HomeMy WebLinkAbout26 SE48_3115 SBPF Response to 02-11-19 Public Comments
PRINCIPALS
Theodore A Barten, PE
Margaret B Briggs
Dale T Raczynski, PE
Cindy Schlessinger
Lester B Smith, Jr
Robert D O’Neal, CCM, INCE
Andrew D Magee
Michael D Howard, PWS
Douglas J Kelleher
AJ Jablonowski, PE
Stephen H Slocomb, PE
David E Hewett, LEED AP
Dwight R Dunk, LPD
David C Klinch, PWS, PMP
Maria B Hartnett
ASSOCIATES
Richard M Lampeter, INCE
Geoff Starsiak, LEED AP BD+C
Marc Bergeron, PWS, CWS
3 Mill & Main Place, Suite 250
Maynard, MA 01754
www.epsilonassociates.com
978 897 7100
FAX 978 897 0099
21597/2018/Expanded Project/NOI/Public Hearing Comments
March 1, 2019
Nantucket Conservation Commission Via Electronic Mail and U.S. Mail
2 Bathing Beach Road
Nantucket, MA 02554
Subject: Response to Comments from the February 11, 2019 Hearing on the
Expanded Baxter Road and Sconset Bluff Storm Damage Prevention
Project (DEP File No. SE 48-3115)
Dear Commission Members:
On behalf of the Siasconset Beach Preservation Fund (“SBPF”), Epsilon Associates,
Inc. (“Epsilon”) submits additional information on the topics raised by Nantucket
Conservation Commission Members and public comments during the Nantucket
Conservation Commission (“Commission”) February 11, 2019 Public Hearing for
the Expanded Baxter Road and Sconset Bluff Storm Damage Prevention Project
(“Expanded Project”).
These written responses provide additional information to augment verbal responses
on these topics made by SBPF team members during the Public Hearing, as
applicable. The topics addressed herein also respond to the verbal and written
comments submitted by the Nantucket Land Council, Inc. (letter dated 11 February
2019 reflects verbal comments) and the Quidnet Squam Association (letter dated 11
February 2019 reflects verbal comments). Throughout the Public Hearing process
Project opponents have presented opinions not supported by fact, or predicted
future damage to coastal environment from the extension Project. In response, the
SBPF and their consultants have responded using observations and data collected
pursuant to the Order of Conditions (“OOC”) plus engineering analyses to design
the Project. It is incumbent upon the Commission to make an evidenced base
permitting decision, and cull out the opinions and commentary, and rely on data
and observations to make a decision; and to write pragmatic special conditions to
protect the interests of the Wetlands Protection Act and Nantucket Wetlands Bylaw.
During the review and permitting process for the existing Project (SE48-2610 and
SE48-2824), the Commission and the Massachusetts Department of Environmental
Nantucket Conservation Commission 2
Re: DEP File No. SE 48-3115
March 1, 2019
Protection (“MassDEP”) relied on coastal science interpreted and applied to the
Siasconset Coast, as well as engineering analyses to make those permitting
decisions. For the current Expanded Project, the Commission has several years of
site specific data plus coastal science and engineering analyses from which to make
a decision. Shoreline monitoring to date has not shown damage to on-site or
adjacent resource areas, and the performance of the geotube system supports the
efficacy of the geotube system as a long-term Coastal Bank stabilization technique.
Remedial action has been proposed and approved by the Commission to address
return extensions, and lessons learned over the past several years are reflected in the
minor design modifications and sand template management proposed for this
Expanded Project (SE48-3115).
Comments made during the 11 February 2019 Public Hearing probed no issues not
previously raised during earlier Pubic Hearing sessions. Therefore, below we
present the major topics of discussion from the most recent Public Hearing session
in italics typeface followed by our response in normal type face, with references to
materials previously submitted to the Commission as applicable.
1. Sea Walls Will Always Cause Harm
a) The geotubes are causing accelerated erosion in front of and on the ends of
the project. When the covering sand is washed away the exposed geotubes
cause scour like any hard sea wall.
This assertion is not supported by shoreline monitoring data. See responses
submitted to the Commission on 02 November 2018, 30 November 2018 and 04
January 2019, as well as the presentations on 05 November 2018 which address
erosion rates. There is no evidence of accelerated erosion post-geotube
construction that exceed historic observations. The ongoing maintenance of the
agreed-upon sand-mitigation system is credited with preventing the impacts that
might otherwise occur.
b) Photographs contradict SBPF explanation and show significant scour and
flanking at the Northern and Southern ends in the March storms.
