HomeMy WebLinkAboutReview Of Proposed Sconset Beach Preservation Fund (SBPF) Beach Nourishment Project_201401231020339194REVIEW OF PROPOSED SCONSET BEACH PRESERVATION
FUND (SBPF) BEACH NOURISHMENT PROJECT
CONCLUSIONS AND RECOMMENDATIONS
Prepared For:
TOWN OF NANTUCKET BOARD OF SELECTMEN
Prepared By:
In Association with the Garrett Group, Ltd.
April 30, 2007
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REVIEW OF PROPOSED SCONSET BEACH PRESERVATION
FUND (SBPF) BEACH NOURISHMENT PROJECT
CONCLUSIONS AND RECOMMENDATIONS
TABLE OF CONTENTS
1. Introduction..............................................................................................................1
2. Role of Town Board of Selectmen...........................................................................1
3. FEIR Review............................................................................................................2
4. Project Impacts – Turbidity .....................................................................................3
5. Project Impacts – Nearshore Habitat.......................................................................4
6. Project Impacts – Borrow Area................................................................................5
7. Project Impacts – Construction................................................................................6
8. Project Impacts – Fisheries....................................................................................10
9. Project Impacts – Birds..........................................................................................10
10. Project Mitigation..................................................................................................11
11. Project Monitoring.................................................................................................12
12. Conclusions and Recommendations......................................................................12
Attachments
Attachment 1 Final Report of Findings – Third Party Peer Review of the Siasconsett
Beach Preservation Fund (SBPF) Beach Nourishment Project in
Nantucket, MA
Attachment 2 Representative Construction Photographs
Attachment 3 FEIR Technical Review
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1. Introduction
Applied Technology and Management, Inc. (ATM) was selected by competitive bid to
provide the Town of Nantucket, Board of Selectmen (BOS) with a review of the
proposed Sconset Beach Nourishment Project. This report summarizes key conclusions
and recommendations based on this review. Specific items requested within the review
included:
• Review of the Final Environmental Impact Report (FEIR)
• Review project data and information for accuracy, appropriateness, compatibility
and completeness
• Identify issues of public concern and means for the Town to address these
concerns
• Assess project feasibility and effectiveness, advantages and disadvantages for the
Town
• Confirm/Identify potential environmental effects
• Review the proposed monitoring program
In addition to the above elements, the ATM team staff have conducted to date an on-site
review of the project area with Town representation, and participated within two Board of
Selectmen meetings. Additional project information including the Notice of Intent,
project comments, and project vibracores were reviewed in support of this review effort.
2. Role of Town Board of Selectmen (BOS)
With regard to the proposed project, the Board of Selectmen (BOS) serves multiple roles.
As riparian property owners the Town BOS serve as Stakeholders within the project. As
representatives for Town the BOS also serve as representatives for all affected interests
within the Town including interests in support and opposition to the project. These roles
are further discussed within the companion review provided by the Garrett Group, Ltd.
and included as an attachment to this review.
Determination of whether the project benefits outweigh the impacts of the project is a
fundamental evaluation key to the regulatory review and ultimate approval (or denial) of
permits for the project. While approval by the local government (Town) is required, the
Conservation Commission (ConCom) is the most appropriate forum for this evaluation
and ultimate regulatory decision on the project. As a representative for all local interests,
the Town BOS should defer issues of a regulatory nature to the appropriate forums for
this determination and should encourage the full participation of all affected parties
within the process.
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3. FEIR Review
ATM has reviewed the FEIR and provides the following comments for consideration:
Completeness - By letter dated August 16, 2006 the Massachusetts Secretary of
Environmental Affairs determined that the FEIR is sufficient for the evaluation of the
project. The results of this review support the contention that sufficient supporting
information has been provided for the evaluation of this project. It is important to note
that while the FEIR has been determined to be complete, this determination does not
provide project approval but allows for vetting of the project by the appropriate
regulatory agencies (State, Federal and Local). Additional clarification and supporting
information will likely be required from the project sponsor as part of project regulatory
review.
Standard Practice and Due Diligence - The information, analysis and data provided
within the document are consistent with accepted practice for beach nourishment design
and evaluation. The level of care and due diligence delineated within the FEIR is to
accepted standards. The beach and borrow area designs have sufficient technical basis.
Detailed Review- As with all efforts of this magnitude and complexity, certain aspects of
the FEIR are lacking or open to critique. Specific items identified within this review are
provided as an attachment to this report. It is worth noting, however, that these items do
not detract from the inherent adequacy of the FEIR as a whole and would not materially
result in a significant change to the project design.
Project Need - Structures and property on the coastal bank are clearly vulnerable to loss
in their present state. The alternatives to address this vulnerability are limited and it is
reasonable to assume that without significant stabilization of the coastal bank, significant
and permanent loss of upland structures and property will occur.
Project Likely Effectiveness (Beach and Coastal Bank) – The proposed project will result
in the placement of a large volume of beach material and will create a beach of sufficient
size and dimension to provide significant storm and erosion protection to the base of the
coastal bank. Experience with numerous beach nourishment projects suggests that the
project should be largely effective in providing this protection. The coastal bank itself,
however, is currently over-steepened over large sections and will remain vulnerable to
slope failure. This vulnerability requires additional stabilization efforts independent of
the beach project.
Effects on Town property – The project will help to stabilize and reduce the loss of
Town properties within the project area. Town properties within nearby and adjacent
areas should remain stable or accrete due to the diffusion of sand into these areas from
the project area. The proposed dune at Codfish Park should increase the level of storm
protection for upland Town infrastructure and properties.
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Effects on the Town Sewer Beds – The proposed dune feature in this area should provide
additional storm protection to this upland facility. Additional shoreline accretion within
this area is likely due to diffusion of material from the beach placement area to the north.
4. Project Impacts – Turbidity
Given the volume of material required for this project and the rates of excavation and
placement, project induced turbidity is a concern of project construction. Based on our
review of the provided project information, the following comments are provided.
Magnitude of Concern – A review of the proposed borrow area, available geotechnical
data and project details suggests that while turbidity is always a concern with projects of
this type, the adoption of appropriate construction methodologies and monitoring
protocols should significantly limit the potential for excessive turbidity during
construction. This opinion is based on two primary observations. First, the silt/fines
content of the material is estimated to be on the order of 1%, which is notably low. For
comparison, beach quality material is generally required to contain less than 5% silt.
Additionally, though the silt content of the beach is low (less than 1%), the silt content of
the coastal bank material is significantly high (on the order of 10% or higher) and is
capable of producing natural nearshore turbidity events due to wave impacts on the bank.
As such, episodic turbidity events are a natural occurrence within the project area.
Contractor Oversight – Adequate construction protocols and contractor oversight are key
to limiting the potential for excessive turbidity. Standard construction practice requires
the implementation of temporary berm and diking within the disposal area to limit the
discharge of fines into the nearshore environment. With regard to this project, the SBPF
consultant team has the demonstrated technical expertise and experience to provide the
appropriate construction oversight of this project. Further, given the size of this project
the pool of contractors who are capable of constructing this project are limited to a few
select companies, all of which have significant experience with turbidity control
measures.
Monitoring Protocols – Adoption and implementation of an appropriate monitoring
protocol is required to ensure/verify that construction turbidity levels are within
acceptable standards. Specific monitoring requirements are generally prescribed by the
overseeing regulatory agencies and are included within the project permits. Standard
monitoring protocols have been defined for this type of construction. Given the specific
concern regarding turbidity within the hardbottom (fishing) areas within the vicinity of
the project, the adoption of a resource-based protocol is likely warranted and consistent
with current trends in regulatory requirements. This would require that the turbidity is
regularly measured during construction operations within the areas most likely to be
affected and of the most concern and that these measurements are used to evaluate the
effectiveness of turbidity control measures. Further, if measurements within these areas
indicate consistently elevated turbidity levels then the contractor would be required to
alter or cease construction operations to reduce the measured turbidity values within the
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affected areas. Given the concerns raised regarding turbidity, the adoption of some level
of independent oversight or review over turbidity measurements should also be
considered for this project. This would provide a level of confidence to the larger public
regarding project impacts.
5. Project Impacts – Nearshore Habitat
The project as proposed will result in direct, indirect and cumulative impacts to nearshore
cobble and hardbottom communities. Based on review of the project documents the
following comments regarding impacts to nearshore hardbottom are provided.
Direct Cobble/Hardbottom Impact – To some extent impact to nearshore hardbottom
communities is unavoidable given the requirements of this project. The extent to which
hardbottom is exposed within the vicinity of the project is a function of the availability of
sand within the area, and given that the area has exhibited significant erosion it is
reasonable to assume that hardbottom exposure will occur within the project footprint.
The project sponsor has developed estimates of direct coverage of these resources from
the proposed project. A review of these estimates indicates that they were determined
using acceptable methodologies and assumptions. Specifically, the project sponsor
concludes that the maximum direct coverage by the project will be on the order of 29.5
acres of hard substrate with a permanent loss of approximately 10 acres.
This review suggests that these estimates are reasonable for direct impacts within the
immediate influence of the project. Whether the level of impact is acceptable is a critical
element with the regulatory review, and it is the responsibility of the regulatory agencies
to make this determination.
It is important to note, however, that these estimates include a level of uncertainty
inherent within the assumptions required to make the calculations. The level of direct
coverage of nearshore hardbottom is a function of the beach grain size, wave conditions
and the magnitude of post-project erosion. While these can be reasonably projected,
post-project conditions may result in significant deviations from these estimates.
Therefore it is essential that a scientific-based monitoring protocol be adopted and
implemented prior to project construction. This protocol should be sufficient to
determine the level of pre-project hardbottom exposure and allow for the determination
of post-project exposure and level of impact. The project sponsor has provided a good
faith effort to provide this baseline data, though additional efforts may be required.
Project monitoring efforts are one element within the regulatory review and will be fully
vetted within this process.
