastewater solution based on the existing criteria at that time. The 2004
CWMP did not have the advantage of years’ worth of water quality testing that is showing significant and rising
degradation to Madaket Harbor, Hither Creek, Long Pond and other water resources in this geographical area since
then. A major change is the completed and approved Madaket Harbor/Long Pond MEP Report and subsequent Draft
TMDL noting the degradation in this area due to nitrogen loading from on-site wastewater disposal systems. The
Madaket Harbor MEP adds significant weight to the existing 2004 criteria to maintain this as a “Needs Area” and
needing an off-site wastewater solution.
The Madaket Harbor-Long Pond Embayment System as depicted in the MEP Report, is a complex estuary with full
tidal basins (Madaket Harbor, Hither Creek) connected via Madaket Ditch to the brackish waters of Long Pond that is
influenced greatly by wetlands.
Warren’s Landing is part of the overall Madaket Watershed. According to the Town’s 1990 Water Resources Plan
Report, the groundwater in Warren’s Landing flows directly towards Long Pond and Madaket Ditch, which are both
impacted with nutrient degradation per the MEP Report.
The Warren’s Landing Needs Area is north of the Madaket Needs Area just east of Long Pond and north of Madaket
Ditch in the Madaket Harbor Watershed. Madaket Harbor is approximately 746 acres, semicircular in shape, open to
Nantucket Sound on its western edge, and open to the Atlantic on its southwest corner via a cut between Smith’s
Point and Tuckernuck. The Harbor is relatively a shallow water body, 4-5 feet deep, with a deeper channel (6-9ft.)
running east and north to the coastline of the Sound. There are a few deeper channels that pre date Hurricane Esther
(1961), but much of the harbor has filled in as a result of the opening that was created by this storm. This condition
existed until Hurricane Gloria (1985), which enabled a closure of the gap to Smith’s Point. via drifting sand bars.
Because the southwest edge is open, circulation is high (flushing every 3 days), and water quality is good. Epiphytic,
and macro algae are limited in presence and density, and eel grass beds are healthy. Madaket Harbor and Long
Pond make up a unique ecosystem encompassing approximately 9 square miles. These two systems are
hydrologically connected via Hither Creek and the Madaket Ditch. Long Pond is somewhat isolated from the whole
system, and has been evaluated as having separate water quality issues. It is relatively narrow and winding with
depths of 4-6 feet with no deep basins.
Water quality results from 2010 to present show Hither Creek, Long Pond and North Head of Long Pond as not
meeting water quality standards. Madaket Harbor, which is an open marine basin, is not degraded as the other water
resources in the area are due to its high flushing component. The Clean Water Act and TMDL processes that
followed the MEP Report mandate that the Town develop and implement solutions for restoration of these water
resources. The MEP included the development of a target nitrogen load to determine the amount of total nitrogen
mass loading reduction required for system restoration. This included reducing the nitrogen load from the landfill,
which is an on-going process. In addition, a reduction of septic loading, 100 percent in the Hither Creek Watershed,
resulted in a 72 percent reduction in the entire Watershed.
The overall plan to meet the water quality standards is to continue with the landfill mining where water quality testing
is showing potential improvement. The 2012 Annual Water Quality results stated that Long Pond showed significantly
lower total nitrogen levels, 40 percent, in 2012 versus results shown in 2010. This trend is being further evaluated in
the 2013 Annual Water Quality Program to determine whether it is as a direct result of the landfill mining and can be
credited as such. In addition, the service area as defined in Figure 1-1 is proposed to be sewered, which is what the
2004 CWMP showed. The main difference in this Needs Area between 2004 and current is that the area included is
defined up to and not crossing over Millie’s Bridge.
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Data from 2004 details this Needs Area encompasses approximately 49 acres, of which 26 are developed. There are
99 total parcels, with 68 developed. There are 19 undeveloped parcels of which 8 are developable. With few
available developable parcels, sewering this Needs Area does not promote any unwanted sprawl. New zoning since
2004 in this area has further reduced potential for unwarranted growth due to introduction of sewer infrastructure.
The Needs Area is plagued with severe soils, approximately 100 percent Evesboro Sands that are detailed by the
United States Department of Agriculture Soils Conservation Service as constrained as they perc very fast and do not
afford time in the soil layers to cleanse before discharging into groundwater and thus travel fast to the Pond.
Properties of this soil association are permeability, depth to seasonal high groundwater and susceptibility to flooding.
Evesboro Sands do not adequately filter the effluent, which leads to groundwater contamination.
There are approximately 10 acres out of the total 49 acres of severe groundwater limitation, which limits the proper
absorption of effluent and leads to potential groundwater contamination. Over 91 percent of the area’s systems’ are
located on lots less than or equal to ½ acre. Less than one percent of properties were built before 1978. The small lot
sizes and existing developed parcels contribute to density of systems with approximately 68 systems greater than 2
per acre.
4.1.3.1 Final Recommended Plan
Based on qualifying criteria from the 2004 CWMP, together with the results of nitrogen loading documented in the
Madaket Harbor/Long Pond MEP, Warren’s Landing Needs Area qualifies as an area needing an off-site wastewater
disposal solution in this CWMP Update. This Needs Area is Phase 2, as part of the Madaket Needs Area, of the Final
recommended Plan. While the criteria within this geographic area rates it as the top priority due to environmental and
public health issues, it requires Somerset to be designed and constructed first in order to carry the wastewater to
Surfside.
The Final Recommended Plan is to collect, transport and treat this Needs Area at the Surfside WWTF.
Monomoy Needs Area4.1.4
The Monomoy Needs Area was evaluated in the 2004 CWMP and rated within the acceptable range to be
determined to be an area needing an off-site wastewater solution based on the existing criteria at that time. The 2004
CWMP did not have the advantage of years’ worth of water quality testing that is showing significant and rising
degradation to the Nantucket and Polpis Harbors since then. Monomoy Needs Area is fully within the Nantucket
Harbor Watershed and included in the Town’s Annual Water Quality Testing with records of testing/sampling results
from 2005 to present. This is one significant change since the 2004 CWMP, as water quality testing and results were
not available at that time. Since 2004, the Nantucket Harbor MEP Report has been completed and two TMDLs have
been issued by MassDEP, one in Nantucket Harbor and another in Polpis Harbor.
The Monomoy Needs Area immediately abuts Nantucket Harbor in the Town Basin. The Town Sewer District has
been extended into the Needs Area as delineated in 2004, thus new boundaries for this CWMP Update were drawn.
The upper portion of the 2004 area was cut off at Gardner Road and this is where the Shimmo Needs Area now
begins. The Monomoy and Shimmo Needs Areas differ slightly from the 2004 Report’s maps. The new delineations
were based on recommendations from Town officials, marine and costal resources, Natural Resources and Board of
Health that have historically worked on the Project. The new delineations more accurately capture Monomoy with
smaller, denser lots than Shimmo, which has larger lot sizes. These two Needs Areas have been the subjects of
model run scenarios completed for the Town by SMAST in order to arrive at solutions to meet the TMDLs in the
overall watershed. Refer to the previous section for additional information on the model runs scenarios completed as
part of the MEP.
The Needs Area encompasses approximately 391 acres, of which 303 are developed. There are 272 total parcels,
with 219 developed. There are 35 undeveloped parcels of which 25 are residentially developable in the future. There
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are also 13 municipal/conservation parcels within this Needs Area. With few available developable parcels, sewering
this Needs Area does not promote any unwanted sprawl. The Needs Area is plagued with severe soils, over 90
percent Evesboro Sands that are detailed by the United States Department of Agriculture Soils Conservation Service
as constrained as they perc very fast and do not afford time in the soil layers to cleanse before discharging into
groundwater and thus travel fast to the Pond. Properties of this soil association are permeability, depth to seasonal
high groundwater and susceptibility to flooding. Evesboro Sands do not adequately filter the effluent, which leads to
groundwater contamination. The other predominant soil association in this Needs Area is Riverhead Sandy Loam,
which is a moderately rapid permeable soil and does not provide sufficient filtering of effluent.
There are approximately 44 acres out of the total 391 acres of severe groundwater limitation, which limits the proper
absorption of effluent and leads to potential groundwater contamination. The majority of this Needs Area is serviced
with private water, thus posing additional threat from inadequately operating on-site wastewater disposal systems.
Approximately 9 percent of the area’s systems’ are located on lots less than or equal to ½ acres and over 35 percent
were built before 1978 (Creation of Title 5).
4.1.4.1 Final Recommended Plan
Based on qualifying criteria from the 2004 CWMP, together with the results of nitrogen loading documented in the
Nantucket Harbor MEP, Monomoy Needs Area qualifies as an area needing an off-site wastewater disposal solution
in this 2013 CWMP Update. The criteria within this geographic area rate it as the fourth priority due to environmental
and public health issues documented in the 2004 CWMP, CWMP Update and MEP Report. Sewering this geographic
area is vital to meeting the thresholds established and documented in the MEP and subsequent TMDL.
The Final Recommended Plan is to collect, transport and treat this Needs Area at the Surfside WWTF
Shimmo Needs Area4.1.5
The Shimmo Needs Area was evaluated in the 2004 CWMP and rated within the acceptable range to be determined
to be an area needing an off-site wastewater solution based on the existing criteria at that time. The 2004 CWMP did
not have the advantage of years’ worth of water quality testing that is showing significant and rising degradation to
the Nantucket and Polpis Harbors since then. Monomoy Needs Area is fully within the Nantucket Harbor Watershed
and included in the Town’s Annual Water Quality Testing with records of testing/sampling results from 2005 to
present. This is one significant change since the 2004 CWMP, as water quality testing and results were not available
at that time. Since 2004, the Nantucket Harbor MEP Report has been completed and two TMDLs have been issued
by MassDEP, one in Nantucket Harbor and another in Polpis Harbor.