The succession of intense storms in March 2018 underscored the need to manage
the geotube ends on a periodic basis. As a result of observations in March 2018,
SBPF requested an OOC Amendment, which was approved on 28 November 2018.
The Amended OOC authorized adjusting the end returns to compensate for
continued erosion adjacent to the geotubes. Left unaddressed the ends would
become problematic. However, by managing the ends through a program of
Nantucket Conservation Commission 3
Re: DEP File No. SE 48-3115
March 1, 2019
periodic extensions of the returns, as was approved in November 2018, flanking
and end scour can be controlled. The location of the clay head at the northern end
exacerbated the northern condition, something that should be managed with the
extended returns to be installed.
c) Your own data show that the beach is clearly eroding faster than it did
before.
This has been asserted many times during the Public Hearing without reference to
the dataset in the record. Rather the commenter selects a single profile or a single
discrete time period to assert this opinion. As described in several previous
submittals, and most recently on 04 January 2019, this statement is not supported
by the monitoring dataset. The quarterly surveys report a dynamic shoreline
documenting erosion and accretion over various periods of time and portions of the
shoreline. One might also generalize from a single selected profile and/or discrete
time period and demonstrate that the beach is accreting, which is clearly not the
case. See the Southeast Nantucket Beach Monitoring, 77th Survey Report dated
September 2018 (“77th Survey Report”) which documents the variations is shoreline
change over time.
d) The walkable beach is not being monitored and will disappear.
This is an erroneous assertion. The walkable beach fronting the existing geotube
system is being monitored, and it is maintained by sand eroding off the sand
template as well as input from the littoral drift system. If that stops being the case,
the failure criterion will be triggered. Monitoring and a failure criterion of a
walkable beach is also suggested for the Expanded Project.
Review of profile data in the 77th Survey Report fronting the existing geotube
system, Profiles 91 and 91.5, show significant accretion (greater than 20 feet)
following the erosion event in the winter of 2012-2013, then some loss over time as
that large sediment volume was washed into the littoral system. Then another
period of accretion (approximately 20 feet) from the large volume of sand off the
template during the winter of 2017-2018 and minor loss as that sand washed into
the littoral system. The shoreline in front of the existing geotube system appears to
be stabilizing within a defined band since 2007.
Nantucket Conservation Commission 4
Re: DEP File No. SE 48-3115
March 1, 2019
e) Berman’s statement that the expanded geotube project represents 7% of the
10-mile eastern coastline means that there will be a 7% reduction in the
amount of sand material contributed to the littoral system.
That argument along with a spurious analogy about a 7% loss in a pay check,
completely neglects the volume of mitigation sand contributed off the template,
onto the Coastal Beach and into the littoral drift system.
As documented in the response to comments document dated 16 November 2018
and as presented during the 01 October 2018 Public Hearing presentation, the
mitigation sand volume exceeds that contributed by the unprotected Coastal Bank.
The template was documented to contribute about 20 cy/lf during the 2017-2018
sand year, and the annual average contribution of sand off the template is 13.5
cy/lf/yr (2016–2018) since construction was completed. This compares to the
historic (1994 - 2013) pre-construction contribution rate of 12-14 cy/lf/yr. Note, the
1994–2013 period includes the large erosion event of 2012-2013. The adjacent
unprotected Coastal Bank contributed approximately 17 cy/lf during the 2017-2018
storm season, and an average annual rate of approximately 8 cy/lf/yr during the five
years between 2013-2018. The sand off the template is mitigating for the placement
of the geotube system in front of the Coastal Bank and not resulting in a net loss of
sand to the littoral drift system
2. Sand Supply Volume
a) The amount of sand being supplied as mitigation is substantially less than
the amount that was washing away from natural erosion.
This is not true. The sand contribution methodology follows the procedure
established by MassDEP and the Massachusetts Office of Coastal Zone management
(“CZM”), and this was confirmed by Mr. Berman engaged by the Commission for
technical review assistance. The data used to calculate the existing Project rate was
based on 23 years of record, which includes the large erosion event during the
winter of 2012–2013 (no undercounting by the Applicant) and was determined to
be 12–14 cy/lf/yr. The annual average volume of sand contributed off the template
for the period 2013–2018 was 16.5 cy/lf/yr which includes construction years (see
the Public Hearing presentation from 01 October 2018), or 13.5 cy/lf/yr for the post-
construction period (2016 – 2018), see correspondence dated 16 November 2018.