Beyond the issue of direct impact, review of the project materials raises two important
concerns. The analysis of impacts provided in support of the project has focused on the
immediate vicinity of the project. While the analysis and baseline data within this area is
based on accepted norms for this kind of effort, limited information regarding the
potential for impacts outside the immediate project area has been provided. The project
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sponsor asserts that significant volumes of placed material will leave the project area due
to erosion and further contends that this will limit the magnitude and duration of impact
to nearshore hardbottom. This assertion, while reasonable, does not address the potential
for coverage as this material erodes from the project area to adjacent shorelines where
additional hardbottom not addressed within the efforts to date may be impacted.
Additionally, it is important to consider the issue of cumulative impacts to hardbottom
from the proposed project. While the impacts from the initial nourishment may be
limited, re-nourishment efforts will result in increased volumes of sand within the
nearshore system and over time the area of influence from the project and potential for
additional hardbottom impacts will increase.
In practice, the issue of cumulative impacts is a common concern associated with
nourishment projects. It is not necessarily reasonable to require the application to
account for all future and cumulative impacts for approval of the initial nourishment.
Additional nourishment efforts will require additional regulatory review for approval and
in principle project monitoring efforts will provide information critical to the assessment
of cumulative impacts. Delineation of pre-project conditions, however, is critical to these
efforts and must be conducted to a level sufficient to allow for these future efforts. As
such, the need for good, scientific based pre-project baseline data cannot be
overemphasized.
6. Project Impacts – Borrow Area
The following comments are provided regarding the proposed borrow area and associated
impacts:
Alternatives Analysis – The FEIR provides an alternative assessment for the choice of the
preferred location west of Bass Rip Shoal. The project sponsor rightly concludes that use
of an upland sand source is not an economical alternative. In terms of offshore sand
sources, the project sponsor provides a screening process that identifies the preferred
borrow area. While the evaluation of sand grain screening criteria (specifically the use of
a mean grain size vs. median) may be questioned, this screening alternative does provide
a reasonable determination of the proposed borrow area as the preferred alternative.
While arguments may be made for other alternative sites, a review of the available data
does not identify an argument that is particularly compelling for an alternate area from a
geotechnical, environmental or economic perspective. The analysis as presented appears
to have been performed in a manner consistent with accepted standards for alternative
analyses of this type. As the project sponsor, the SBPF has proposed the identified
borrow area as their preferred alternative. There are strong economic arguments to
support this alternative from their perspective and a review of the data does not indicate a
borrow site that would result in less impact than the proposed borrow area.
Level of Impact – Initial project construction will require a significant excavation of
material and will result in an essentially permanent change in the bathymetry within the
borrow area. A large excavation is required to construct the project and impacts from this
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excavation are unavoidable if the project is constructed. The excavation will have an
impact on the area, though the resulting excavation holes themselves may provide
compensatory habitat to replace to some extent what was lost. Regulatory review is
required to determine if the level of impact from the excavation is warranted relative to
the project need.
Infilling/ Post-Construction Recovery – Numerical modeling of the borrow area indicates
that some infilling will occur. While this analysis is within accepted standards for this
type of analysis it is worth noting that the level of uncertainty within this type of analysis
is fairly high. Given the magnitude of the excavation and the water depth it is likely that
infilling of the borrow areas will be low and on the order of magnitude of the model
predictions.
Material Compatibility – Based on review of the geotechnical data and inspection of the
cores taken within the borrow area, the material appears to be beach compatible and
appropriate for this project. The borrow material is similar to the native beach sand in
both geotechnical and aesthetic terms. Limited cobble is present within the cores but the
amount appears to be consistent with the native material.
Wave Impacts – The borrow area is located approximately three miles offshore. The
numerical analysis presented by the project sponsor indicates that wave modification will
be largely limited to a radius of two miles or less from the borrow area. The analysis
performed is to an acceptable technical standard for this type of evaluation and the
project sponsor’s contention that the borrow area will have a negligible effect on the
wave climate is a reasonable assertion consistent with observed performance and
standard practice.
Cumulative Impacts – Whether the level of impact required for the excavation is
warranted in light of the project need is a key issue within the regulatory/permitting
review of this project. Beyond the impacts of this excavation, the issue of cumulative
impacts is worth noting. It is the intent of the SBPF to renourish this project indefinitely
with offshore sand sources. These additional excavation events will result in additional
impacts. To some extent the issues of cumulative impacts can be addressed as an element
of future renourishment activities. Post project monitoring of this effort will provide
additional data on which to assess the impacts of future renourishment events and these
events will require additional regulatory review and approval. However, it is unlikely
that the issues of cumulative impact and the needs for additional sand sources will ever
be fully resolved and will continue to be an issue of concern regarding the project.
7. Project Impacts – Construction
Assuming project approval is granted, construction issues will present major challenges
to both the project sponsor and the Town. The realities of construction will require active
input and participation by the Town. As such, coordination and negotiation between the
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Town and SBPF will be critical to project success. The following comments are
provided regarding anticipated construction impacts of note to the Town.
Type of Equipment – The project may be constructed with either a cutter/suction head or
hopper dredge. While the project sponsor has stated that the use of a hopper is most
likely, they have not ruled out the use of a cutterhead dredge. Identification of the type of
dredge at this point is not necessarily required and it is not unusual for this determination
to be left to the dredging contractor. In comparison, there are advantages and
disadvantages to each type of equipment. These can be summarized as:
• Cutter/Suction Head Dredge - This method uses a dredge which essentially
vacuums up the dredge material and pumps it through a single pipe all the way to
the discharge point. This requires the placement of several miles of pipe, both
submerged and on the beach. The dredge remains within the borrow area and
uses a series of anchors and winches to move within the area. Turbidity within
the borrow area is less of a concern as the suction of the cutterhead tends to limit
turbidity. Turbidity at the project site can be more significant as the dredge can
have high production rates and can work for extended timeframes. The
production rate for cutterhead dredges is generally greater than for hopper dredges
allowing for project construction within a shorter timeframe.
• Hopper Dredge – This method uses a ship with dredging capability to excavate
material. Once full, the ship travels to the project area where a pipe in the
nearshore is used to pump the material onto the beach. Turbidity within the
borrow area may cover a greater extent, though turbidity within the discharge area
is less of a concern due to the limited production rates and inherent down time.
Given the volume of this project, the use of multiple hopper dredges and
potentially more than one discharge pipe may be considered.
Time of Year – The SBPF has indicated a preference for an end of May to October
construction window. This window would accommodate a February through end of May
restriction for Winter Flounder. The SBPF wishes to avoid winter construction citing
efficiency, cost and safety concerns. There is some legitimacy to these concerns as the
general meteorologic and wave conditions would significantly reduce production and
increase costs during the winter months and there are legitimate safety concerns.
Dredging contractors would prefer to not construct during the winter and this would be
reflected within the bid unit costs if winter construction were prescribed. It is likely that
winter construction would significantly increase the cost of this project.
The proposed construction window will result in construction activities during the peak
of the island tourist/usage season. While this may be unavoidable, it will have direct
impacts on the Town infrastructure and residents.
Construction Duration – The length of time required to complete the project is a function
of the dredge type adopted. Considering the volume of material proposed (on the order
of 2.5 million cubic yards), the contractor will likely need the entire construction window
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regardless of dredge type, and completion of the project within this window will be tight
at best. Downtime for equipment or weather could easily extend the construction
schedule beyond the proposed window.
Trucks and Equipment – The number of trucks required to mobilize and demobilize
equipment will vary depending on the construction methodology. The number of trucks
required, however, may be fairly large depending on the amount of shore pipe required
by the contractor. Assuming the worst case scenario (greater than three miles of shore
pipe) the project could require on the order of eighty truck deliveries to the site, and an
equal number of trips following de-mobilization. The number of truck trips required may
be reduced if less pipe is required on the beach by the contractor. Even with a reduced
number of truck trips it should be assumed that mobilization and demobilization will
have a significant impact on the Town’s infrastructure most notably the Town dock
facilities, roads to the project site and areas adjacent to staging areas at the project site.
Temporary staging areas will be required both at the Town dock and project area.
Mobilization and demobilization will require close coordination between the Town and
the contractor to limit the impact and inconvenience of these operations.
While mobilization and demobilization will account for the bulk of the truck trip project
requirements, regular fuel service to the project site will also be required. This impact
should be relatively low by comparison to mob/de-mob operations.
Major Holidays – Given that the current plan would span the entire summer season,
construction would coincide with Memorial Day, July 4th and Labor Day. As these days
and the associated weekends historically have high beach and waterway usage, additional
consideration of construction operations during these key times is likely warranted. At a
minimum, the Town should consider this issue in coordination with the SBPF to
determine whether additional restrictions on the contractor are warranted for these limited
timeframes. Beach access, road usage, security and public safety are all issues which
may require additional consideration during these key holidays.
24-hour construction requirement – The project will require 24-hour, seven day a week
construction. This will require approval from the Town, but is necessary to efficiently
construct the project. Impacts from nighttime construction will be limited to the
immediate area of construction.
Public Beach access – The project will limit beach access for the public within the
immediate area of construction. Adjacent areas would remain open. Access around the
project on the beach would be restricted. Given the limited existing public access within
the area, the restrictions on public access associated with the project are likely to be
minimal in extent.
Contractor Beach access – The contractor is limited to two areas for access to the beach;
Hoicks Hollow and Codfish Park. Both alternatives will have issues regarding this access
and it is likely the contractor will wish to use both to the greatest extent possible. The
use of Codfish Park is of particular concern for the Town as this is the main avenue of
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access to the beach for the public. Coordination between the SBPF, contractor and the
Town is strongly encouraged. The Town may also wish to consider restrictions on
contractor use of Codfish Park to limit the level of inconvenience to the general public.