The Shimmo Needs Area immediately abuts Nantucket Harbor north of Monomoy and south of Polpis Harbor. The
lower portion of the 2004 area was amended to start at Gardner Road and this is where the Shimmo Needs Area
now begins. The Monomoy and Shimmo Needs Areas differ slightly from the 2004 Report’s maps. The new
delineations were based on recommendations from Town officials, marine and costal resources, Natural Resources
and Board of Health that have historically worked on the Project. The new delineations more accurately capture
Monomoy with smaller, denser lots than Shimmo, which has larger lot sizes. These two Needs Areas have been the
subjects of model run scenarios completed for the Town by SMAST in order to arrive at solutions to meet the TMDLs
in the overall watershed. Refer to the previous section for additional information on the model runs scenarios
completed as part of the MEP.
The Needs Area encompasses approximately 702 acres, of which 327 are developed. There are 203 total parcels,
with 106 developed. There are 27 undeveloped parcels of which 14 are potentially developable. There are over 70
municipal/conservation parcels within this Needs Area. With few available developable parcels, sewering this Needs
Area does not promote any unwanted sprawl. The Needs Area is plagued with severe soils, over 84 percent
Evesboro Sands/Plymouth-Evesboro series that are detailed by the United States Department of Agriculture Soils
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Conservation Service as constrained as they perc very fast and do not afford time in the soil layers to cleanse before
discharging into groundwater and thus travel fast to the Pond. Properties of this soil association are permeability,
depth to seasonal high groundwater and susceptibility to flooding. Evesboro Sands do not adequately filter the
effluent, which leads to groundwater contamination. The other predominant soil association in this Needs Area is
Pawtucket Muck and Berryland, which are very wet, mucky soils and not conducive to soil absorption fields.
There are approximately 175 acres out of the total 702 acres of severe groundwater limitation, which limits the proper
absorption of effluent and leads to potential groundwater contamination. The majority of this Needs Area is serviced
with private water, thus posing additional threat from inadequately operating on-site wastewater disposal systems.
Approximately 3 percent of the area’s systems’ are located on lots less than or equal to ½ acres and 17 percent were
built before 1978 (Creation of Title 5).
4.1.5.1 Final Recommended Plan
Based on qualifying criteria from the 2004 CWMP, together with the results of nitrogen loading documented in the
Nantucket Harbor MEP, Shimmo Needs Area qualifies as an area needing an off-site wastewater disposal solution in
this CWMP Update.
The criteria within this geographic area rate it as the fifth priority due to environmental and public health issues
documented in the 2004 CWMP, CWMP Update and MEP Report. Sewering this geographic area may be required in
order to meet the thresholds established and documented in the MEP and subsequent TMDL. As part of the Adaptive
Management Plan included herein, this geographic area will be evaluated for sewering in conjunction with the
restructuring of the jetties, fertilizer management, sewering of both the Town Sewer District unconnected parcels and
PLUS parcels. The need and timing to design and construct this Needs area will be based on results of the
aforementioned efforts to meet the TMDLs established in both Nantucket and Polpis Harbors.
The Final Recommended Plan is to collect, transport and treat this Needs Area at the Surfside WWTF
Hummock Pond North Study Area4.1.6
The Hummock Pond North Needs Area was not evaluated separately in the 2004 CWMP - this is a new addition to
the CWMP Update based on the Hummock Pond MEP, which was started in spring of 2013 with and completed in
early 2014 with results now in draft form. The 2004 CWMP did not have the advantage of years’ worth of water
quality testing that is showing significant and rising degradation to the Pond since then, specifically Head of
Hummock. Hummock Pond was part of the original 89 embayments planned for study in the MEP, but was eliminated
during the program due to budgetary constraints. With years of results in the Town’s Annual Water Quality Testing
Program showing severe degradation, the Town pursued the MEP with supplemental funds raised locally in order to
get the study completed. The Town received the Draft Report in January 2014, showing results of 81 percent
degradation due to wastewater.
Since 2004, the Town has extended the Town Sewer District into portions of this Needs Area, which touches the
northern limits of the Hummock Pond Watershed as delineated and approved by the Town. Refer to Figure 4- for a
map of this Needs Area.
The Hummock Pond North Needs Area immediately abuts the Head of Hummock Pond, which is severely degraded
as detailed in the Hummock Pond MEP. Head of Hummock is detailed as supporting severely degraded habitat and
the focus of groundwater discharge to this portion of the Watershed and well beyond the threshold N level as
established for this Watershed.
The Needs Area encompasses approximately 962 acres, of which 426 are developed. There are 374 total parcels,
with 205 developed. There are 81 undeveloped parcels with 66 having potential for future development. There are
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over 44 municipal/conservation parcels located within this needs Area. With few available developable parcels,
sewering this Needs Area does not promote any unwanted sprawl. The Needs Area is plagued with severe soils,
over 76 percent Evesboro Sands that are detailed by the United States Department of Agriculture Soils Conservation
Service as constrained as they perc very fast and do not afford time in the soil layers to cleanse before discharging
into groundwater and thus travel fast to the Pond. Properties of this soil association are permeability, depth to
seasonal high groundwater and susceptibility to flooding. Evesboro Sands do not adequately filter the effluent, which
leads to groundwater contamination. The other predominant soil association in this Needs Area is Berryland and
Medisaprists, which are moderately rapid permeable, poorly drained soils and does not provide sufficient filtering of
effluent and have high water tables.
There are approximately 103 acres out of the total 962 acres of severe groundwater limitation, which limits the proper
absorption of effluent and leads to potential groundwater contamination. Over 39 percent of the area’s systems’ are
located on lots less than or equal to ½ acres and over 25 percent were built before 1978 (Creation of Title 5).
4.1.6.1 Final Recommended Plan
Based on current qualifying criteria, Hummock Pond North Needs Area qualifies as an area needing an off-site
wastewater disposal solution in this CWMP Update. The criteria within this geographic area rate it as the sixth priority
due to environmental and public health issues documented in the 2004 CWMP, CWMP Update and MEP Report.
Sewering this geographic area may be required in order to meet the thresholds established and documented in the
MEP and any subsequent TMDL that MassDEP may issue as a result of threshold limits established. As part of the
Adaptive Management Plan included herein, this geographic area will be evaluated for sewering in conjunction with
the bi-annual breaches to the Pond and any efforts undertaken to remove the Head of Hummock from the main
Pond. The need and timing to design and construct this Needs area will be based on results of the aforementioned
efforts to meet the threshold limit established in Hummock Pond.
The Final Recommended Plan is to collect, transport and treat this Needs Area at the Surfside WWTF
Hummock Pond South Needs Area4.1.7
The Hummock Pond South Needs Area was evaluated in the 2004 CWMP (was the Cisco Needs Area in 2004) and
did not rate within the acceptable range to be determined to be an area needing an off-site wastewater solution
based on the existing criteria at that time. The 2004 CWMP did not have the advantage of years’ worth of water
quality testing that is showing significant and rising degradation to Hummock Pond since then. The Hummock Pond
South Needs Area immediately abuts the Hummock Pond’s eastern shoreline, which shows a gradient of degradation
based on the Pond areas. The upper level of the Pond abutting the Head of Hummock is severely degraded, the
middle portion is moderately degraded, while the lower levels of the Pond that immediately abut the shoreline show
degrading conditions, but not as significant as other portions of the Pond.
The Needs Area encompasses approximately 721 acres, of which 328 are developed. There are 358 total parcels,
with 282 developed. There are 41 undeveloped parcels with 21 having the potential for future development. There
are over 14 parcels either municipal, conservation or agricultural. With few available developable parcels, sewering
this Needs Area does not promote any unwanted sprawl. The Needs Area is plagued with severe soils, over 80
percent Evesboro Sands that are detailed by the United States Department of Agriculture Soils Conservation Service
as constrained as they perc very fast and do not afford time in the soil layers to cleanse before discharging into
groundwater and thus travel fast to the Pond. Properties of this soil association are permeability, depth to seasonal
high groundwater and susceptibility to flooding. Evesboro Sands do not adequately filter the effluent, which leads to
groundwater contamination. The other predominant soil associations in this Needs Area are Riverhead-Nantucket
Complex, which is a moderately extremely slow permeable soil and Berryland, which does not provide sufficient
filtering of effluent.
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There are approximately 56 acres out of the total 721 acres of severe groundwater limitation, which limits the proper
absorption of effluent and leads to potential groundwater contamination. The majority of this Needs Area is serviced
with private water, thus posing additional threat from inadequately operating on-site wastewater disposal systems.
Over 24 percent of the area’s systems’ are located on lots less than or equal to ½ acres and over 32 percent were
built before 1978 (Creation of Title 5).
4.1.7.1 Final Recommended Plan
Based on current qualifying criteria, Hummock Pond South Needs Area qualifies as an area needing an off-site
wastewater disposal solution in this CWMP Update. The criteria within this geographic area rate it as the seventh
priority due to environmental and public health issues documented in the 2004 CWMP, CWMP Update and MEP
Report. Sewering this geographic area may be required in order to meet the thresholds established and documented
in the MEP and any subsequent TMDL that MassDEP may issue as a result of threshold limits established. As part of
the Adaptive Management Plan included herein, this geographic area will be evaluated for sewering in conjunction
with the bi-annual breaches to the Pond and any efforts undertaken to remove the Head of Hummock from the main
Pond. The need and timing to design and construct this Needs area will be based on results of the aforementioned
efforts to meet the threshold limit established in Hummock Pond.