Thus, the existing geotube system is contributing a volume of sand commensurate
with the pre-construction unprotected Costal Bank, i.e. natural erosion.
Nantucket Conservation Commission 5
Re: DEP File No. SE 48-3115
March 1, 2019
For the proposed Expanded Project the appropriate methodology to calculate sand
contribution was used and the length weighted average annual erosion volume was
calculated to be 8.8 cy/lf/yr using the same data set, which includes the 2012–2013
erosion event. Thus, the adaptive mitigation protocol, see response below, will
provide an equal or greater volume of sand as the natural unprotected Coastal Bank
would have.
b) The adaptive sand mitigation plan means that the sand mitigation volume
would be reduced to the “annual average.”
This is not how the adaptive sand management program is designed to work. If the
Applicant wanted to contribute only the annual average volume then they would
have proposed 8.8 cy/lf/yr. A fixed annual mitigation sand volume was not
proposed in the NOI nor any subsequent submittals.
The proposed Template Sand Replenishment Protocol is proposed to contribute the
“right” amount of sand to the littoral system, as termed by Mr. Berman. Review of
the Template Sand Replenishment Protocol, submitted 02 November 2018, shows
that the template would contain a supply of 22 cy of sand per lf of template at the
start of each storm season. Exposed geotubes would be re-covered after erosion
events, with no maximum sand volume established. Should additional sand be
needed during a given storm season to cover exposed geotubes, i.e. more than 22
cy/lf is used, then more sand will be imported to comply with the re-covering
requirement.
c) You are building to 100-year storm but only mitigating for average year. In
years with a lot of erosion the system would be left short.
This understanding of the proposed Template Sand Replenishment Protocol is
incorrect. As described numerous times during the Public Hearing process, the
template would contain 2.5 times the length weighted average contribution rate (22
cy/lf vs. 8.8 cy/lf) in the template, i.e. an on-site stockpile. In this way there is a
stockpile available to contribute 2.5 times the average annual expected erosion
amount. But the commitment for sand mitigation does not stop there. As explained
several times should additional sand in excess of the 22 cy/lf of sand on the
template be needed during a given storm season to cover and re-cover exposed
geotubes, then more sand will be imported to comply with the re-covering
requirement. Thus, even in very active storm seasons that require more than 2.5
time the average, the system will not be left “short.”
Nantucket Conservation Commission 6
Re: DEP File No. SE 48-3115
March 1, 2019
d) During some storms as much as 30 feet of unprotected bluff can be lost.
This means that the amount of sand to replace natural erosion needs to be
far higher.
Up to 30 feet of bluff erosion in certain locations was observed in the winter of
2012-2013. That erosion event was the impetus to approve the emergency project
and resulted in the installation of the existing geotube system. As stated above that
event, including the loss of 30’ in certain locations is included in our dataset used to
calculate the Coastal Bank erosion rate. Therefore, we have not undercounted the
unprotected Coastal Bank erosion rate.
e) Project is not performing as described. We were told that the 22 cy template
would all fall in through gravity.
That was never the design or how its operation was described. Given that the top of
the template is nearly level, sand cannot fall by gravity from the top of the template.
The design intent, and template management, always called for the face of the
template to be covered by sand and re-covered after erosion events. Sand from the
top of the template would be used to re-cover the exposed face. See OOC Special
Condition No. 32 which reads in part “…Throughout the winter, place additional
sand on an as-needed basis, in accordance with the replenishment trigger in the
Milone & MacBroom November 12, 2013 letter (i.e., if half the vertical height of the
lowest Geotube is exposed, place a minimum of 2 cy/If). …” This calls for the
placement of sand on the template face and there was no intent that sand would fall
by gravity off the top of the template onto the face of the template.
3. Performance During March 2018 Storms
a) The lack of sand cover for three storms in March 2018 deprived the littoral
system of needed sand.
The lack of sand cover did not deprive the littoral system of sand. As described
above and previously, the template was documented to contribute about 20 cy of
sand per lf of template during the 2017-2018 sand year. A thorough description of
events and sand placement during March 2018 was presented in detail in our
correspondence dated 07 February 2019.