Pipeline Corridors – Submerged pipelines will be required to transport dredged material
to the project area. For a hopper dredge configuration these will be limited to the
nearshore region adjacent to the project. For a cutterhead these would extend all the way
to the borrow area. Use of multiple pipeline corridors may be warranted and the
submerged line to the beach may be moved. Adoption of a pipeline corridor buffer area
around the critical fishing and habitat area could help to limit potential impacts to this
area and would allow for public usage of this area throughout the construction process.
Scarping – Following construction the beach will adjust to a more natural condition. As
part of this process material will migrate from the upper beach into the nearshore. This
will occur largely due to storm or wave events and will result in the formation of scarps
on the beach face. While beach scarping is a natural occurrence, the configuration of the
constructed beach exaggerates this process and can result in more scarping and larger
scarps than occur on a natural beach. Scarp formations several feet high are likely to
occur and may extend throughout the project area. Large scarps may impede beach
access and represent a hazard to the general public. Scarps may be mitigated by
mechanical means which generally requires a bulldozer to re-grade the beach face. It is
important that provisions to address beach scarp formations are anticipated within the
post construction phases of the project. A plan needs to be put in place to address scarp
formations when they occur and should be considered as a maintenance aspect of the
project.
Grade Stakes – Grade stakes are required during project construction to define the beach
dimensions. Provisions are required to prescribe and track grade stakes. Poor oversight
can result in the burial of significant numbers of grade stakes. Even with good oversight
practices a certain number of grade stakes will remain un-recovered following project
construction. These may be re-exposed within the beach face and can represent a
potential safety hazard. Re-exposure is particularly likely during storm/high wave events
when scarps form. As with scarp formation inspection and removal should be considered
as a necessary post construction requirement and a plan should be developed as a
maintenance element of the project.
Sesachacha Pond – The project will result in the accretion of the shoreline in the vicinity
of Sesachacha Pond. This will require an increased effort to implement pond opening
efforts conducted by the Town. The existing means and methods, specifically
mechanical excavation, will still be effective. The excavation volume requirement and
contractor effort will increase, though this increase is not likely to be substantial. This
incremental increase should be considered as an element inherent within the project
construction and should be addressed further in negotiations between the
Town and SBPF.
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Town Sewer Beds – The proposed dune feature will provide increased storm protection
to the Town Sewer Beds as well as additional Town properties and infrastructure. This
dune feature will require re-routing of an existing beach access point and re-vegetation.
Hurricane / Severe Weather Plan - The contractor will be required to submit a
hurricane/severe weather plan including protocols for equipment and personnel in the
event of a severe weather event. Review of this plan by the Town is recommended as it
is likely that the Town harbor may be identified for use as a safe harbor for storm events.
Aeolian Sand – The post construction beach will result in a wider, elevated and un-
vegetated beach berm that is susceptible to aeolian (wind-blown) sand movement.
Implementation of sand fencing and a dune re-vegetation program would help to limit
this sand movement. Low upland areas adjacent to the beach may experience increased
wind-blown sand following project construction. This is particularly true within the
Codfish Park area. This may result in an increased need for maintenance efforts.
Renourishment and Program Abandonment – Renourishment will require the re-initiation
of construction activities with similar impact to the Town. The SBPF fully intends to
renourish this project indefinitely. Abandonment of the project, however, would not
result in any additional remediation cost for the Town or SBPF, as without renourishment
the constructed beach would eventually erode to a state consistent with the present
(natural) condition.
8. Project Impacts – Fisheries
As stated previously, the project will have direct impacts to nearshore and borrow area
habitat. Monitoring and mitigation are proven strategies for addressing these issues.
However, the magnitude of impact relative to the project need must be fully weighed
within the regulatory process and it is the specific charge of the regulatory agencies to
make this determination.
Though not considered significant within the FEIR, there is an additional potential for
impacts to marine mammals from the project, particularly with the use of hopper dredges.
9. Project Impacts – Birds
Impacts to birds may occur both in the borrow area and in the nearshore. Impacts within
the borrow area are difficult to assess based on the available data as knowledge of usage
and data are limited. Historical nesting is noted at the boundaries of the beach project
area and within the potential area of influence of the project. The project sponsor
contends that the project will result in a net increase in potential nesting habitat. This
may indeed occur, though the creation of new upland beach areas does not guarantee that
these areas will be of high value or utilized at all for nesting. Efforts can be made to
improve the habitat quality of the constructed beach including re-vegetation. The long
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term net impact to nesting birds is difficult to determine based on the available data,
reinforcing the need for sufficient baseline data and monitoring protocols to assess
project performance.
10. Project Mitigation
The SBPF has proposed a mitigation reef to offset impacts to nearshore hardbottom
resources. The general concept of mitigative hardbottom as a replacement for impacts is
a generally accepted practice for nourishment projects. Regarding the current plan the
following comments are provided:
In-Kind Mitigation – A key intent of project mitigation is the replacement of habitat
impacted by the project. This requires that mitigation replace the key habitat functions of
the impacted areas. The current proposal utilizes concrete railroad ties as mitigation for
the natural hardbottom and cobble. While this will provide a hard substrate, it may not
replicate all of the functions of the natural habitat. Modification of this plan may be
warranted to improve the net quality of the mitigative habitat. Use of a reasonable
quantity of natural rock substrate in addition to the proposed railroad ties may provide an
economical alternative which would significantly address the in-kind mitigation concerns
regarding the mitigation reef proposal. Deployment of a range of reef types may also be
considered as an appropriate strategy as this will increase the diversity of the habitat. The
mitigation reef may also be presented as a case study for the effectiveness of hardbottom
mitigation for nearshore hardbottom impacts.
Proposed Mitigation Plan Review – Whether the proposed mitigation reef is sufficient to
offset impacts to hardbottom within the project area is an issue under the direct charge of
the regulatory agencies evaluating the project. It is likely that additional detail regarding
the mitigation plan is required to fully evaluate the plan. In particular, the specific areas
and water depths in which the reefs will be constructed must be defined.
Acreage/Coverage – The project sponsor proposes to construct approximately 17.7 acres
of mitigation hardbottom over a net area of 58.9 acres. Whether this acreage is sufficient
to offset the anticipated project impacts is a question which will be addressed within the
regulatory review process. The proposed acreage is on the order of magnitude of the
anticipated impacted area. Issues regarding in-kind mitigation and mitigation
functionality must also be considered within the evaluation of impact and mitigation
acreage. If the mitigation habitat is of a lower value than that impacted, a greater acreage
of mitigation may be required to fully offset the impact. Monitoring may also
demonstrate that the constructed mitigation is of lower habitat value than anticipated and
the level of impact to the project area is greater than anticipated. Hence the need for a
good scientific-based monitoring protocol is essential to addressing the suitability and
success of the project mitigation program.
Cumulative Impacts – Renourishment events may result in additional hardbottom
coverage not mitigated within the current mitigation plan. Movement of material to
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adjacent beaches may also result in additional hardbottom coverage. Project monitoring
will support post-project evaluations of both mitigation value and protect impact. Re-
evaluation of this issue will be required as an essential aspect to proposed renourishment
efforts.
Fisheries Compensation – Direct compensation to impacted commercial fisherman has
been proposed as an element of project mitigation. In principle this should be a last
resort and to the greatest extent possible efforts should be made to limit impacts. A
review of the existing project information suggests that construction methods and
practice can be largely effective in minimizing impacts to this stakeholder segment if
fully implemented. Mitigation for hardbottom impacts has the potential to significantly
compensate for habitat impacts and can result in the creation of new and viable fisheries
resources.
11. Project Monitoring
As previously stated, monitoring of the project is required before, during and after
construction. While the proposed monitoring protocols within the FEIR provide an
appropriate basis for monitoring efforts, review and approval of these protocols within
the regulatory process is required. Additional monitoring of areas, particularly those
outside the immediate area of project influence are likely warranted in order to
adequately account for long term and cumulative impacts.
Baseline monitoring data and protocols adopted for this project may also be expanded to
encompass greater extents of the Nantucket shoreline and can provide the basis for the
development of a comprehensive coastal monitoring and management program for the
island.
12. Conclusions and Recommendations
Based on the cumulative review and efforts conducted to date, it appears that all parties
with significant interests in the project are sufficiently represented within the review and
approval process. The regulatory entities charged with the vetting of the project appear
to have sufficient expertise and capability to fully and adequately evaluate the project and
its impacts. The project sponsors have adequate representation and technical support.
Project information is readily available and public participation within the project has
been noted. As such, the process of project review appears to be progressing in an
acceptable and appropriate manner.
With specific regard to the Town of Nantucket Board of Selectmen, the following
recommendations are provided for consideration:
• The BOS should encourage the active involvement of all Stakeholders within the
regulatory/approval process.
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• The BOS should continue active negotiations with SBPF regarding construction
issues and issues affecting Town properties. Assuming regulatory approval of the
project, coordination between the SBPF and Town will be required to minimize
construction impacts to Town residents.
• The BOS should fully support and endorse the regulatory review processes and
should defer questions of project approval to these bodies.
• In discussions and agreements with the SBPF, the BOS should retain ownership
rights to Town properties within the project area.
• The Town BOS should continue to pursue the adoption of public betterments
within negotiations with the SBPF. The One Beach initiatives currently under
consideration represent a significant project-related benefit to the general public.
• The Town should structure any agreement with the SBPF to limit the Town’s
liability for the project.
• Negotiations with the SBPF should address issues of increased and incremental
costs to the Town associated with the project.
ATTACHMENT 1
FINAL REPORT OF FINDINGS – THIRD PARTY PEER REVIEW OF THE
SCIASCONSETT BEACH PRESERVATION FUND (SBPF) BEACH
NOURISHMENT PROJECT IN NANTUCKET, MA
The Garrett Group, LTD.