The Final Recommended Plan is to collect, transport and treat this Needs Area at the Surfside WWTF
Miacomet Needs Area4.1.8
The Miacomet Needs Area was evaluated in the 2004 CWMP and did not rate within the acceptable range to be
determined to be an area needing an off-site wastewater solution based on the existing criteria at that time. The 2004
CWMP did not have the advantage of years’ worth of water quality testing that is showing significant and rising
degradation to the Pond since then. While Miacomet Pond is not part of the Massachusetts Estuaries Program (MEP)
Studies as it is a freshwater body, the Pond does have a delineated watershed from the 1990 Water Resources
Protection Plan detailing the contributing areas to the watershed. Miacomet is included it in the Town’s Annual Water
Quality Testing with records of testing/sampling results from 2005 to present. This is one significant change since the
2004 CWMP, as water quality testing and results were not available at that time. In addition, the Pond has been
subject to severe flooding issues during storm events and the area generally is plagued with severe soil and
groundwater conditions. As of this Report writing, the Town is undertaking a major plan to evaluate Miacomet Pond
and the flooding and degradation issues that it is experiencing.
Also since 2004, the Town has extended the Town Sewer District into portions of the 2004 Miacomet Pond Study
Area, with this 2013 Area delineation being the remaining areas from 2004 that have not been sewered. This updated
delineation includes the major land area immediately abutting the Pond.
The Miacomet Needs Area immediately abuts Miacomet Pond to the west. According to the Town’s Annual Water
Quality Testing records from 2005 to present, Miacomet Pond is a closed coastal salt pond that is seldom (once in
the past ten years) opened to the ocean to flush out nutrients and organic matter on the ebb tide and receive saline
waters on the flood tide. The present non-tidal state and watershed nutrient inputs has resulted in a decline in
nutrient related water quality throughout the pond, with poor water quality conditions the present norm. All of the
water quality results show a consistency with a nutrient impaired basin. However, if the freshening of this basin
continues, it may come into a new equilibrium as a purely freshwater system and will need to be reassessed as such.
However, it will be difficult for Miacomet Pond to maintain itself as a purely freshwater system as storm overwash and
rising sea level will tend to periodically cause seawater intrusion into its lower basin.
In reviewing the water quality results from 2010 to present, the nutrient impairment from nitrogen and phosphorus
appear to be severe in the upper portions of the Pond (Station 3), middle portions of the Pond (Station 1) and fair in
the lower reaches (Station 2) abutting the ocean. As is discussed above, this is not a water resource that can be
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opened to the open ocean for flushing due to its freshwater state, so solutions need to be arrived at looking at land
uses in the watershed-mainly wastewater, fertilizer and stormwater.
The Needs Area encompasses approximately 295 acres, of which 181 are developed. There are 124 total parcels,
with 102 developed. With few available developable parcels, sewering this Needs Area does not promote any
unwanted sprawl. The Needs Area is plagued with severe soils, over 84 percent Evesboro Sands that are detailed by
the United States Department of Agriculture Soils Conservation Service as constrained as they perc very fast and do
not afford time in the soil layers to cleanse before discharging into groundwater and thus travel fast to the Pond.
Properties of this soil association are permeability, depth to seasonal high groundwater and susceptibility to flooding.
Evesboro Sands do not adequately filter the effluent, which leads to groundwater contamination. The other
predominant soil association in this Needs Area is Riverhead Sandy Loam, which is a moderately rapid permeable
soil and does not provide sufficient filtering of effluent.
There are approximately 40 acres out of the total 295 acres of severe groundwater limitation, which limits the proper
absorption of effluent and leads to potential groundwater contamination. The majority of this Needs Area is serviced
with private water, thus posing additional threat from inadequately operating on-site wastewater disposal systems.
Over 25 percent of the area’s systems’ are located on lots less than or equal to ½ acres and over 28 percent were
built before 1978 (Creation of Title 5).
4.1.8.1 Final Recommended Plan
Based on current qualifying criteria, Miacomet Needs Area qualifies as an area needing an off-site wastewater
disposal solution in this CWMP Update. The criteria within this geographic area rate it as the eighth priority due to
environmental and public health issues documented in the 2004 CWMP, CWMP Update and the Town’s
comprehensive water quality data. The timing to design and construct this Needs area will be based on results of the
current and future water quality studies in conjunction with annual water quality testing in the Pond.
The Final Recommended Plan is to collect, transport and treat this Needs Area at the Surfside WWTF
PLUS Needs Area and Town Sewer District In-Fill4.1.9
The PLUS parcels are various areas either within or directly abutting the Town Sewer District that for one reason or
another were left out of the Sewer District in error. Most are sandwiched within the existing sewer or are either at the
beginning or end of sewered streets. A complete review with the Town’s Planning Director and Director of Public
Works identified and approved these parcels to be included in the sewering plan moving forward. Most either
immediately abut infrastructure or are in close proximity of collection system components.
Town Sewer District parcels that remain unconnected to the sewer are a priority for connection in to the system as
they impact the water resources as documented in the MEP. The Town is currently working to mandate, through the
Board of Health Local Regulation 69.00, all parcels abutting existing sewer infrastructure connect within a specific
time frame. There are additional unconnected parcels where no infrastructure exists that will be part of a future
endeavor to design and connect.
The following Table 4-2 details the sewering priorities as established in the previous sections.
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4.1.9.1 Sewering Priorities
Based on the existing supporting data, this CWMP Update recommends the following sewering priorities:
Needs Area Priority Reasoning
Somerset This Needs Area needs to be completed first due to the
proposed route of bringing the highest Needs Areas priorities-
Madaket and Warrens Landing- to Surfside WWTF.
Hummock Pond North and South Needs Areas are also
proposed to flow through Somerset to the Surfside WWTF.
Madaket and Warren’s Landing Needs Areas Established TMDL, Large number of documented Title 5
Technical failures (inability to meet groundwater separation)
contributing to nitrogen load through groundwater resources
and MEP Model detailing removal of on-site wastewater
meeting TMDL. Current ACO Program area with Board of
Health.
Monomoy Established TMDL and MEP Model detailing removal of on-
site wastewater meeting TMDL.
Shimmo Established TMDL and MEP Model detailing removal of on-
site wastewater meeting TMDL. Priority based on Adaptive
Management Plan and need for N reductions in Harbor.
Hummock Pond North Pending TMDL and MEP Model detailing removal of on-site
wastewater meeting TMDL. May make sense to sewer earlier
in process as Madaket and Warrens Landing will traverse
through the area towards Somerset on way to Surfside
WWTF.
Hummock Pond South Pending TMDL and MEP Model detailing removal of on-site
wastewater meeting TMDL. This Needs Area to be prioritized
based on Adaptive Management Planning with breach and
removal of Head of Hummock from main body of Pond.
Miacomet Annual Water Quality Testing results depicting degradation
due to nutrient load from on-site systems.
Town Sewer District Infill and PLUS Parcels These areas can be serviced at any time as infrastructure
exists within close proximity. It is recommended that
these parcels be mandated to connect under Local
Regulation 69.00 in order to reduce nitrogen loading in
Nantucket Harbor Watershed.
Table 4-3 details the remaining Study Areas Final recommended Plan.
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Table 4-2: Study Areas Final Recommended Plan
The 2004 Study Areas that have been re-evaluated based on the results of the MEP Reports include:
2004 Study Area MEP Area
Polpis Nantucket Harbor/Polpis Harbor
Pocomo Nantucket Harbor/Polpis Harbor
Wauwinet Nantucket Harbor/Polpis Harbor
Quidnet Sesachacha Pond
These 2004 Study Areas were re-evaluated in this CWMP Update and while not considered as areas needing an off-
site wastewater solution in 2004 or 2013, they abut Nantucket Harbor in various locations and contribute in various
manners to the Nitrogen loading documented in the MEP Report. Based on additional studies completed by SMAST
on scenarios in the Harbors to reduce nitrogen loading to meet established TMDLS, sewering these areas did not
serve to contribute to the reduction effort. It has been determined that a more cost effective approach to the Nitrogen
reduction be had through other contributors-fertilizer, stormwater and future build out. These efforts will supplement
the structured solutions being planned such as sewering, raising the jetties to afford a deeper tidal exchange and
dredging. This CWMP Update is making recommendations to limit additional, future nitrogen loading with current and
build-out conditions within the Adaptive Management Plan contained herein.
These Study Areas are recommended for oversight under the Town’s Septage Management Plan. As part of the
overall Adaptive Management Plan include herein, this Report is also recommends consideration for future
management utilizing Innovative / Alternative systems due to each area’s geographic locations within Nitrogen-
sensitive embayments as detailed in the MEP Reports. I/A systems will afford a higher nutrient reduction, up to 50
percent of TN, than a conventional Title 5 system is able to do. Each Study Area is delineated in this CWMP Update
on Figure 2-20.