As described in the 07 February 2019 correspondence, the volume of sand
contributed to the littoral system during the March 2018 storm period was about the
required minimum volume established in the OOC of 2 cy/lf. This does not mean
the SBPF is “metering out” only 2 cy of sand per linear foot, as suggested during the
Nantucket Conservation Commission 7
Re: DEP File No. SE 48-3115
March 1, 2019
11 February 2019 Public Hearing. Rather, it was presented to document that even
during a tough sequence of storms, when there was not time to re-cover the face of
the geotubes, the SBPF met the OOC minimum requirements by contributing
approximately the same amount of sand from the end ramps and major sand
delivery point at the southern end of the project, that would have been contributed
off the face of the geotubes.
b) Re-covering the geotubes in a timely manner is not feasible.
It is feasible to re-cover geotubes in a timely manner. Before the March 2018
sequence of storms SBPF was able to re-cover exposed geotubes after erosion events
in accordance with the OOC. March 2018 highlighted logistical constraints when
there were several back-to-back intense storms. The memo dated 06 February 2019
regarding Expanded Baxter Road and Sconset Bluff Storm Damage Prevention
Project (DEP File No. SE 48-3115) – Future Maintenance Procedures, describes
changes in procedures to re-cover geotubes in a timely even during intense storm
seasons.
4. Impact of timing of sand mitigation on littoral system
a) Failure to supply sand in real time during large storms after the sand that
covers the geotubes washes away and they are left exposed is the fatal flaw
depriving the littoral system of sand when it needs it the most.
This issue has been raised and answered repeatedly. The number of times that sand
has not been available because a series of storms occurred close together and the
geotubes have not been re-covered is small. In addition, it has been demonstrated
that the timing of the sand contribution is not a significant fact to effectively mitigate
for the prevention of natural erosion of the Coastal Bank as long as the long-term
sand contribution is met.
The Project is designed to meet the required performance standards for Coastal
Banks that are both a buffer to storm waters and a sediment source to down-drift
landforms. The geotube system and sand template was designed to accomplish
both of those functions.
The Expanded Project and Existing Project are both designed as geotube arrays
covered by sand so that the sand along the face of the geotube system will erode
during storms and contribute sand to the littoral system during storms. Mr. Berman
notes. “This is a good feature of the design as it provides sand to the littoral system
during storms, as during storms is when additional sediment in the nearshore would
Nantucket Conservation Commission 8
Re: DEP File No. SE 48-3115
March 1, 2019
have the biggest impact on preserving the upland and coastal resource areas.” [page
5] This design feature meets the standard to provide sediment to downdrift
landforms. The geotubes serve as a buffer to storm waves to protect the Coastal
Bank from further erosion, an interest of the Act and Bylaw, and the basic project
purpose for the Existing and Expanded Project.
Most projects approved by MassDEP are only required to provide the annual
average volume of mitigation sand once per year. The existing Project and the
proposed adaptive template management program is a significant upgrade from that
typical “best available measure” accepted for other projects in Massachusetts.
As described for issue 3. a) above, sand has covered the face of the geotubes for
nearly all storms. Occasionally it has not been possible to re-cover geotubes, and
that has happened only three or four times over five years, with two of those events
occurring last March. However, other sources of sand were available even when
the geotubes were not yet recovered e..g. from the sand ramps and delivery points.
For example in March 2018 about 5,500 cy of sand was contributed from the ramps
and southern delivery point. Further, as described in detail during the 05
November 2018 Public Hearing presentation on Sediment transport, the timing of
the contribution is less important than the volume contributed to the littoral system.
Because the littoral system is comprised of several zones in which sediment is
mobilized and transported, there is a time lag as sand migrates off of the Coastal
Bank, on to the Coastal Beach, then to the nearshore (swash and breaking wave
zones) where it is transported down-drift by long-shore transport. Whereas
adequate sand volume has been supplied, there has been no damage to down-drift
Coastal Beach since the existing geotube system was installed.
Furthermore, as Mr. Berman noted the majority of the sand in the system is provided
by up-drift sources, and as we described above for issue 1. e) above, the sand off the
template is mitigating for the placement of the geotube system in front of the Coastal
Bank and not resulting in a net loss of sand to the littoral drift system
b) Jim O’Connell comments from 2013 prove that the timing of the sand
contribution is critical.
Mr. O’Connell’s comments dated November 4, 2013 were submitted regarding the
existing Project (DEP File No. SE48-2610), and a response prepared by Milone and
MacBroom dated November 12, 2013 is available in the record . Mr. O’Connell’s
letter references a proposed design and mitigation protocols that differ from the
Expanded Project currently being reviewed by the Commission.