280 Black Cat Road
Plymouth, MA 02360
phone (508) 747-3553 fax (508) 747-0052
April 26, 2007 JN 07-002
Messrs. Michael Jenkins, PE &
Gus Kruezkamp, PE
Applied Technology & Management
360 Thames Street, Unit 18
Newport, RI 02840-6631
RE: Final Report of Findings - Third Party Peer Review of the Siasconsett Beach Preservation Fund
(SBPF) Beach Nourishment Project in Nantucket, MA
Dear Gentlemen:
As authorized, The Garrett Group, LTD. (TGG) of Plymouth, MA has conducted a review of the
Regulatory, Biological Resource and the Proposed Mitigation Actions to be taken by SBPF (the
applicant) and presents our findings of their presentation the Board of Selectmen’s (BOS) review and
consideration.
TASK OVERVIEW
TGG has reviewed the project during a previous on-site visit with the team; from discussions at various
meetings, presentations and stakeholder comments; and by reviewing several key documents. These
documents include: portions of the Final Environmental Impact Report (FEIR), the Secretary’s Certificate
on the FEIR, Notice of Intent (NOI) filed with the Nantucket Conservation Commission (ConCom), the
Massachusetts Wetlands Protection Act and its Implementing Regulations (MGL c. 131, s. 40 and 310
CMR 10.00 et seq.), hereafter referred to as the WPA, and the Local Wetland Protection Bylaw and
Implementing Regulations (Chapter 136), the Town of Nantucket Beach Management Plan, and other
potentially applicable local Bylaws, all documentation will be cited throughout the narrative.
In general, the technical consultants for the applicants have completed a very professional analysis of the
proposed Dredging and Beach Nourishment Project at Sconset Beach, and have prepared comprehensive
documentation to advocate the project for their clients. This peer review is intended to advise the BOS, as
to project issues that require additional information or consideration, or require a greater level of response
from the applicant. This narrative will assist the BOS in identifying and evaluating the key issues, and
preparing the BOS to participate in all regulatory settings under public comment or public notice
opportunities, to voice the Town of Nantucket’s (the Town) position on the proposed project. After all,
the entire Town is their constituency. This narrative will identify key benefits and critical concerns to be
addressed. This narrative will not direct the Town to support or deny the project, but only how to
evaluate it, determine what is best for the Town, and how best to serve the public trust in representing the
Town’s position based on the applicant’s presentation of all of the facts required.
Messrs. Michael Jenkins, PE &
Gus Kruezkamp, PE
SBPF – Town of Nantucket: Final Report of Findings
April 26, 2007
Page 2
PROJECT DESCRIPTION
As the Secretary’s Certificate reads: “…the project involves the placement of approximately 2.6 million
cubic yards of sediment along 3.1 miles of the southeast shoreline of Nantucket for beach and dune
nourishment; mining the sediment needed for the initial nourishment from a 345-acre offshore borrow
site located approximately 2.7 mi east-northeast of Sankaty Head Lighthouse; bank terracing and
vegetative plantings on approximately 2000 linear feet of the coastal bank face; and the repair and use of
existing dewatering systems to increase the longevity of the nourishment”. The Secretary continued
relative to the Section 61 Findings (mitigation) that, “I find the FEIR to be adequate, and am allowing the
project to proceed to the state permitting agencies. The Final EIR contains adequate information on
alternatives, impacts, and mitigation, and allows the state permitting agencies to understand the
environmental consequences of their permit decisions”.
What is stated in the Certificate is a general, marginally quantitative project description which is
appropriate for the MEPA review level; however, now in the permitting phase, the project must be vetted
in a quantitative and performance-based review, at all jurisdictional levels – Federal, State and Local, as
implied by the Secretary’s comment. That last statement truly empowers the local Conservation
Commission (ConCom) to set the agenda for the entire permitting process.
In the NOI filed with the ConCom, page 4 of 9 of Form No. 3, presents the following quantified surface
area estimates for jurisdictional resource area impacts anticipated by the project:
1. Land Under Water and Land Containing Shellfish (or in laymen’s terms, ocean bottom) –
21,435,876 sf or 492+/- ac of ocean bottom.
2. Coastal Beach and Tidal Flat – 1,973,268 sf or 45+/- ac of intertidal shoreline.
3. Coastal Dune – 299,257 sf or 7.0+/- ac of migratory dune.
These 550+/- ac of jurisdictional coastal resources also support various natural, jurisdictional, economic
and recreational resources. As part of its project review the Town must weigh the benefits anticipated to
be realized from the completion of the project, against the costs (impacts) associated by implementing the
project; and the willingness and/or the success of the applicant to mitigate for those impacts. The BOS
must be prepared to present their opinions and findings at every opportunity throughout the regulatory
review (pre- through post construction periods). The applicant has identified their intended public benefits
to be realized by the Town on page 1-4 in Attachment One of the NOI; and the anticipated impacts of the
project, in Section 5 of Attachment A to the NOI. The Town needs to evaluate those intended benefits
and determine whether they are worth the anticipated impacts; impacts to be mitigated in the form of
protective (construction) and compensatory (restoration/replacement) of unavoidably lost resources; and
cumulative impacts.
The quantified impacts only represent the initial dredging and nourishment phase of the project, and do
not consider any cumulative effects. The NOI requests permission for additional dredging at a yet to be
Messrs. Michael Jenkins, PE &
Gus Kruezkamp, PE
SBPF – Town of Nantucket: Final Report of Findings
April 26, 2007
Page 3
identified borrow site and further nourishment in the project area, in five (5) years. This request for
additional work is made without any determination of specific need for the work, and without any
observational or monitoring data that establishes any level of success, or any occurrence of unanticipated
or unintended impacts, during the project’s first phase.
REGULATORY REVIEW
The overall premise of any regulatory review or alternatives analysis is based on three basic tenants that
include:
1. Avoid all avoidable impacts,
2. Minimize all unavoidable impacts, and
3. Mitigate for all unavoidable impacts that are anticipated and/or occur.
These tenants should be applied to any permit review, public/stakeholder comment and the issuance of
any permit. It is the responsibility of any applicant to establish by best possible means that whatever is
being proposed meets these three tenants.
In Massachusetts, there is a very complex, multi-jurisdictional regulatory process that needs to be
addressed. The following is a summary and discussion of that process. The applicant has acknowledged,
and the Secretary concurs, that proposed project will require various environmental permits that include
the following:
Federal Environmental Jurisdiction
Section 404/10 Permit Applications - Section 404 of the Federal Clean Water Act requires a permit for
the placement of any fill or dredged material, or any excavation in “Waters of the United States”,
including wetlands. In Massachusetts, a programmatic general permit process exists (MAPGP) for small
projects up to 1.0 ac of impact. Any, projects that exceed 1.0 acre of impact must apply for an individual
permit. Appendix A as attached lists and references the Functions & Values (F&V) that are evaluated for
any project that affect, in concert with quantified surface area impacts projects to the resources included
within the broad definition of “Waters of the United States”, and are the basis for the Federal no-net-loss
wetland protection policy.
Section 10 of the Federal Rivers and Harbors Act requires a permit for work or structures in or affecting
“Navigable Waters of the United States”, and include: any wharf, dolphin, weir, boom, breakwater, jetty,
or groin; bank protection or stabilization (e.g. riprap, revetment, or bulkhead); permanent mooring
structures (e.g. pilings); aerial or subaqueous power transmission lines; intake or outfall pipes;
permanently moored floating vessels; tunnels or artificial canals; boat ramps; aids to navigation; any
permanent or semi-permanent obstacle or obstruction; dredging or disposal of dredge material,
excavation, and filling; or other modifications affecting the course, location, condition, or capacity of
Messrs. Michael Jenkins, PE &
Gus Kruezkamp, PE
SBPF – Town of Nantucket: Final Report of Findings
April 26, 2007
Page 4
“Navigable waters of the United States”.
Section 401 Water Quality Certificate Application – Any discharge or placement of fill in
jurisdictional wetlands or “Waters of the United States or the Commonwealth”, with a surface area that
greater than 5000 sf, requires a Water Quality Certification (WQC) establishing that the proposed action
will not adversely affect or degrade the existing surface water quality assigned to the project area.
State Environmental Jurisdiction
MGL Chapter 91 License and/or Permit Application - All projects (dredging or structural) occurring
with AWaters of the Commonwealth@ including tidelands and historic tidelands require either a permit or
license under the Massachusetts Waterways Program (MGL c. 91 and 310 CMR 9.00). This would
include the placement of dredge material, fill, excavate and/or structure.
Federal Consistency Review - The Massachusetts Coastal Zone Management Office administers the
Coastal Zone Management Program and Policies, and ensures that proposed projects meet all appropriate
MCZM Management Program and Policies, and ensures that proposed projects meet with the policy
standards of the Federal and State Programs as defined in 301 CMR 21.00. When projects trigger a
Section 404/10 Individual Permit, they must demonstrate that the proposed project meets those
appropriate Federal policies.
Conservation & Management Permit – Since much of the project site is designated as a “Priority
Habitat…” for birds, should MassWildlife – Natural Heritage and Endangered Species Program (NHESP)
determine that the proposed project constitutes a Atake@ under Massachusetts Endangered Species Act
(MESA), then the project is subject to the restrictions and conditions of a Conservation & Management
Permit. Said restrictions and conditions may require the planning and management of the resource(s), and
the establishment of “Conservation Restrictions” on the project site (town-owned land).
Local Environmental Jurisdiction
The Notice of Intent/Order of Conditions - What is briefly mentioned in the Secretary’s Certificate is
the requirement for a permit (Order of Conditions) to be issued permitting the project from the local
ConCom. While this brevity may suffice for the Commonwealth’s purposes, it truly minimizes the
significance of the local action relative to the project design, and upcoming permit requirements (Federal
and State). The issuance of the OOC, that has avoided, or withstood appeal, that is registered at the
County Registry of Deeds, is the precursor to the issuance of all required wetland/waterway permits.
Federal and State jurisdictions desire to work with, and protect ConCom jurisdiction on local projects,
large or small. In Massachusetts, the receipt of the OOC is a very critical first step in the permitting
process.