4.1.9.2 Adaptive Management Plan to meet MEP and TMDLs
The Final Recommended Plan included at the beginning of this Chapter is a result of comprehensive analysis of the
not only the sites themselves, but all criteria associated with the physical environment. This includes those areas that
were the subject of study under the Massachusetts Estuaries Program (MEP) and have subsequently been issued
Total Maximum Daily Loads (TMDLs) or have water quality thresholds established. As a result, these areas are being
required to address the water quality issues identified in the MEP Reports and meet established water quality
thresholds. Here we present an Adaptive Management Plan to address all MEP Areas with a plan defined as a
structured, iterative process with adaptation as necessary to achieve mandated goals. The major goal is to reduce
nutrient loading over time starting with projects that are easily implemented and monitor results through the Town’s
Annual Water Quality Program. This will enable the Town to make educated decisions on adding
In this case, the Town is structuring implementation of projects that were included in further study by SMAST with
extensive modeling done to affirm results as a result of implementation in specific estuary areas. For example, the
Town looked at multiple solutions to meet the TMDLs established in Nantucket Harbor and Polpis Harbor. These
included fertilizer reduction as per the Town’s Fertilizer By-law, coupled with reducing nutrient load from on-site
wastewater systems, dredging of the entrance to Polpis Harbor and raising the east and west jetties to a height that
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will afford a stronger and deeper flush of fresh ocean water into the Harbor. Adaptive Management purports to look at
which of these solutions are easily implemented giving the Town the “biggest bag for its buck” and monitoring what
results are achieved and then adapting measures as needed to adjust results. For example, the jetties project is
underway with the Army Corps of Engineers due to safety concerns. Once the construction is completed, which is
scheduled for late winter 2014/early spring 2015, water quality testing will determine the extent of flushing that will
then come through the entrance to Nantucket Harbor and how far up into the Harbor the flush is realized. How does
this relate to the nutrient concentrations in the Harbor at the testing stations over time? The modeling done for this
geographic area told us that we need to do other tasks in coordination with the jetties in order to meet established
thresholds-what would the next task be that is easily implemented given the options available? This is the first step in
the Adaptive Management Plan. The next logical step is to look at the parcels that currently abut sewer infrastructure
in the Town sewer District and mandate under Local Regulation 69.00 they connect into the municipal sewer system.
These parcels are still relying on the on-site wastewater disposal systems, which are documented as contributing
nutrients into the Harbor. Eliminating these on-site systems reduces nutrient loading into the Harbor and thus
contributes towards meeting the thresholds in the TMDL.
Future decisions can be made such as to implement additional tasks that will meet the established resource
management objectives and, either passively or actively, accrues information needed to improve future management
options. Information learned will help the Town to add or reduce solutions as needed to meet established thresholds.
Adaptive Management in the MEP areas will serve to not only help the Town change conditions within the estuaries,
but will help it continue to learn about the overall system. This learning will ultimately help the Town in its long-term
management of all these diverse systems on Island.
The following identifies the specific Adaptive Management Plan (ADM) approach for each embayment area included
in the MEPs.
4.1.9.3 Sesachacha Pond
CWMP UPDATE FINAL ADAPTIVE MANAGEMENT PLAN TO MEET SESACHACHA POND THRESHOLD
ESTABLISHED IN MEP (NO Formal TMDL, BUT THRESHOLD LEVELS ESTABLISHED AND DOCUMENTED)
The Town will continue to breach Sesachacha Pond twice annually in April and October. Sesachacha Pond Sentinel
Station will be included in the Town’s Annual Water Quality Testing program to continue to monitor results. The
Town’s 2013 Annual Water Quality Monitoring Program will support previous results in order to petition the state to
remove Sesachacha Pond from the State’s List of Impaired Waters.. At the time of this Report, the final Sesachacha
Pond Report had not been received from SMAST.
4.1.9.4 Madaket Harbor/Long Pond
CWMP UPDATE FINAL ADAPTIVE MANAGEMENT PLAN TO MEET MADAKET HARBOR / LONG POND
THRESHOLD ESTABLISHED IN MEP (Draft TMDL issued)
The Town will continue to mine the landfill and monitor water quality testing done in this location for further reductions
of N. Madaket and Warren’s Landing Needs Areas are proposed for municipal sewering at the Surfside WWTF thus
removing 100 percent of the land use wastewater contributing to the degradation, which based on the MEP , will
serve to meet the Draft TMDL issued for this area.
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4.1.9.5 Nantucket Harbor/Polpis Harbor
CWMP UPDATE FINAL ADAPTIVE MANAGEMENT PLAN TO MEET NANTUCKET HARBOR / POLPIS HARBOR
TMDL
The Town will continue with its mandate to sewer all areas located within the Town Sewer District where
infrastructure exists under Local Regulation 69.00. The reconstruction of the east and west jetties in Nantucket
Harbor are currently under design with the ACOE and as of last update in July 2014, due to be bid in late fall 2014
with construction starting early 2015. The Town has begun enforcement of its Fertilizer Regulations, which will be an
on-going effort Island-wide, with particular attention paid to the Harbor Watershed areas. As the above approaches
are implemented, data will support the need for additional work, which includes extending the municipal sewer to the
Monomoy Needs Area. Future considerations include extending sewer to Shimmo Needs Area, implementing a Local
Regulation for I/A systems within the Study Areas delineated within MEP Areas and potential future stormwater
BMPS based on the Town completing a Stormwater Master Plan.
The Town will continue to monitor water quality in Nantucket and Polpis Harbor through its Annual water Quality
testing Program. The historical MEP Sentinel Stations will be sampled on a regular basis in order to monitor results
as the Town moves forward with its plan to meet the TMDLs established in this location.
4.1.9.6 Hummock Pond
CWMP UPDATE FINAL ADAPTIVE MANAGEMENT PLAN TO MEET HUMMOCK POND THRESHOLD
ESTABLISHED IN MEP (No Formal, issued TMDL to date. The following recommendation is based on the
results detailed in the Report, which will form the future basis for a TMDL)
The Town has identified Hummock Pond South and Hummock Pond North as Needs Areas requiring an off-site
wastewater solution. The Adaptive Management Plan contained herein proposes to collect, transport and treat these
Needs Areas at the existing Surfside WWTF, thus removing the 81 percent wastewater from land use in the
Watershed. In addition, the Town will work towards more finite planning for semi-annual breaches of Hummock Pond
by forecasting weather conditions looking towards conditions that present the appropriate weather conditions, tides
and northerly winds to afford an opening that stays open to tidal flushing for a minimum of four days. Hummock Pond
Sentinel Station 3 will be included in the Town’s Annual Water Quality Testing program to continue to monitor results.
Another piece to this Plan is the separating of the Head of Hummock from the main Pond as was detailed earlier in
this Report. This Plan is currently being evaluated through the Nantucket Land Council together with the Town.
4.2 SURFSIDE WASTEWATER TREATMENT FACILITY RECOMMENDED IMPROVEMENTS
The following are the improvements Woodard & Curran is recommending for the Surfside Wastewater Treatment
Facility (WWTF). We prepared estimated conceptual level project capital costs for these improvements and the
recommended schedule for these improvements is included in the capital improvement plan section of this report. We
have organized the recommended improvements into the following categories:
Improvements for future capacity needs
Improvements for reliability
Improvements for energy efficiency
4.3 IMPROVEMENTS FOR FUTURE CAPACITY
As part of our contract with the Town for Madaket Wastewater Planning, Woodard & Curran performed a capacity
evaluation of the Surfside WWTF to determine the feasibility of accepting the projected flows and loads from the
Madaket and Warren’s Landing Needs Areas. The evaluation included an assessment of existing and projected
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wastewater flows and loads, an assessment of current WWTF performance, and a determination of required
improvements. A detailed description of our capacity analysis is provided in Appendix ##.
The findings of our capacity assessment were as follows:
The future condition is a maximum daily flow of 4.0 million gallons per day (MGD) which includes build out of
the existing sewer areas and sewer extension to the needs areas.
The Surfside WWTF has sufficient capacity to receive wastewater at the future condition provided that minor
changes are made to operational practices and additional aeration blower capacity is provided.
Although the Surfside WWTF has capacity, the future maximum daily flow of 4.0 MGD exceeds the Town’s
MassDEP Groundwater Discharge Permit limit of 3.5 MGD for daily flow to the groundwater discharge beds.
Therefore, expansion of the groundwater discharge capacity or revisions to the groundwater discharge
permit are required. See section below for more detailed information relative to the beds.
Expansion of groundwater discharge capacity or revisions to the Groundwater Discharge Permit would be
required at the future condition even if Madaket and Warren’s Landing wastewater was not treated at the
Surfside WWTF.
The recommended improvements to the Surfside WWTF for future capacity include additional aeration blowers and
modifications to the nitrate recycle system as follows:
Additional Aeration Blowers4.3.1
The Surfside WWTF existing aeration system includes three Aerzen positive displacement blowers, each with a
design capacity of 950 standard cubic feet per minute. Based on our calculations for oxygen requirements, we
determined that the existing aeration tank blowers do not have enough capacity for the future condition, therefore two
additional blowers are needed (one to provide the additional capacity required and one to serve as a redundant
backup). With this additional blower capacity, there is sufficient capacity for the flow and loads at the future condition.
Modifications to the Nitrate Recycle4.3.2
During our evaluation, WWTF operations staff expressed concerns with having the ability to denitrify at the future
condition because of the anoxic tank volume and because nitrate recycle from the membrane tanks may have a high
dissolved oxygen (DO) concentration, which could inhibit denitrification. Our calculations (as well as the original GE
Zenon design calculations) and the plant data that we have been provided indicate that these two items would not be
a problem. However, there are many variables that can affect the actual results. Therefore, to address this concern,
we recommend gathering additional nitrate data and monitoring the results as flows and loads to the Surfside WWTF
increase in the future. We also have prepared a conceptual layout and conceptual cost estimate for improvements to
the nitrate recycle system in case future problems are encountered. The improvements include modifying the existing
recycle from the membrane tanks with redirection to the aeration tanks and an additional, separate, nitrate recycle
from end of the aeration tanks to the anoxic tanks.
4.4 IMPROVEMENTS FOR RELIABILITY
We have identified and recommend several improvements to increase the reliability and long-term effectiveness of
operation of the Surfside WWTF. Some of the improvements for reliability were identified and evaluated as part of our
contract with the Town for the Alternatives Analysis, Recommendations and Conceptual Opinion of Probable Cost of
Proposed Upgrades to the Surfside WWTF and some the improvements were identified through the Surfside WWTF
capacity assessment.