Nantucket Conservation Commission 9
Re: DEP File No. SE 48-3115
March 1, 2019
The work subject to that earlier filing about which Mr. O’Connnell commented, was
appealed and through the appeal process that design and mitigation protocol was
scrutinized by MassDEP. A separate comprehensive review also was conducted
pursuant to the Massachusetts Environmental Policy Act (“MEPA”) which is required
before MassDEP can issue a Superseding Order of Conditions (“SOC”).
Whereas as the issuing agencies issued an SOC (SE48-2610) and a subsequent OOC
(SE48-2824) was issued by the Commission, both with conditions to protect the
interest of the Act and Bylaw, the five year old comments by Mr. O’Connell appear
to have been adequately resolved to allow the SOC and OOC to be issued.
5. Compliance with Local Regulations
a) Homes eligible for protection – a Commissioner is concerned that four (4)
pre-78 Baxter homes did renovations that exceeded the limit in the local
regulation and therefore are not eligible for protection.
It was requested that all homes on the east side of Baxter Road be reviewed relative
to the Local Regulations regarding pre-1978 eligibility. That was provided to the
Commission in our correspondence dated 16 November 2018.
Review of the SBPF analysis and material provided by Commissioner Golding
identify only four (4) homes where there is disagreement over local eligibility – 83,
79, 77 and 73 Baxter Road. An assessment Building Department records shows that
for all four of these homes, the increased space did not exceed the 20% standard in
the Local Regulations. See the attached Memorandum dated 28 February 2019 that
reviews the eligibility of these four homes.
Upon further review of this matter, we note that the Town of Nantucket Bylaw for
Wetlands (Chapter 136) (“Bylaw”) was approved 19 August 1983, and the Town of
Nantucket Conservation Commission Wetland Protection Regulations (“Local
Regulations”) were first effective 25 February 1988. However, the more stringent
standard to define eligibility of homes that can be protected by a coastal engineering
structure pursuant to the Local Regulations Section 2.05 B.1 is retroactive to August
1978. How can the Local Regulations retroactively establish a more stringent
standard to a date some five (5) years before the Bylaw was effective, and some ten
(10) years before the Local Regulations were effective? The corresponding State
Regulation limiting which homes can be protected by a coastal engineering
structure is tied to the effective date of the Coastal Wetland Regulations, i.e. 10
August 1978, see 310 CMR 10.30(3).
Nantucket Conservation Commission 10
Re: DEP File No. SE 48-3115
March 1, 2019
b) The project must prove that has “no impact” not just that it is the “best
available measure.”
A detailed review of compliance with the relevant performance standards was
presented in our correspondence dated November 2, 2018; and a verbal review of
the relevant performance standards was made at the October 1, 2018 Public
Hearing.
The Nantucket Wetland Protection Regulations for Coastal Bank (Section 2.05) are
not as broad reaching as the commenter suggests. Section 2.05(3) reads: “All
projects shall be restricted to activity as determined by the Commission to have no
adverse effect on bank height, bank stability, wildlife habitat, vegetation, wetland
scenic view, or the use of a bank as a sediment source.” The no adverse applies to:
Bank Height – The proposed Project does not change bank height.
Bank Stability – The project purpose is to maintain, or protect, the stability of the
Coastal Bank seaward of Baxter Road. This achieved by installing the geotube
system and re-planting exposed Coastal Bank substrate.
Wildlife Habitat – Construction will be timed to avoid potential adverse effects on
bank swallows, prior to construction the applicant will conduct a bank swallow
survey and in locations of the nest cavities no planting will occur, and the applicant
concurs with the special conditions proposed by the NHESP in their letter date
February 11, 2018.
Vegetation – The majority of the Coastal Bank on which he stabilization system will
be built is un-vegetated. As described in the NOI and noted above, the exposed
bank substrate will be planted beach grass and other native vegetation on the bank
face to stabilize the exposed substrate and enhance vegetation in the Project area.
Wetland Scenic View – Geotextile tubes covered with sand and the slope re-planted
with vegetation will have wetland scenic views similar to bank appearance before it
was denuded by erosion.
Bank as a sediment source – The construction maintenance of a sand template
above the geotubes, and implementing the adaptive sand management program as
described in the Template Sand Protocol will maintain this reach of Coastal Bank as
sediment source.