Any activity conducted within the jurisdiction of the WPA or the Local Wetland Protection Bylaw
requires a filing of a NOI and the issuance of an OOC. This would include any work within the
protectable resources of the shoreline, the nearshore and the offshore areas, and work within the 100-ft
regulated Buffer Areas; under the jurisdiction of both the WPA (State Jurisdiction) and the Local Wetland
Messrs. Michael Jenkins, PE &
Gus Kruezkamp, PE
SBPF – Town of Nantucket: Final Report of Findings
April 26, 2007
Page 5
Protection Bylaw. Therefore, the NOI presents the applicant’s proposed APreferred Alternative@ to the
ConCom for their concurrent review under State and Local Jurisdictions.
While concurrent, these reviews can be separate and distinct since the WPA and the Local Wetland
Protection Bylaw have similar but distinct “Performance Standards” to protect those “Protectable
Interests” applicable to specific jurisdictional resources. The issuance of the OOC is also concurrent
under both state and local jurisdictions. The implications of the APreferred Alternative=s” proposed
activity within jurisdictional resources will determine the basis for approval or denial, and in the former,
the number of Conditions to be imposed, so that the project will meet the resource specific APerformance
Standards@. Appendices B and C, as attached, list the Performance Standards set forth in the WPA and
Local Wetland Protection Bylaw respectively. These are evaluated in concert with the quantified surface
area impacts of the project to the jurisdictional wetland resources. Conditions are developed by the
ConCom for the project to meet the specific Performance Standards. These are typically carried forth
through the Federal and State permitting processes.
The Massachusetts Department of Environmental Protection – Southeast Regional Office in Lakeville
(MADEPSERO) will review the technical, administrative, and procedural process for the review of each
NOI submitted to the local ConCom. MADEP=s review is concurrent with the ConCom process. Should
MADEP have reason to question the rationale or process for the issuing an OOC, they can do so during
the appeal period (10 business days following the ConCom=s issuance of the OOC). Should MADEP
choose to intercede and appeal the issuance of an OOC, the appeal is limited to the state jurisdiction under
the OOC. Other public/private concern(s) may appeal the issuance of any OOC, under either or both state
or local jurisdiction, should the municipality have a Bylaw, by registering said appeal MADEP (state)
and/or Superior Court (local), and with the support of any ten (10) taxpayers of the Commonwealth
during the appeal period.
Following the receipt of an OOC that has cleared the appeal period or has withstood an appeal; and is
recorded at the Registry of Deeds, several additional permits will be required before the implementation
of this project.
TOWN’S ROLES IN THE REGULATORY PROCESS
The Town has two roles in the review of the project. These include the role as a “stakeholder” and a
“regulator”. The Town owns the property where the proposed project actions are to take place (both on
and offshore). Ownership is immediately seaward of the mean high water line and extends to the three
(3) mile extent of territorial waters off the southeastern shoreline of Nantucket Island; and as the steward
of the public trust, use and benefits from said land; and as the head of the executive branch of Town
government, it is the responsibility of the Board of Selectmen (BOS) to represent the Town’s
“stakeholder” interest in this matter.
As the property owner, the Town can deny the applicant to the property, or can significantly influence
how the project can be implemented as a stakeholder. As the property owner, the Town can deny the
property access to the project, or can significantly influence how the project will be implemented.
Messrs. Michael Jenkins, PE &
Gus Kruezkamp, PE
SBPF – Town of Nantucket: Final Report of Findings
April 26, 2007
Page 6
The ConCom is appointed by the BOS, and is empowered to regulate jurisdiction of the WPA, by the
State law; and the local Wetland Protection Bylaw under Chapter 136-3 of the Bylaw itself. The
ConCom must review the project based on its ability to meet predetermined, jurisdictional resource
specific “Performance Standards” that have been established to protect all “Protectable Interests” of the
affected jurisdictional resource areas (Appendices B & C).
Care should be taken in applying the BOS responsibility to function as “stakeholder” during the
ConCom’s regulatory deliberations. While they are appointed by the BOS, their charge is specific to
implementing State statute and the Local Wetland Protection Bylaw, both with very specific limits of
jurisdiction, and not the more global view of the “stakeholder”.
The Stakeholder Role
The BOS, as the head of the executive branch of local government, has a mission statement adopted in
July, 2002 and amended May 9, 2006 that reads; “The mission of Board is to serve the community by
providing clear, concise goals and policies that ensure quality in the delivery of town services and
approved efficiencies in operating town government”. As part of the six BOS goals dated 2006-07, in
part, the BOS is to work to “Enhance the Quality of Life for Residents and Visitors [through] Improving
Public Access to the Waterfront”.
As stated clearly, the BOS has the charge of representing and overseeing how the project will effect
various municipal departmental operations and meet the goals, objectives and/or any “Performance
Standards” of several other local bylaws whose jurisdictions are affected by the project. These would
include the following Departments: Marine and Coastal Resources, Parks and Recreation, Police and
Fire, Public Works and Health. Specific local Rules, Regulations and Bylaws that may have jurisdiction
could include: Beach Rules and Regulations, Shellfish Rules and Regulations, Wharves and Waterways
(specifically Chapter 137.6), and the local Endangered Species Program. For many of these, the BOS
must consider the potential exposure (legal and economic) that the project creates for the Town, and
determine if the project benefits outweigh the costs, and is the anticipated project outcome is consistent
with the goals and objectives of each Town Department, Rule, Regulation or Bylaw.
As a stakeholder, the Town must represent the rights and interests of other Townwide stakeholders (e.g.
taxpayers, fisherman, environmental, etc.) by commenting during all “publicly or legally” noticed
processes (Federal, State and Local), whether for permits or licenses; and should exercise that right in
whenever possible.
The Regulator Role
The ConCom has a very critical role in the conditional approval or denial of the project via the OOC.
Again, the standing OOC under both the WPA and the Local Wetland Protection Bylaw, will serve as the
basis for all other permits and mitigation to be viewed and executed, as long as its preparation is
“Performance Standard” based, and not based on emotion.
Messrs. Michael Jenkins, PE &
Gus Kruezkamp, PE
SBPF – Town of Nantucket: Final Report of Findings
April 26, 2007
Page 7
Should the OOC be appealed under State Jurisdiction, then the appellant(s) would request that a
Superseding OOC (SOOC) be issued based on a project and site review by the MADEPSERO. Upon
issuance, the SOOC can be appealed to MADEP – Boston. At that point, the Commissioner and staff
review the project during an adjudicatory proceeding and then a Final OOC (FOOC) is issued by the
Commissioner. Should the FOOC be appealed, that appeal must be made to the Superior Court of Suffolk
County which is the jurisdiction where the FOOC was issued. Under the Local Wetland Protection
Bylaw, the OOC issued by the ConCom can only be appealed to the Superior Court of Nantucket County,
the jurisdiction where the OOC was issued. Typically the courts will wait until the state’s jurisdictional
appeal process has been completed. In any case whatever the final form that the OOC takes, it will serve
as the basis for all other permits and mitigation.
The applicant has correctly identified all on-site jurisdictional resources defined by the WPA and the
Local Wetland Protection Bylaw that will be affected by this project. These include:
Land Under the Ocean (LUO) – means all land extending from the mean low water line
seaward to the boundary of the municipality’s jurisdiction, including estuaries; the nearshore area
all being within the municipality and being less than 80 ft at this location.
Coastal Beaches (and Tidal Flats) – or all unconsolidated sediments subject to wave, tidal and
coastal storm action which form the gently sloping shore of a body of salt water and include Tidal
Flats. Coastal Beaches extend from the mean low water line landward to the dune line, coastal
bank line or the seaward edge of existing man-made structures, when the structures replace one of
the aforementioned natural features. Tidal Flats are any nearly level part of a Coastal Beach
which usually extends from mean low water landward to the sloping portion of the Coastal Beach
and can be separated from said beach by LUO.
Coastal Dunes – mean any natural hill, mound or ridge of sediment landward of the Coastal
Beach deposited by wind action, storm overwash, or artificial means; and serves the purpose of
storm prevention or flood control.
Barrier Beach – means a narrow low-lying strip of land generally consisting of Coastal Beach
and Coastal Dunes extending roughly parallel to the trend of the coast, is separated from the
mainland by a narrow body of fresh, brackish or saline water or marsh system, and may be joined
to the mainland at one or both ends. This includes the stretch of beach segregated from the
mainland by Sesachacha Pond as identified by MADEP.
Coastal Banks – mean the seaward faces or sides of any elevated landform, other than Coastal
Dune, which lies at the landward edge of a coastal beach, land subject to tidal action, or wetland.
Land Under Salt Ponds – means the submerged land surface beneath a shallow enclosed or
semi-enclosed body of saline water that may be partially or totally restricted by barrier beach
formation. Salt Ponds may receive freshwater from small streams emptying into their upper
reaches and/or spring into the pond itself. Division of Marine Fisheries (DMF) identifies
Sesachacha Pond as a Salt Pond.
Messrs. Michael Jenkins, PE &
Gus Kruezkamp, PE
SBPF – Town of Nantucket: Final Report of Findings
April 26, 2007
Page 8
Land Containing Shellfish – means LUO, Tidal Flats and Land Under Salt Ponds that contain
Bay Scallop (Argopectin irradians), Blue Mussel (Mytilus edulis), Ocean Quahaug (Artica
islandica), Eastern Oyster (Crassostrea virginica), Quahuag (Mercinaria mercinaria), Razor
Clam (Ensis directis), Sea Clam (Spisula solidissima), Sea Scallop (Placopectin magellanicus),
and the Soft-shell Clam (Mya arenaria). MDMF Growing Area and Classification Maps for the
project area and Sesachacha Pond are also included in Appendix B.