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Corrosion Control4.4.1
The Surfside WWTF has experienced severe corrosion of the concrete and metal components at the headworks, and
there was concern that corrosion may have been occurring at other locations such as the primary clarifiers. The
corrosion is due to the presence of hydrogen sulfide, which is formed upstream in the collection system, particularly
in the force mains.
To address this concern, Woodard & Curran engaged a specialty sub-consultant, Bowker & Associates (Bowker), to
perform a sampling program, assess the corrosion, identify alternatives for addressing the situation, and provide a
recommended solution with opinion of probable construction cost. The Bowker study found severe hydrogen sulfide
corrosion at the headworks of the Surfside Wastewater Treatment Facility and recommended an oxygen injection
system, installed at the Sea Street Pump Station, for mitigation.
Woodard & Curran reviewed the Bowker Report and agrees with these findings and recommendations. The
recommended oxygen injection system has a higher capital cost than the other alternatives, however it has the
lowest life-cycle cost because it does not require the purchase of chemicals which are quite costly. A detailed
description of the Bowker corrosion control study is provided in the appendices of the full report that is included in
Appendix H.
Influent Screening4.4.2
An influent grinder was installed at the Surfside WWTF during the 2009 upgrade, however due to severe hydrogen
sulfide corrosion; the grinder is no longer functional and was removed. To evaluate this issue, a screening analysis
was conducted and documented in a memorandum entitled “Enhancements to the Surfside Wastewater Treatment
Facility” by AECOM, dated January 9, 2012. The memorandum outlined the importance of MBR system
pretreatment, identified pretreatment alternatives, and ultimately recommended the installation of a grinder in the
headworks to breakdown influent debris. A copy of this memorandum is included in Appendix H.
The Town was interested in receiving a second opinion regarding the need for membrane pretreatment (screen
versus grinder) and contracted Woodard & Curran to provide an Influent Screening Alternatives Assessment. A
detailed description of our influent screening alternatives analysis is provided in the full report, which included the
following tasks:
Review existing documentation related to influent screening including design plans, operation and
maintenance manuals, plant hydraulics, and the AECOM Memorandum dated January 9, 2012.
Identify feasible screening alternatives and/or combinations of alternatives suitable for a membrane
bioreactor treatment facility with primary clarifiers with the Surfside WWTF specific hydraulic and spatial
requirements and operational needs.
Provide a recommendation of the most desirable screening alternative with consideration given to process,
cost, operation and maintenance concerns.
Provide an opinion of probable cost for the recommended alternative including design, construction,
engineering and contingency suitable for securing funding.
After analysis of multiple alternatives, we recommend the installation of a new headworks consisting of two 6-mm
screens, two 2-mm band screens, and two wash presses for screenings handling. We also recommend that a new
vortex grit removal system is incorporated into the new headworks to address issues with existing corrosion and grit
equipment at the existing aerated grit chamber. We also recommend that this equipment is housed within a cedar
shingled building.
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Vactor Truck Unloading4.4.3
Currently, the vactor truck discharges directly into the primary settling tanks (PST). This means of discharging is not
ideal because the contents are not screened and bypass the grit removal processes, likely disrupting settling in the
PSTs. Woodard & Curran analyzed installing a vactor unloading station at the Surfside WWTF. Multiple locations and
options were considered for the vactor discharge station, including the recommendations described in the previous
memorandum entitled “Enhancements to the Surfside Wastewater Treatment Facility” by AECOM, dated January 9,
2012.
Based on our evaluation we recommend the installation of a concrete ramp adjacent to the proposed new
headworks. Catch basins would be installed at the bottom of the ramp. The vactor truck would back to the edge of
the concrete ramp and discharge its contents at the bottom of the ramp. The catch basins would allow for the liquid to
discharge through to the headworks and simultaneously prevent debris and objects from passing through. The
screened contents would then be removed with a loader truck and discharged into a dump truck, which would be
hauled to a disposal site.
Aeration Tank Instrumentation4.4.4
Surfside operations staff reported that the dissolved oxygen control instrumentation is not reliable and cannot be
utilized for aeration tank blower control as was the original design intent. Replacement of these instruments with
more reliable DO and oxidation reduction potential (ORP) measurement capability would enhance the ability to
operate the WWTF at the future condition.
Primary Sludge Pump Replacement4.4.5
There are three existing primary sludge pumps that were installed during the 1992 upgrades. Given the age of these
pumps, we anticipate that these pumps will need to be replaced within the 20-year planning period of this Report.
Membrane Removal Equipment4.4.6
Periodic removal and inspection of the membrane cassettes is recommended by the membrane manufacturer
(General Electric/Zenon). The Surfside WWTF does not currently have the equipment needed to remove the
membrane cassettes. When inspections have been done in the past, the Town is forced to rent a crane, which is a
costly option. We recommend installation of 6-ton rated travelling monorail crane and hoist to better facilitate regular
inspection of the membranes. This equipment would also allow operations staff to make minor repairs to the
membranes as needed.
Membrane Inspection and Replacement4.4.7
The ability to predict the expected life of membranes is very limited because membrane treatment for municipal
wastewater is a relatively new application. In addition, the characteristics of the influent wastewater, the treatment
process conditions, and the associated membrane fouling constituents can vary greatly among WWTFs. It is our
general understanding that the expected membrane life will be less than the 20-year planning period of this Report.
Based on correspondence with General Electric (GE)/Zenon, we understand that, as part of the terms of the original
membrane purchase, the Town has an agreement with GE/Zenon that membranes purchased before the 10-year
anniversary (approximately December of 2018) of the membrane installation may be purchased at a discount. The
discounted replacement price is established using a base price adjusted for inflation using the Consumer Price Index.
According to GE/Zenon, for 2013, the discounted replacement price for all four (4) trains would be $1,240,000 versus
the market price of $1,940,000 (costs do not include installation, freight or taxes). Given the significant cost savings
associated with purchasing the membranes prior to the 10-year anniversary, we recommend that the Town budget
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for the capital expense of replacement of half of the membranes and that a membrane inspection is made prior to
determining whether or not to make the purchase.
Supervisory Control and Data Acquisition (SCADA) System4.4.8
Through our evaluations we have identified several improvements to the Surfside WWTF SCADA system that would
enhance current operations. These recommended improvements are as follows:
Upgrade the IFIX software: the SCADA system depends on IFIX Software for its functionality. The version
of IFIX currently installed is outdated and does not work with newer versions of Microsoft Windows. If the
one of the existing computers were to fail and had to be replaced, it would come with a newer version of
Windows that would not be compatible with the IFIX software.
Provide remote access: installation of a hardware package that provides for secure remote access into the
SCADA system will allow WWTF operations staff to monitor and control the system as if they were sitting in
front of the SCADA PC at the Surfside WWTF which will save personnel time including prevention of
unnecessary trips to the facilities for off-hour nuisance alarms
Improve integration between the GE/Zenon system control panel and the SCADA master node: The
functionality of the GE/Zenon control panel should be fully accessible from the existing SCADA system. This
recommendation would accomplish the functionality.
Provide automatic report software: we recommend that reporting software (XLReporter) is included for the
SCADA system. This package can be configured to generate automatic reports of process variables and
alarms. Manual lab data can also be entered into the program to compare to readings received from online
instruments. The software can generate reports on any specified period (daily, weekly, monthly, etc.) and
can be formatted to be identical to regulatory agency reports to reduce the amount of staff time required for
reporting.
Provide operator training: development of a SCADA training plan for operations staff to take better
advantage of the SCADA system already in use at the wastewater sites within the Town.
4.5 IMPROVEMENTS FOR ENERGY EFFICIENCY
As part of the CWMP, Woodard & Curran performed an energy efficiency evaluation of the Surfside WWTF to further
refine the recommendations of a National Grid Scoping Study Energy Evaluation. The evaluation was performed by
JK Muir LLC and is described in a memo dated July 2, 2014, which is provided in the appendices of the full report.
Refer to Appendix H for the full Report.
A summary of the recommended cost saving measures is a follows:
Provide instrumentation and controls modifications to allow automatic blower on/off cycling which will
minimize energy usage for the primary sludge holding tanks.
Provide instrumentation and controls modifications to allow automatic cycle blower on/off cycling which will
minimize energy usage for the secondary waste activated sludge holding tanks.
Modify the piping for the draft pumps that convey flow from the anoxic tanks to the aeration tanks to allow a
reduction in the number of pumps that need to run under reduced flow conditions.
Install a new VFD on the odor control fan and make programming changes to allow for a range of operating
conditions to optimize ventilation while minimizing energy usage.
There is a potential opportunity to modify the control system programming set points for the membrane air
scour blowers to optimize their usage and reduce the blower run time, which would reduce energy usage.
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4.6 ESTIMATED CONCEPTUAL COST FOR IMPROVEMENTS
Woodard & Curran’s conceptual cost estimates for the Surfside WWTF improvements are summarized in the
following Table 4-4.
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Table 4-3: Surfside WWTF Final Recommended Improvements Cost Estimates
Construction
Design Engineering,
Permitting and Construction
Administration Subtotal
Contingency
(30%)Project Total
Improvements for Future Capacity
Blower Addition $388,000 $85,400 $473,000 $142,000 $615,000
Nitrified Recycle $371,000 $81,600 $453,000 $136,000 $589,000
Subtotal $1,204,000
Improvements for Reliability
Corrosion Control $361,000 $79,400 $440,000 $132,000 $572,000
Influent Screening and Vactor Truck Unloading $3,080,000 $677,000 $3,757,000 $1,127,000 $4,884,000
Aeration Tank Instrumentation $180,000 $40,000 $220,000 $66,000 $286,000
Primary Sludge Pump Replacement $176,000 $38,700 $215,000 $65,000 $280,000
Membrane Removal Equipment $116,000 $27,800 $144,000 $43,000 $187,000
Membrane Inspection and Replacement $806,000 $50,000 $856,000 $257,000 $1,113,000
SCADA Improvements $51,800 $60,800 $113,000 $34,000 $147,000
Subtotal $7,469,000
Improvements for Energy Efficiency
Sludge Blower Cycling $5,000 $5,000 $10,000 $3,000 $13,000
Secondary Sludge Blower Cycling $-$5,000 $5,000 $2,000 $7,000
Draft Pump Piping Modifications $7,500 $1,900 $9,000 $3,000 $12,000
Odor Control Fan VFD Implementation $25,500 $5,000 $31,000 $9,000 $40,000
MBR System Optimization $-$62,500 $63,000 $19,000 $82,000
Subtotal $154,000
Total $8,827,000
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The conceptual estimates are based on the following:
Equipment and materials costs were based on a combination of manufacturer budgetary quotations and
cost date we obtained from similar projects
Prevailing wage rates for labor
Project is tax exempt
Engineering and permitting services are included as allocations based on a percentage of the estimated
construction cost
A contingency of 30-percent is applied to the project cost
The conceptual cost estimates are indexed to the Engineering News Record (ENR) construction cost index
of 9681 for February 2014.
Modified Groundwater Discharge Permit - Additional Bed Loading4.6.1
The additional loading to the existing beds at the Surfside WWTF, from 3.4 MGD to 4.0 MGD, based on summer
loading at 4.0 MGD for the entire month of August only and at 2.92 MGD (summer average daily flow) for the
remainder of the year is feasible under current conditions and has been verbally approved by MassDEP after filing
both a modification to the existing Groundwater Discharge Permit -BRP-11 and the Hydrogeological Evaluation filing
-BRP-83. The transient models detail the most dramatic mound during the month of August, which is expected given
the maximum loading rate of 4.0 MGD for the entire month. While the modeling shows that additional loading raises
the mounds in the upper beds, the overall system is able to handle the additional flow with vertical separation in the
four foot range in bed #12, which previous records detail with the highest groundwater elevation. The remainder of
the year under the transient models clearly shows considerably less mounding with vertical separations exceeding
four feet. Additionally, the upgrades at the WWTF, most notably the upgrade to MBR technology, afford a highly
treated effluent discharge that travels to the open Atlantic Ocean with no environmental impacts.
The full flow to 4.0 MGD will not be seen immediately, but, rather over a 20-year planning period. It is also in the
Town’s CWMP Update as an alternative, to maintain communication with MassDEP and various Cape and
southeastern Massachusetts towns in the use of an ocean outfall. In a best case scenario at some point in the future,
the treated effluent from Surfside could be discharged through an outfall to the Atlantic Ocean.
The Groundwater Discharge Permit modification to 4.0 MGD affords the Town the highest and best use of the
existing Surfside WWTF.
4.6.1.1 Downstream Evaluation
In order to accommodate additional wastewater flows from the needs areas, select sections of sewer and wastewater
pump stations will require capacity upgrades.
The pipes that will require upgrade include the following:
Mizzenmast Road from Bartlett Road to Pine Valley Pump Station
Bartlett Road from Appleton Road to Surfside Road
Surfside Road from Bartlett Road to Surfside Pump Station
Surfside Road from South Shore Road to Surfside Pump Station
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Cost estimates for the upgrading the sewer pipe above were calculated similarly to the sewer for the needs areas at
$720 per linear foot.
The pump stations that will require upgrades to accommodate the additional wastewater flows from the needs areas
include:
Pine Valley Pump Station located on Mizzenmast Road
Surfside Road Pump Station
Based on the capacity of the pump stations as evaluated during the pump station assessment task, the schedule for
which the upgrades would be implemented may be determined at a future date based on when each needs area is
connected and the rate at which households are connected to the new system or based on availability of project
funding.
Cost estimates for upgrading the pump stations were calculated based on average pumping capacity similar to the
sewer needs areas.
These cost estimates are included in the Recommended Plan CIP, Figure 4-1.
4.6.1.2 Pump Station Evaluation
The proposed pump station assessment task will observe and document the condition of 10 of Nantucket’s 11
wastewater pumping stations. This task excludes the Sea Street Pump Station, which is currently being evaluated
separately. This review will observe the operational and physical condition of the stations various systems including,
but not limited to, the following:
Pump age, condition, pumping capacity/efficiency
Physical structures of the wet well, dry well or valve vault, control building and/or panel enclosures, hatches,
and ladders
Control equipment and systems - Control panels including age and physical condition of components and
enclosures
Mechanical equipment and systems - Miscellaneous mechanical systems such as unit heater, dehumidifier,
sump pumps.
Power systems and equipment - Power systems and equipment including generators, if they are on site.
These cost estimates are included in the Recommended Plan CIP, Figure 4-1.
4.6.1.3 Stormwater Recommendations
Implementation of structural and heightened non-structural controls are not recommended at this time. These
activities will require substantial capital costs, including purchase of multiple high efficiency regenerative air-vacuum
sweeping trucks, construction of structural controls to treat nitrogen at outfalls that drain portions of the downtown
area, as well as continued annual expenditures on ongoing implementation of sweeping and catch basin cleaning,
and maintenance of the structural controls. Preliminary estimates show both capital and ongoing operational costs
associated with these practices are very high per kg of nitrogen removed, as compared to management of fertilizer,
septic systems, and sewering. Based on discussions with Town Staff about implementation of these potential non-
structural and structural control practices to reduce nitrogen loading to the harbors from impervious cover, Woodard
& Curran has recommended the Town implement the following activities to reduce nitrogen loading from impervious
cover runoff:
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Continue its current street sweeping and catch basin cleaning operations in the downtown area;
Develop local bylaw and regulations to manage stormwater runoff during construction and post-construction
for new development and redevelopment;
Implement “adaptive management” for street sweeping, catch basin cleaning, and structural BMPs as
needed based on water quality results in Nantucket and Polpis Harbors; and
Develop a comprehensive island-wide Stormwater Management Master Plan. This Plan should build off of related
work completed to date including the drainage system map and the evaluation of drainage outfalls in the downtown
area to develop Plan that integrates existing and future stormwater capital planning, drainage operations and
maintenance efforts, regulatory requirements, public outreach and involvement, previously completed watershed and
water quality work, and known local problems such as areas prone to flooding. This Master Plan will help the Town to
holistically understand its stormwater assets, water quality and quantity issues, budgetary costs and drivers for these
costs, and develop a sustainable plan for long-term management of stormwater throughout Town. Ultimately, a
Master Plan can set the framework for a stormwater financing mechanism. This Plan is necessary to protect public
and environmental health, address water quality issues, and protect public and private drinking water supplies.
Although the Town is not regulated under EPA’s Phase II Small Municipal Separate Storm Sewer System (MS4)
stormwater program, the Town does have a need to manage its stormwater runoff to prohibit discharges from
causing or contributing to exceedances of water quality standards.
In addition, the Town has aging stormwater and sewer infrastructure, therefore has a high potential for illicit
connections or illicit discharges to the drainage system from improper connections or failing sewer pipes. The Plan
will also preserve recreational areas used for swimming and boating, commercial fisheries, and protect endangered
species habitat. The Town’s existing stormwater system was detailed in the July 2006 Sewer System Evaluation
Study. This Report recommended a series of improvements that would eliminate surge charging, street flooding, and
undersized piping and deteriorated structural integrity of the pipes. The plan was delineated into three phases, with
Phase I completed as of the writing of this Report. The 2004 CWMP carried approximately $24,000,000 worth of
stormwater improvements in the three phases consisting of both outfall and infrastructure improvements, with
approximately $5,000,000 completed to date. This Update Report is recommending a Stormwater Master Plan be
completed in order to fully assess previous recommendations, as well as assess any new tasks to be completed
based on current conditions. The previous budget is not carried on the Capital Improvements Plan as the
recommendation is to complete the Stormwater Master Plan in order to develop current conditions and needs. A
CY2015 project evaluation form (PEF) was submitted to MassDEP for State Revolving Funds to cover the cost of this
study. The results of this study will be incorporated into the CIP at a future date.
4.6.1.4 I/I Recommendations
Since the 2004 CWMP, the Town has moved forward with a number of Infiltration/Inflow (I/I) projects that were
included in the 2004 Capital Improvements Plan. The Town Sewer District I/I Study was completed in 2006 and
identified a number of areas for rehabilitation projects to eliminate extraneous water getting into the sewer system.
The Town Sewer District was divided into a number of “Mini-Systems” - each with a specific target of rehabilitation.
The Town completed the Brant Point I/I Study in 2006 with a subsequent Brant Point Sewer Replacement Phase I
completed in 2007.
Phase IIA (Mini-System N-1) design and construction was completed in 2009, which was in the downtown area.
Phase IIB construction (Mini-System N-2) is currently on-going with rehabilitation and sewer replacement in portions
of downtown. This Project includes the removal of approximately 5,000 linear feet of existing vitrified clay pipe and
replacement with 8 to 10 inch PVC pipe; replacement of approximately 2,300 linear feet of sewer pipe with pipe
bursting and removal of approximately 3,000 linear feet of cast iron and AC water pipe and replace with 6 to 8 inch
cement lined ductile iron pipe. To date, Phase IIB has identified and corrected major I/I at Jetties beach, identified
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and repaired major root blockage in Lyon Street and Fair Street, and replaced multiple manholes and damaged
sewer pipe throughout the Downtown area. Several sources of inflow from roof leaders and other sources have also
been identified and corrected during the course of construction. Operators at the Sea Street pump station recently
commented on the noticeable reduction in inflow observed at the pump station that is likely attributable to the Phase
IIB improvements. This Phase is projected to be completed with final full width paving in fall 2014.