Land Subject to Coastal Storm Flowage – means all land subject to tidal flow or flooding
within calculated base flood elevation for the 100-year storm event by FEMA.
Estimated Habitat – are those lands and waters identified as designated habitats, set forth by
MassWildlife by procedure, that support state-listed species, where alteration of said designated
land or water, would have short- or long term adverse effects on the jurisdictional wetland
resource(s) and the specific state-listed species in question.
Each of these jurisdictional resources is deemed significant to provide up to eight (8) Protectable
Interests. Should any of these jurisdictional resources be affected by project work than it is assumed their
assigned Protectable Interests are also impacted. For a project to overcome the assumption that it is
impacting said Protectable Interests, it must meet the pre-described Performance Standards under both
state and local jurisdiction, and as presented in Appendices B & C.
RESOURCES OF SIGNIFICANCE
The project area supports several resources (jurisdictional, natural, commercial, recreational and seasonal)
that have been identified by the applicant and are clearly significant to the Town’s Economic,
Environmental and the Public health. Several of these resources also have regional significance.
These resources include:
1) Commercial Fishing (Inshore and Offshore),
2) Recreational Fishing (Surf, Inshore and Offshore),
3) Shellfishing (Offshore),
4) Public Beach,
5) Sankaty Head Coast Guard Light Station,
6) Domestic Waste Disposal Site,
7) Sand Source for Sediment Transport and far-field Nourishment,
8) On-going Beach and Bank Stabilization Projects,
9) Existing Endangered Species Habitats,
10) Jurisdictional Land and Water Resources.
Items 1-9 are economically significant to the Town as individual uses, attractions or destinations.
Therefore as the stakeholder, the BOS should advocate this point at every opportunity, and the need for
Messrs. Michael Jenkins, PE &
Gus Kruezkamp, PE
SBPF – Town of Nantucket: Final Report of Findings
April 26, 2007
Page 9
their protection or replacement by compensatory mitigation during the project. Less obvious resources
also exist such as the aforementioned Sesachacha Pond environment, the nearshore and offshore
invertebrate populations, the starved sand resources at the project locus and the effect of that condition on
downdrift shores. These must also be a concern of the BOS.
As an example and according to Nantucket (2006)1, Sesachacha Pond has clearly been identified as a
significant environmental asset of the Town. The Town has invested in managing and making sure that
the salt pond condition remains healthy as a salt pond. Even as the natural order would have the ecology
succeed to something other than a salt pond. As a stakeholder, the BOS must assure that the applicant
address this issue and make sure that the project does not adversely effect the pond management strategy
and the ability to assure that the bi-annual openings will continue unabated.
The ConCom as the local regulator, in concert with Federal and State regulators must regulate against
adverse effects to any of Items 1-9, as they are protectable, and the project must meet those specific
Performance Standards or F&V to the best of their ability protect those resources. Again, please refer to
Appendices A-C, to view those Performance Standards and F&V that must be addressed.
Sections 3 and 4 of Attachment A in the NOI present a detailed description of the biological and
jurisdictional resources that exist at the site.
Finfish exist in the nearshore and borrow site areas. Both of these areas are reported by the applicant to
be high energy areas relative to wave and surf action. Schooling pelagic baitfish and predators typically
aggregate in the eddies, between the high energy environments just off the surf zone. Demersals and
ground fish typically aggregate in the deeps adjacent to shoal waters. Fish will also tend to aggregate at
outfalls or stream mouths discharging to the sea. The sampling protocol and results that represent
existing conditions appear to be reasonable and expected. The shoreline along southeastern Nantucket
functions as a primary migratory pathway for adult fish moving along the coast. The species lists
including percent occurrence, Count Per Unit Effort (CPUE) , egg and larvae sampled, and months
present indicate a typical nearshore Finfish resource expected in the northern extreme of the Mid-Atlantic
Zone (zonal boundary extending west from Chatham, MA along the Connecticut shoreline to New York;
and from Chatham, MA offshore to the east. Winter Flounder (Pleuronectes americanus) as expected is a
species of specific attention.
The Nantucket Shoals is an area of shoal waters and deeps. Where these conditions exist, rips or short
jets of surface current over sub-tidal breaks in elevation occur. Rips serve to concentrate baitfish and
predators. Several have been identified by the applicant and the fisherman (e.g. Bass Rip and Quidnet
Rip) and some exist without specific designation, but do attract fish.
The Surf Clam is the dominant shellfish of the project area and supports a commercial fishery. The
predominant fishing methodology appears to be bottom draggers. As part of their fishing operations,
these draggers stir up the benthic sediments and more than likely cause some level of turbidity in the
1 Town of Nantucket. 2006. Sesachacha Pond Annual Report 2005. Marine and Coastal Dept. K. Conant,
March 2006.
Messrs. Michael Jenkins, PE &
Gus Kruezkamp, PE
SBPF – Town of Nantucket: Final Report of Findings
April 26, 2007
Page 10
offshore waters proximal to the borrow area during ambient conditions. Therefore, the biological
resources present should have some level of tolerance to temporal, low-level turbidity. The applicant
reports several other bivalves may be present in the nearshore and borrow area and include: Soft-shell
Clam, Quahuag, Eastern Oyster and Blue Mussel. These are more inshore species and would not be
expected as being significant species in the project area. Several other motile macroinvertebrate
(molluscs and arthropoda) exist at the nearshore and borrow areas.
Icthyoplankton and benthic infauna provide the basis and primary trophic levels in the aquatic food chain.
Their displacement or disturbance may require higher predators (finfish and shellfish) to temporarily or
permanently relocate to other feeding grounds.
Several areas of Cobble Bottom have been identified in the NOI, and represent patches of varied bottom
profiles and cover material set on coarse sediments. Their presence is more likely due to scouring by tidal
currents and wave action, and the starved nature of the shoreline due to the lack of sediments present or
available at this time. Such variation in cover provide opportunity for varies benthic communities,
fouling by algae and macrofauna to colonize, and is attractive to foraging fish.
Certain locations within the project area provide nesting and brood-rearing habitat for the Piping Plover
(Charadrius melodus) and the Least Tern (Sterna antillarum), both being state-listed species and the
former also being a federally-listed species. Both nesting above the High Tide Line (HTL) on broad
coastal beaches with gently-sloping fore dunes and blowouts between and behind the dunes that have also
been overwashed by storms. Dredging operations at the borrow site should not adversely affect
waterbirds since there is minimal habitat present and proximal alternative feeding locations are abundant.
Section 7 of the NOI – Attachment A provides the applicants presentation as to how the project meets
Regulatory Compliance. These should be reviewed in the context of the perceived intent of both the
WPA and the Local Wetland Protection Bylaw.
ANTICIPATED IMPACTS AND CONCERNS
The project as proposed will cause several unavoidable direct and indirect impacts and have been
categorized as follows:
Construction Impacts are those impacts caused by the mechanical implementation of the
project. The major impact of concern in any dredging or nourishment project is the physical
displacement of resources either by the removal or deposition of material. As stated in the NOI,
approximately 550+/- ac of biological and jurisdictional resources are to be involved with the first
phase of dredging and material deposition along the project area. Of concern here is that the
project application requests an initial dredging phase from an identified borrow area and the
resulting placement of the dredge material on the nearshore area of Sconset Beach; and a second
phase of re-nourishing of Sconset Beach in approximately five (5) years with dredge material
from an as yet to be identified borrow area. Therefore, increasing the quantified area of
displacement substantially; allowing an additional project to go forth without the benefit of
knowing whether the first project was conducted and performed in a successful manner; or did it
cause unanticipated or unintended consequences.
Messrs. Michael Jenkins, PE &
Gus Kruezkamp, PE
SBPF – Town of Nantucket: Final Report of Findings
April 26, 2007
Page 11
Should the Town support the project, a condition of approval should be that the project should be
“bracketed” to approve only the first dredging and nourishment phase of the project, then conduct
an extensive monitoring program to determine the success of the nourishment program, the extent
of recovery from any realized unavoidable construction impacts, and the ability of the overall
mitigation program to protect from and/or compensate for any realized and unavoidable
permanent impacts. The latter to be discussed later in this section.
In addition to the actual removal and deposition of material on resources, turbidity plumes arise
during dredging and deposal of material. One of the areas of displacement occurs within the field
of the plume itself, as it migrates and dissipates. As materials fall out of suspension they settle on
the bottom covering and potentially smothering immobile bottom resources. Thin veneers of fine
particulate material, as well as measurable thicknesses of coarser material can alter bottom
conditions within the plume footprint. Coarser particles will fall out of suspension closer to the
source of the plume than the fines and the silts. It is understood that there are very limited fines
in the source materials discussed for this project.
Lastly, displacement can occur by avoidance. This is typically temporal and is a behavior of
motile species that inhabit or transit a proposed project area. Each species has its own flight
threshold, or tolerances to stress and/or activity. Many species with short flight tolerance will
move away to other more suitable and available habitat relatively quickly. Other species with
longer flight tolerances will wait until they sense physiological stress before they leave (e.g.
stressed respiration or light deprivation).
Entrainment occurs when organisms (motile or non-motile) are drawn into the dredge head during
active dredging. Icthyoplankton, shellfish and benthic organisms are at the greatest risk of
entrainment; while larger more mobile species and life stages will avoid the dredge.
The proposed construction window should be of great concern to the BOS. The applicant
proposes work to occur during the period commencing at the end of May and extending through
November. Their rational for this schedule includes:
1. Meteorological and oceanographic conditions are prohibitively dangerous during the
winter season,
2. Allows for a breeding window from February to the end of May for the Winter Flounder,
and
3. Due to the project size, the proposed six (6) month project duration is necessary.
The BOS needs to address several key elements of their needs and responsibilities in determining
whether the applicant’s schedule is in the Town’s best interest. Several issues to consider
include:
The first half of the proposed construction window occurs during the height of the tourist season
Messrs. Michael Jenkins, PE &
Gus Kruezkamp, PE
SBPF – Town of Nantucket: Final Report of Findings
April 26, 2007
Page 12
on Nantucket, and the height of resource usage and activity.