The remaining mini-systems to be completed include the areas further from the water in the Pleasant Street, Vesper
Lane, Monomoy Road, Naushop Subdivision and outlying areas of the Town Sewer District. Our office is examining
CCTV inspection records to identify areas in need of repair, and analyzing available inflow data to pinpoint potential
sources of I/I. With this data, we are working to identify and prioritize the future Phases of construction work. Based
on preliminary investigation and conversation with DPW, we anticipate that the next phase will continue to focus on
sewer infrastructure repair in the N-1 Mini System. These previous phases were detailed in earlier reports from other
sources and need to be updated based on current conditions. Rather than including approximately $86,520,000
(2014 dollars recommended in 2006) for this future work without having full knowledge of current conditions, this
CWMP Update is recommending the Town conduct an I/I Study and Flow Metering Update to evaluate future needs.
A CY2015 project evaluation form (PEF) was submitted to MassDEP for State Revolving Funds to cover the cost of
this study. The results of the I/I and Flow Metering study will be incorporated into the CIP at a future date.
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Figure 4-1: Capital Improvement Plan - spreadsheet 11 X17
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4.7 AWARENESS OF AND ADAPTATION TO CLIMATE CHANGE – PLANNING FOR THE FUTURE
The potential impacts of climate change pose significant challenges and risks to communities, particularly shoreline
communities like Nantucket. Nantucket has already felt some of these impacts over the last few years with major
storms, particularly 2012 Hurricane Sandy that left serious erosion issues on multiple areas of the island. One
example is on the eastern shoreline where Baxter Road suffered significant impacts with buildings lost to the ocean
due to the seriously eroding shoreline. It is in this area that Town officials are now having to come up with a plan to
relocate municipal infrastructure in the existing roadway in order to avoid a catastrophe should future storms reach
water and sewer pipes. This area has shown that climate changes pose a real threat to the water resources. Up to
this point, while there has been erosion issues in various areas, the scientific community is just beginning its outreach
with real facts and figures and the overall concept of global warming / climate change has not been perceived as real
in the general public. The issue is now taking a front page due to the devastation experienced by the eastern shore of
the United States that started with Sandy in 2012.
Nantucket is in a position to plan for the future and take climate change into account when proposing new
infrastructure, as well as in its Capital Improvement and Management Planning preserving and protecting existing
infrastructure. As was noted in a recent NEWEA Position Paper by the New England Water Environment Association
on Climate Change and Water Resources, “The nation’s existing drinking water, stormwater, flood management, and
wastewater infrastructure is already in need of significant investments to maintain current levels of service over the
coming decades, and climate change only increases the need for additional resources”. Nantucket has been
impacted through all these water resources due to recent storm events and can “see” the impacts of a changing
climate. Nantucket also understands that mitigation to preserve and protect its resources is a sole source effort as it
has no regional neighbor to depend on.
Climate change is also leading to higher tides as was evidenced in downtown Nantucket where flooding was a major
issue when Sandy hit. New FEMA maps detail the further inland flood zones have changed to. Potential risks include
sea level rise, more intense storms with subsequent flooding, temperature increases, ecosystem change, habitat and
species impacts, and potential stormwater intrusion. The United States Army Corps of Engineers completed a LIDAR
survey of Nantucket’s coastline after the 2012/2013 storm events and details areas of impact on Figure 3-6. 3-7 and
3-8. These maps show areas where storms impacted the coastline areas, which gives the Town an idea of where this
CWMP Update Plan needs to integrate proactive planning with technical solutions to meet challenges presented by
climate change. For example, planning infrastructure in areas of vulnerability that will withstand future potential
impacts. This may mean locating pump stations well outside of coastal areas subject to high tides, flooding and
erosion. Planning to prevent public health risks as a result of sewer overflows or damage to and/or actual loss of
infrastructure with enhancements to protect the infrastructure should an event present itself in the future.
Based on recent evidence and studies done by the scientific communities, climate change is posing real challenges
and consequences to geopolitical boundaries. Presentations by the Woods Hole Institute scientists at the 1st Annual
Cape Coastal Conference, State of the Cape: Changing Waters & Shorelines in June 2013, detail impacts with
changing climate, seal level and coastal hazards on the Cape and Islands.
The recommended Plan included in this Report has taken aspects of climate change into account in the conceptual
planning, especially in the locating of collection system infrastructure. At this point in the planning process, it is
important to take climate change into consideration, but it is more important to move forward consistently and with
strategic planning in mind. When the Town moves forward with Final Design, a more comprehensive evaluation will
be taken and offset mitigation measures will be applied where needed. Final Design affords the town much more
detailed information, such as geotechnical data, that is not available in the planning or conceptual process.
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This CWMP Update recommends that the Town prepare a long-term strategy for dealing with climate change for the
preservation and protection of vital infrastructure, as well as provide a sound financial plan to maintain its
sustainability.
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5.FUNDING AND FINANCING
5.1 FUNDING AND FINANCING OPTIONS
State Revolving Fund Loan Program5.1.1
A user-friendly funding option for the Recommended Plan for Nantucket is public financing through the
Massachusetts State Revolving Fund (SRF) Loan Program. The SRF Program is administered through MassDEP
and affords communities low interest loans currently at 2 percent over a 20-year period. Additionally, the O’Leary
Legislation passed in 2008, affords projects that meet specific criteria the opportunity for 0 percent SRF loans.
O’Leary Senate Bill No. 2379 was passed in August 2008, with the initial intent of supporting MEP communities.
Nantucket wastewater projects included in this CWMP Update will qualify for this funding as long as they each can
meet the following requirements:
Complete a DEP approved CWMP1.
Applies for and is approved for construction funds to implement recommendations of CWMP between2.
CY2009 and CY2019 through SRF process
Total project cost does not exceed 35% of total costs of all projects on that year’s IUP (applicant cap)3.
Project intended to remediate or prevent nutrient enrichment of surface water or source of water supply4.
Applicant currently not subject to a DEP Enforcement Order (due to violation of nutrient-related TMDL, etc.)5.
Project deemed consistent with regional water resources management plan6.
Applicant has adopted land use controls (subject to review of DEP) that will limit wastewater flows to amount7.
authorized under zoning and wastewater regulations in accordance with approved CWMP
The SRF Program is financed through the Massachusetts Water Abatement Trust (Trust), which was established by
Chapter 275 of the Acts of 1989 (The Hayes Act), as amended (Chapter 29C). Under Chapter 29C, financial
assistance is offered to projects at one-half market rate. The General Court authorized additional funding (contract
assistance) to be paid by the Trust to “buy down” the interest to 2 percent. For wastewater treatment and collection
projects such as contained in this Report, design costs are ineligible for SRF financing. This cost is paid directly
through Town means.
Nantucket has on many previous occasions taken advantage of the SRF Program, so is well versed on the Program
requirements. The next period for submitting SRF applications is August 2014. Once the town has accepted and
approved the Capital Improvements Plan (CIP) contained herein, a decision can be made as to what projects should
be first for implementation and coordination completed to get an application or applications in by the August 2014
deadline. All avenues of funding under the SRF will be evaluated and pursued in order to bring the most cost-
effective option to the Town.
A CY2015 PEF is being submitted in August 2014 for potential funding for Somerset, Madaket and Warren’s Landing
Needs Areas sewer extension.
Additional Funding Opportunities5.1.2
All avenues of funding are being pursued at this time. The Town, with the lead of the Board of Selectmen and Town
Administration are working towards defining a financing plan that meets the needs of the enclosed Capital
Improvements Plan (CIP). Multiple financing scenarios are being evaluated including splitting the overall costs into
thirds; 1/3 to tax base, 1/3 to Sewer Enterprise Fund and 1/3 as individual property owners. Other scenarios included
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50/50 cost sharing with half on the tax base and half to the property owner, as well as 100 percent to the property
owner. These scenarios are only the beginning of financing discussions, with the goal of having the Sewer Planning
Work Group established by the Selectmen take this task further to refinement.
5.2 HOUSEHOLD COSTS
Individual Household Cost Scenarios5.2.1
This section estimates individual household costs associated with the sewering of the Needs Area. These estimates
reviewed the worst-case scenario where the property owner pays 100 percent of the total capital cost as the Town, a
50/50 split between taxes and property owners and thirds where 1/3 is to the tax base, 1/3 to the Sewer Enterprise
Fund and 1/3 to the property owner. The Town is in the infant stage of determining how to apportion the capital costs
of the project and has not yet made a definitive decision as to how to recover capital costs. The Town is working
through the Sewer Planning Work Group to develop and implement capital cost recovery options based on the
results of this CWMP Update. Historically, Nantucket has funded sewer expansion through the general tax base and
has reached out to look at various options, including apportioning through a combination of betterment, general tax
and the Sewer Enterprise Fund. The Town is planning on furthering this discussion with the assistance of the sewer
Planning Work Group. This ad hoc committee will delve further into the capital cost recovery options. At the time of
this report writing, no decision had been made as to how this would transpire. For discussion purposes only, some
sample individual household costs have been developed for the first phase priority-Somerset Needs Area. These
calculations only include the cost of construction as shown in this Report. Future decisions on betterments, etc.
could include not only construction costs, but, also, design, planning and any other costs associated with the Project
as per MGL Chapters 80 and 83. Table 5-1 details sample costs using user costs of 100 percent, 50 percent (with 50
percent on tax base), and one third (one third on tax and 1/3 on sewer) scenarios using both 0 percent and 2 percent
State Revolving Funds (SRF) to cover construction only costs of $13,284,000 or $52,300. per user.