- Greatest concentration of population and traffic on the island,
- Heavy fishing period (commercial and recreational) at the locus,
- Heaviest beach usage potential at the locus,
- Potential impacts to municipal infrastructure access and function during the
height of the season.
- 24 hour/7 day a week production schedule (heavy construction) during seasonal
property owners occupancy of abutting homes or renter occupancy of abutting
homes (noise and aesthetics), no all Siasconset residents are members of SBPF,
and
- Area limitations to land-based equipment mobilization/demobilization,
maintenance and movement due to increased island traffic and restricted island
access (e.g. available dock space and/or ferry access).
In addition, the first half of the proposed construction window occurs during the height of the
following:
- Biological resource production (land and water) along the Northwestern Atlantic
shoreline,
- Spawning of many other marine species, other than the Winter Flounder,
- Nesting and brooding of two (2) state – and one (1) federally listed species,
-
- Height of the northern migration of various finfish populations to the region, and
- Greatest nearshore population of motile shellfish and crustacean to the nearshore.
As a general rule when establishing construction windows, regulators attempt to address the
localized environmental issues over economic issues within reason.
The applicant states that conditions during the winter are “prohibitively dangerous” to conduct
offshore dredging. It is agreed that winter conditions are more harsh and difficult to contend
with; however, the limited number dredging companies capable of conducting this work, are
well-experienced in dredging during winter conditions since most dredging work occurs during
the fall, winter and spring throughout the region. While their proposed schedule attempts to
avoid the winter storm season it overlays the New England hurricane season. Hurricanes and
tropical storms may ravage the project area with the same frequency and intensity as nor’easters.
Aside from temperature and some winter surf conditions as variables, southeastern New England
appears equally susceptible to major coastal storm events in all seasons. Problems arise due to
interruptions in work due to weather events, and these operators have protocols for demobilizing
and securing projects during short-termed climatic episodes, and returning to operations rapidly.
Climatic interruptions tend to be more of an economic issue to the applicant, then a scheduling
issue.
The required project period (6 months) is not at question as part of this analysis. Should the
Messrs. Michael Jenkins, PE &
Gus Kruezkamp, PE
SBPF – Town of Nantucket: Final Report of Findings
April 26, 2007
Page 13
proposed construction window be permitted, then temporary cessation of work should be required
over the three (3) major summer holiday weekends.
Navigational concerns have been raised by representatives of the charter and commercial fleets as
the project is proposed to be conducted during the height of their season and in the same waters
that they fish. Concerns included project activities concentrated near the “rips” that are fished,
and the temporal navigational restrictions/limitations placed over “already” restricted fishing
grounds and fishing periods. A protocol, schedule and piping layout plan should be developed
for review and consensus prior to project implementation. Every effort should be made to place
offshore equipment and piping in limited locations and corridors. On-shore discharge point can
move with the need as they will have no effect on offshore navigation. Fewer offshore locations
and corridors can more easily be documented and marked with the approval of the Harbormaster
and/or the U.S. Coast Guard.
Permanent impacts are those irreversible changes caused by the project itself; after all of the
construction is completed.
As has been discussed, several biological and jurisdictional resources will be unavoidably altered
by the project. These alterations will include partial to total resource displacement, and
interrupted or impaired resource function and/or performance. The applicant requests
authorization of multiple work phases without presenting any additional borrow sources, and
without any observation or monitoring to determine the success of the nourishment program, the
extent of recovery from any realized unavoidable construction impacts, and the ability of the
overall mitigation program to protect from and/or compensate for any realized and unavoidable
permanent impacts.
In addition, when shorelines are actively managed, they require continued management. Beach
nourishment is not permanent; it is a temporary fix that requires on-going and future nourishment
operations and management. Several questions need to be addressed at the outset, but are not
limited to:
1. Cumulative impacts will occur during multiple phased projects, as is the case here.
However, the applicant does not offer much if any discussion on what is anticipated, or
how cumulative impacts will be monitored in the future.
2. What is the duration of the applicant’s (SBPF) funding stream for the continued future
management and nourishment of Sconset Beach ?
3. Should SPBF dissolve as an entity, who or what will replace it as a successor ?
4. Should there be no successor be identified, as the property owner, is the Town of
Nantucket required and/or willing to accept the responsibilities/costs for future work ?
5. Should there be no successor identified, and should the Town of Nantucket authorize
Messrs. Michael Jenkins, PE &
Gus Kruezkamp, PE
SBPF – Town of Nantucket: Final Report of Findings
April 26, 2007
Page 14
such work on their property, do they become legally obligated or responsible for future
work, or costs associated with rectifying impacts ?
6. If the answer to Question 3 is no, than is it worthwhile to permit such an aggressive and
expansive program to stabilize Sconset Beach, or to incur the anticipated and
unanticipated impacts, with future management or success in question ?
7. In addition, aside from beach nourishment, are there other less encompassing soft (non-
structural) practices that can be employed at the site, understandably practices with lesser
levels of success, to offset the proposed and anticipated impacts of the applicant’s
“Preferred Alternative”
Cumulative impacts are those permanent impacts that are associated with all aspects of the
project, can occur anywhere that is associated (tied to the project or project area in some way),
and compound over time. The applicant needs to propose how these will be monitored and how
their negative effects will be offset.
PROPOSED MITIGATION
As the Town deliberates as a “stakeholder” and as a “regulator”, consideration must be given to the
proposed mitigation program offered by the applicant. They also understand the cost/benefit relationship
of the project. Section 6 of Attachment A of the NOI presents the current mitigation package offered by
the applicant to offset anticipated unavoidable impacts. These include:
1. The applicant proposes a construction window (Late May to November) that provides
them with the required project duration, favorable climate (potentially), and avoids the
spawning period of the Winter Flounder. Is this the best timing for the Town and the
environment ? Pushing the schedule back three months appears to be better for the Town
and better for the environment as a whole, and would still meet the applicant’s and avoid
Winter Flounder spawning.
2. The applicant offers to harvest Surf Clams, assumed to be from the borrow area since the
text does not specifically identify the harvest area; then to relay and transplant sub-legal
sized clams to other local suitable shellfish habitat on Bass Rip, and to bring all legal
shellfish to market. A future re-seeding program in the borrow area should also be
considered.
3. To offset the loss of cobble bottom habitat, the applicant offers a plan to construct one or
more offshore artificial reef sites to expand the acreage of, and increase the amount of
hard bottom substrate in the area. While new and controversial in the northeast, many
successful artificial reefs exist all over the world. When planning these resources,
especially as compensatory mitigation for lost jurisdictional resource, regulators tend to
over think the design. Simply put, an artificial reef is any natural or unnatural material
Messrs. Michael Jenkins, PE &
Gus Kruezkamp, PE
SBPF – Town of Nantucket: Final Report of Findings
April 26, 2007
Page 15
placed in a subtidal environment that attracts fouling organisms, and creates a self-
sustaining patch community or ecology.
The applicant is prosing to provide 59+/- acres of hard substrate mitigation at various
locations as depicted on Figure 6-1 of the NOI package. Each location will provide for
20+/- acres of hard substrate. This mitigation is to offset those impacts to finfish resource
due to construction impacts and temporal recovery periods, and permanent losses of
existing hard substrate habitat. The applicant suggests that the benefits to be realized
include:
- Increasing Overall Habitat Diversity,
- Increasing Regional Habitat Diversity,
- Enhancing Recreational Fishing Opportunities, and
- Increasing Scientific Understanding of Beach Nourishment and Artificial Reefs.
Consideration must be given to the type and composition of materials used. A
combination of natural and man-made materials should be considered. As stated in the
NOI, care should be taken relative to the chemical properties of the man-made materials
uses (e.g. concrete), especially pH. Siting and placement issues, along with deployment
and anchorage systems must be addressed and well thought out. Depth and wave climate
are critical to appropriate sitting. Improper design and anchorage can cause these
systems to be torn apart, displaced, with component material(s) transported to
inappropriate locations.
4. A Marine Protection Observer has been suggested by the National Marine Fisheries
Service (NMFS) to be stationed on the offshore working platform (the dredge) to monitor
routes between the borrow site and the nourishment area to prevent ship strikes, during
construction activities observe the borrow and nourishment sites for the presence of
protected species, and monitor dredge material and document any entrained organisms
taken on board.
In addition, a third party construction observer(s) should be required to be stationed on-
site to monitor all construction operations and assure that all permit conditions and
approved operational performance standards are met. Should a condition or approved
performance standard be violated, that person should have the authority to shut down
operations until the problem is resolved.
5. The applicant will monitor during both the construction and post-construction periods to
document/verify the project area recovery from habitat related impacts.
Proposed monitoring will include:
Construction Period
- Turbidity, and
Messrs. Michael Jenkins, PE &
Gus Kruezkamp, PE
SBPF – Town of Nantucket: Final Report of Findings
April 26, 2007
Page 16
- Finfish response.
Post-Construction Period
- Cobble coverage in the nourishment area, and
- Re-colonizing of the Project Area.
Monitoring protocols and results should be reviewed by the Town or any authorized
representative.
6. The applicant is open to discuss financial compensation with the fishermen should they
demonstrate a material financial impact has been caused on their businesses, by the
project.
An essential part of any dredge project is the development of a Dredge Management Plan (DMP).