Table 5-1: Individual Cost Scenarios for Somerset Needs Area
Somerset Needs Area 100 Percent on User 50 Percent on User One- Third on User
0 Percent SRF $217.92 Month $108.96 Month $72.64 Month
2 Percent SRF $264.58 Month $132.29 Month $88.19 Month
A detailed breakdown of existing debt would need to be calculated by the Town in order to estimate the tax burden
under the above scenarios.
There are various costs associated with the Recommended Plan to address wastewater needs that may including the
following:
Capital costs for the wastewater infrastructure, including force mains, gravity sewers, pump stations, low-
pressure sewers, engineering, legal, fiscal, administrative and contingency
Individual grinder pumps
Operation and Maintenance costs
-User Fees
Connection fees
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Individual sewer connections at the private property line
Potential plumbing and electrical upgrades
Pumping of and abandonment of existing onsite wastewater systems
The capital and annual operation and maintenance costs in this Report represent planning level costs. The estimated
capital costs for the Final Recommended Plan included herein are shown in Figure 3-21. Once the Town moves
forward with implementation of the Recommended Plan contained in this Report, a Final Design Report will further
refine costs.
Capital Costs5.2.2
Capital costs include furnishing and installing sewer pipes (gravity, low-pressure and force mains), pumping stations,
WWTF upgrades, engineering, legal, fiscal and contingency.
Individual Grinder Pumps5.2.3
In those areas where low-pressure sewers are recommended each property owner will be responsible for the cost to
install, operate and maintain individual grinder pumps. Located on private property, the grinder pumps convey the
building’s sewerage to the Town’s collection system for treatment at Surfside WWTF.
Operation and Maintenance Costs5.2.4
In addition to the capital costs for the sewer infrastructure as noted above, there will be an annual cost to the Town to
both operate and maintain the collection system. This cost is born by the users of the system under a “User Fee” as
described below. The Town apportions the operation and maintenance of the wastewater infrastructure, pumping
stations and divides it equally among the users. A User Fee is a charge for those properties that are connected into
wastewater infrastructure and this pays for the operation and maintenance of the system. This charge is typically
based on water usage.
5.2.4.1 Connection Fees
This is the connection fee that the Town typically charges to connect into the wastewater system.
5.2.4.2 Individual Sewer Connections (Private Property)
This is the cost born by the property owner to connect to the Town’s infrastructure. This cost will vary depending on
the property specifics – how far off the road, presence of trees, soil conditions for trenches, location of indoor
plumbing fixtures, etc. These costs will vary based on the site-specific situation.
5.2.4.3 Plumbing / Electrical Upgrades
These are potential costs to the property owner if upgrades on the private property need to be made either to
plumbing and/or electrical systems. For example, if a property owner currently has plumbing on the back side of the
building and the sewer is coming in from the front, the property owner may elect to re-route plumbing to the front to
limit costs. This same holds true for electrical costs - should the property need a higher amperage electrical service,
that upgrade may need to be made.
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5.2.4.4 Septic System Abandonment
This is a cost that every property owner will assume once sewer service in their area is operational at the time of
connection to the sewer. It involves a full pumping of the existing septic tank and either a removal of the tank or
cracking and filling with sand to completely abandon the system.
Based on the information gathered to date on conceptual costs and the fact that the Town has not made any
definitive decision on how it plans to appropriate costs, the estimated household costs are based on the afore-
mentioned methods of apportioning costs. While nothing has been officially approved, these three methods give the
Town a sense of affordability, both to the impacted property owner and the overall current and projected capital
expenditures of the Town that would impact the general tax base. The SPWG will carry this task further as it
evaluates all available capital cost recovery available both on a financial and political basis.
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6.PUBLIC OUTREACH
6.1 GENERAL
As part of the scope of this CWMP Update, the Town of Nantucket has conducted an extensive public outreach
program. The purpose of this public outreach/participation program is to inform the public of the scope and progress
of the planning study, to describe the results of the wastewater needs analysis and siting alternatives selection
process, and to encourage public input throughout the entire planning process.
The CWMP Update outreach has built upon the Public Outreach/Education Program initiated with the Wastewater
Action Plan that was developed by the Board of Selectmen and Town Administration in 2011. The Board of
Selectmen included the development of a “Long Term Wastewater /Water Quality Plan” in its FY12 Goals. These
goals included the following:
Develop and approve a five-year multi-phase wastewater implementation plan by 12/31/11
Conduct multiple wastewater workshops held by BOS on specific topics throughout the summer and fall of
2011
Seek funding at 2012 ATM for first phase of implementation plan
Continued implementation of Stormwater Management Plan
All of these goals have been realized as follows:
The Town implemented the Wastewater Action Plan in 2011 with the following:
-Conducted five Workshops; May, June, July, August and September 2011
-Set up a page on the Town’s website for all correspondence, information and information as to
reference documents. The Town continues to utilize this venue for posting all wastewater related
documents. The link to the site is http://www.nantucket-
ma.gov/Pages/NantucketMA_BOS/Sewer%20Info
-Developed and mass mailed a Wastewater Action Plan Newsletter to all Nantucket addresses.
Approved funds to complete this CWMP Update at 2012 ATM
Stormwater Management Plan on-going (Currently on the CY2014 Intended Use Plan for SRF Program
funding).
A Wastewater Action Plan Schedule was developed very early in the planning that outlined the milestones for
workshops and informational meetings. These included:
Board of Selectmen Workshops
-April 28, 2011 – Review of 2004 CWMP and Review of BOS Goals and Objectives
-July 13, 2011 – Madaket Needs Area Planning Update
-August 10, 2011 – Massachusetts Estuaries Program Update
Board of Selectmen Meeting Updates
-June 1, 2011
-June 8, 2011
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-July 6, 2011
-August 3, 2011
-September 7, 2011
-October 5, 2011
Working Group Meetings
-Held various times throughout the Planning process
Stakeholder Group Meetings
-June 13, 2011
Neighborhood Meetings
-July 11, 2011 – Nantucket Community Association
-July 16, 2011 – Non-Voting Taxpayers
-July 30, 2011 – Brant Point Association
-August 3, 2011 – Nantucket Garden Club
-August 6, 2011 – Tom Nevers Association
-August 17, 2011 – Rotary Club
-August 18, 2011 – Shimmo Association
The Wastewater Action Plan was widely attended throughout the summer and fall of 2011. All public meetings were
tapes for live and cable TV. The Workshops were interactive and encouraged participation, which aided the Town in
developing the scope for this CWMP Update.
6.2 PUBLIC MEETINGS, OUTREACH AND EDUCATIONAL SESSIONS
The Town has held multiple Public Informational Meetings on a variety of topics centered on the wastewater planning
starting with the wastewater Action Plan detailed above and it continues as of this report writing. This CWMP Update
was contracted in June 2012 and has continued to support the public outreach begun in 2011
The Board of Selectmen hosts a CWMP Update at one of its regularly scheduled meetings once a quarter. This is an
opportunity for the Board to not only present the results of the work being done, but afford those in attendance the
opportunity to get answers to any questions they may have related to the Project. Quarterly meetings have been held
on:
September 12, 2012
December 17, 2012
April 24, 2013
August 7, 2013
December 18, 2013
April 23, 2014
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The Board of Selectmen and Town Administration have hosted a number of meetings on the Massachusetts
Estuaries Program (MEP) with active projects in a number of areas on Island. On July 13, 2011, the Madaket / Long
Pond MEP was the topic of a Board of Selectmen Workshop, followed by a presentation from MassDEP on the Draft
Total Maximum Daily Load (TMDL) in October 2011. On August 10, 2011, SMAST and MassDEP were guest
speakers at another Board of Selectmen Workshop, explaining the MEP Program and how it has impacted
Nantucket.
SMAST completed the Draft Hummock Pond MEP in January 2014 and presented the results of this study on Island
on February 6, 2014. This meeting was taped for live and cable TV.
SMAST has the contract for the Town’s Annual Water Quality program working in conjunction with the Natural
Resources Department. After the yearly results are tabulated, a report is sent to the town detailing the Town-wide
results. On April 30, 2012, the Town hosted the University of Massachusetts at Dartmouth School of Marine Science
and Technology (SMAST) to present the Town’s 2012 Annual Water Quality Program results. SMAST and the
Natural Resources Department develop and implement the Town-wide water quality program with many of the
sampling areas included as part of the MEP and directly related to the CWMP Update. In addition to SMAST, the
Natural Resources Department presented its work completed for 2012 in conjunction with the water quality. This
meeting was taped for live and cable TV. All presentations and data are posted on the Natural resources Department
web page at http://www.nantucket-ma.gov/Pages/NantucketMA_NatRes/index.
SMAST presented the 2013 Annual Water Quality Program results at a public meeting in August 2014.
Once this CWMP Update is completed, the Town will continue to reach out with this Public Education Program in
order to maintain this very public project and keep the residents and taxpayers of Nantucket fully informed.
Coordination with the sewer Planning work Group with this The goal is to once again bring the project updates to a
variety of neighborhood associations in 2014 that may have an impact with the Project and are only on Island during
the summer season, as well as the general public. The website will continue to be maintained and public
presentations at the Board of selectmen will be on-going.
Copies of all outreach and educational information are included in Appendix L.
6.3 DEPOSITORIES
As part of the Public Participation Plan, the Town maintains copies of all CWMP Update information at the DPW at
188 Madaket Road, as well as posted on the Town’s website, wastewater page at http://www.nantucket-
ma.gov/Pages/NantucketMA_BOS/Sewer%20Info
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APPENDICES INCLUDED IN SECOND VOLUME
woodardcurran.com
COMMITMENT &INTEGRITY DRIVE RESULTS