Typically, DMP’s are prepared by the selected contractor to address the conditions of all applicable
permits. However, there is precedent here in New England (e.g. The Boston Harbor Navigation
Improvement Project), for complex and/or large-scale dredging projects, where the applicant prepares a
DMP as part of the permitting process. This allows all agencies and interested parties to have an
opportunity to review and publicly comment on the actual operational manual to implement the project, as
part of the permits. The DMP will clearly establish all procedural elements and contingencies to
complete the project in full conformance with all regulatory requirements. While much of the
information required has been presented throughout the FEIR and the NOI, it must be organized into a
clear operational plan. The development of the DMP should occur as part of the permitting process and
should be referenced as one of the documents of record in each permit. The DMP should identify and
address several key issues including but not limited to:
1. The extent of the proposed dredging footprint(s), including future borrow sites,
2. All regulated resources within and adjacent to the dredging area,
3. Quantity of material to be dredged by each project phase and in total,
4. The dredging methodology and operational and mitigation protocols to be employed,
5. Detail all sedimentation and erosion controls to be implemented,
6. The location(s) and method(s) of disposal,
7. All mitigitive measures to minimize impacts,
8. A health and safety plan to protect the workers and the public at large (curiosity seekers),
9. Crowd control measures at the nourishment site (curiosity seekers),
Messrs. Michael Jenkins, PE &
Gus Kruezkamp, PE
SBPF – Town of Nantucket: Final Report of Findings
April 26, 2007
Page 17
10. Nourishment projects attract many birds (typically scavengers) at the discharge
location(s), a bird control plan becomes essential since their presence and concentrations
cause undesirable affects to the site and its surroundings,
11. Description of all safety contingencies, safety and informational signage,
12. A list of all responsible Personnel and Superintendents on-site during all operations, with
their qualifications and their individual contact information.
13. A list of specific operational and construction performance thresholds,
14. Project equipment requirements including pieces of equipment required, fueling,
maintenance and containment procedures, and
15. Emergency notification procedures (small island with limited resources).
A copy of which should be at every work station throughout the project; given to all personnel associated
with the project; and be on file with all local officials, public safety personnel, the Harbormaster, and the
U.S. Coast Guard. A copy of the plan should be included as part of the Construction Documents and Bid
Specifications during the Contractor Solicitation Process. The selected contractor should augment
company specific information as appendices to the DMP. Given the potential extended project life, the
DMP should be periodically updated as project elements or conditions change.
Messrs. Michael Jenkins, PE &
Gus Kruezkamp, PE
SBPF – Town of Nantucket: Final Report of Findings
April 26, 2007
Page 18
SUMMARY OF KEY RECOMMENDATIONS
The BOS has the responsibility to represent the interests of the Town, its constituency and its
departmental operations; as defined in its “Mission Statement” and “Goals and Objectives”. Several
issues have been discussed herein that fall within the BOS role as a “Stakeholder” and need to be
addressed during the upcoming publicly and/or legally noticed regulatory processes.
In summary, these key issues are listed again for your consideration.
1. Are the reported quantified surface area impacts of coastal resources acceptable to the
Town knowing that future project phases will cause added, yet unidentified surface area
impacts, and/or cumulative impacts ?
2. Has the applicant avoided all impacts where practicable, or have they minimized and
mitigated those unavoidable impacts, to the greatest extent practicable unavoidable
impacts?
3. The BOS should be noticed and copied on all matters related to this project.
4. Is the BOS willing to accept any responsibilities, potential liabilities and cost for future
operations and management of the program, should it be necessary ?
5. The BOS should charge the Town’s legal council to prepare documents to indemnify and
hold harmless the Town from any legal responsibility associated with construction,
permanent and cumulative impacts caused by the project.
6. The BOS should comment and raise concerns when it is determined that the project may
adversely affect any portion of the Town.
7. The BOS may want to consider extending this, or hiring an existing third party peer
consultant to serve as a technical advisor throughout the construction and post-
construction phases of the project.
8. The project must adhere to, or be granted waiver from adhering to all required
jurisdictional resource functional and performance thresholds.
9. The ConCom has a critical role in drafting an OOC that is fair, yet sets the tone for all
other permitting under State and Federal jurisdiction. Permitted activities and impacts
should be governed all relevant performance standards and/or threshold limits.
10. Several significant environmental and economic resources exist in the offshore and
nearshore project areas, and special concerns should used in considering the protection
of, or mitigation for these resources.
11. Consideration must be given to establishing an appropriate construction window that is
Messrs. Michael Jenkins, PE &
Gus Kruezkamp, PE
SBPF – Town of Nantucket: Final Report of Findings
April 26, 2007
Page 19
workable to all concerned.
12. The development of an approvable and amendable Dredge Management Plan as part of
the permitting process is recommended by TGG.
13. Navigational concerns need to be vetted through the applicant, the marine community
and the boating public; and the resulting actions should be clearly spelled out by the
Harbormaster and U.S. Coast Guard.
14. Should any, or all elements of the proposed mitigation fall short of reasonable
expectation to protect and compensate for impacts or resource losses; reasonable and
additional mitigation (construction and compensatory) should be required; and the
applicant or any successor fail to complete the work, then a pre-negotiated compensation
fund shall be provided by the applicant and held in escrow, to guarantee that critical
mitigation be completed; as a condition of all resource based project permitting.
15. Lastly, if approved, the project should be “BRACKETED” to a single dredging and
nourishment phase until suitable monitoring and observational information confirm the
predicted success of the project and the resulting mitigation.
Hopefully this narrative will assist the BOS in understanding and being proactive throughout the project.
The Town and it citizens look toward the BOS for leadership and guidance throughout the project. This
narrative should also support the needs of Applied Technology and Management, as part of their overall
review. Please contact me for any questions that you may have. Thank you for your time and
consideration and the opportunity to participate in the project.
Respectfully,
THE GARRETT GROUP, LTD.
Marc J. Garrett
Principal Investigator
appendices
ATTACHMENT 2
REPRESENTATIVE CONSTRUCTION PHOTOGRAPHS
The following photographs are representative of typical beach nourishment operations
and were taken in April 2007 in Indian River County, Florida. They are presented here
for informational purposes and to provide a better understanding of the elements that
would be required for project construction. This project consisted of the placement of
approximately 300,000 cubic yards of material from an offshore shoal sand source. A
combination of two hopper dredges was utilized.
Figure 1. Upland Beach Access/Staging Area. This site is representative of the staging
area required at the beach access site. Fuel delivery activities are occurring in the photo.
Pipe sections are also visible in the background.
Figure 2. Close-up of Stockpiled Beach Pipe Sections. Pipe sections are typically 40
feet long by 30” diameter and are generally stockpiled in strategic locations for use on the
beach. Typically 6 sections of pipe can be transported by flatbed truck and an end loader
is required to move the pipe.
Figure 3. Beach Discharge Location. Note security fencing in foreground. Equipment
and pipe storage and staging is present. Discharge occurs in the vicinity of the two
bulldozers.
Figure 4. Close-up of pipe discharge. The two bulldozers are required to grade the
placed material, direct the discharge, and maintain the construction dikes. These
operations occur 24 hours per day, 7 days per week.
Figure 5. Discharge Pipe Beach Landing. The submerged pipeline from the dredge
extends up the beach and is connected to pipe sections that extend down the beach as
construction progresses. The beach shown in this photo was constructed from the dredge
material.
Figure 6. Hopper Dredge and Pumpout Booster. The pumpout hook-up is located in the
nearshore in water depths sufficient to allow the dredge to hook to the discharge pipe. In
this case a booster pump on a jack-up barge is utilized to extend the range of the pumpout
discharge. This dredge (The Dodge Island) has a hopper capacity of 3,600 cubic yards.
Active pumpout is occurring within the photo. Note the presence of turbidity within the
immediate nearshore.
Figure 7. Finished and Graded Beach Face. Note the construction/discharge operation
in the background and the grade stake in the foreground.
ATTACHMENT 3
FEIR TECHNICAL REVIEW
FEIR Technical Review
The following provides a critique of key elements within the FEIR technical
documentation. As stated within the report body the FEIR effort as a whole is to
accepted standards, and the critique provided here does not alter the fundamental
conclusions or project design.
Grain Size Compatibility (Section 4.1.1) – The document provides mean estimates of
native and borrow area grain size and percent silt. Additional statistical data, specifically
the median grain size would be useful in evaluating grain size compatibility. Given the
presence of cobble/pebble within both the borrow area and native sand, the use of a
median statistic is likely more appropriate. The coarse fractions may skew the mean
determination that is representative of the sand fraction. Sediment distribution curves
would be helpful in evaluating geotechnical characteristics.
Physical Monitoring Surveys - The physical monitoring protocol prescribes a survey out
to a minimum depth of -30 feet. Given that the proposed depth of closure is -26 feet, an
offshore extension of the profile is warranted to ensure full closure of the profile. This
should be prescribed in terms of a minimum depth and a minimum distance offshore to
ensure that the full active profile is covered including any shoal interactions. The current
protocol calls for profiles over a five mile lineal extent. Given that the project is on the
order of three miles, this represents an approximate extension of monitoring on the order
of one mile to the north and south of the project. This distance is insufficient to capture
the full, long term impact of the project on adjacent shorelines and should be expanded to
cover the entire impacted littoral cell. The density of profiles can be reduced with
distance from the project, but a good pre-project baseline across the entire littoral cell is
required to fully assess project impacts.
Model Calibration - Model calibrations for the wave, transport, and shoreline modeling
components have not been provided. This limits the ability to fully assess the predictive
value of the models. While the availability of data to calibrate the models may be
limited, the calibration process is critical to model development and should be fully
presented within the model analysis. Un-calibrated or poorly calibrated models do not
provide the same level of certainty that a well-calibrated model provides. The design
cross-section is based on SBEACH modeling which can be very sensitive to the choice of
model calibration coefficients. Shoreline modeling (both GENESIS and Delft 3D)
require calibration coefficients that strongly influence model results. Review of the
shoreline modeling further emphasizes this concern within the area of Codfish Park.
Available data indicate significant accretion within the vicinity of profiles 83 and 84.
This accretion trend is not represented within either modeling effort and the models
suggest an erosion trend in these areas. As these models are presented as support for the
project performance, the ability of the models to adequately replicate erosion and
accretion trends is central to their application in support of project performance.