Nantucket Conservation Commission 11
Re: DEP File No. SE 48-3115
March 1, 2019
6. Project as Temporary Project
a) SBPF requested protection for Baxter Road for 5 years as a temporary project
only. Now it is switching and asking to protect Baxter Road on a long-term
basis.
The notion that the Existing Project is a “temporary project” is not supported by the
record. It has been clear from the outset that to the extent the existing Project is
considered “temporary” because it will be replaced by a long-term project within 3-
6 years. That is exactly what is happening now and how the project has been
described in all official documents, notwithstanding the continued
misrepresentation of this subject from project opponents. The SOC issued by
MassDEP reads in part:
“The Geotube proposal has been represented to be a temporary project lasting for
approximately 3-6 years. The SBPF indicated that this timeframe will allow a long-
term protection project, such as a longer Geotube or rock revetment to be
identified, permitted and implemented. The Town of Nantucket also indicated that
it will take a similar amount of time to undertake actions necessary to relocate the
Baxter Road access to homes and the co-located water and wastewater infrastructure
serving those homes in order to mitigate the imminent threat to public health and
safety that warranted the issuance of the Emergency Certification. As a result, the
Department’s SOC approves the Geotubes as a temporary installation for a period of
up to 6 years.”
The OOC for the installation of the fourth tier of geotubes included Special
Condition No. 41 reads:
“Approval for the project is for three years, with the option to request a three-year
extension upon expiration of the initial three-year term. The applicant shall not
apply for a long term or long length expansion of the Project prior to January 1,
2018 and shall not begin construction of such until after September 1, 2018. The
Applicant may apply for localized alterations to the Project as may be appropriate
based on site conditions, and may apply for any alteration or expansion necessary to
address an emergency or imminent danger.”
Although these two statements use the term “temporary” and place a time limit on
the approved Project, the stated purpose was allow SBPF time to identify, design
and permit a long-term protection project. The significant monitoring of the existing
Project and prohibition to requesting a long-term or long length expansion until
Nantucket Conservation Commission 12
Re: DEP File No. SE 48-3115
March 1, 2019
January 2018 was to have three years of data on the possible effects of the initial
Project, consistent with a “demonstration” project.
Now with five years since the first installation and three years since the installation
of the fourth tier, monitoring has demonstrated no adverse effect on the downdrift
beaches, and the SBPF seeks to permit the originally intended length of the geotube
system.
b) Now that an alternative access plan for the northern end of Baxter Road is in
place, the erosion project can be removed and Baxter Road abandoned.
That idea that the geotube system now can be abandoned because the Baxter Road
relocation plan is prepared is a mis-reading of: the Memorandum of Understanding
(“MOU”) between the Town of Nantucket and the SBPF dated 05 July 2013, the
Amendment to the MOU dated 09 October 2013 (collectively referred to as the
“MOU”), and the Alternative Access Agreement (“AAA”). There is no requirement
to remove the geotube system now that the back-up relocation plans have been
prepared for the roadway.
The agreements make clear that the alternative access is to be available to the Town
only in the case that the geotube project fails for engineering or performance
reasons and that as a result Baxter Road must be closed. SBPF has discharged its
responsibility as stated in the MOU and AAA in conjunction with neighborhood
property owners and has provided the necessary land area and engineering plans to
the Town on the agreed-upon “back-up” basis. The Town’s responsibility in
accordance with the MOU and the AAA is to support SBPF in its efforts to carry out
the geotube project, including the Expanded Project as long as the project is
functioning in a manner consistent with the permitting authorities. A decision on
the part of the Town to withdraw from the MOU or AAA on a discretionary basis,
even though the project is in compliance with its permit, would eliminate the
Town’s ability to utilize the property being voluntarily provided at no cost to the
Town under the AAA.
The only mention of removing the geotubes relative to the relocation of Baxter Road
is OOC Special Condition No. 46, which is only triggered after the relocation of
Baxter Road. Special Condition No. 46 reads: “Upon relocation of Baxter Road the
applicant shall appear before the Commission to discuss if the Geotubes in front of
land not containing pre-1978 structures shall be removed and returns installed, in
keeping with those shown on the plan of record, on the remaining Geotube
structure. This shall take place within 90 days of the relocation of Baxter Road.”
Nantucket Conservation Commission 13
Re: DEP File No. SE 48-3115
March 1, 2019
7. Coastal Bank Cross-sections In North Reach of the Project Area
a) The Commission requested revised a plan depicting cross-section of the
northern end of the geotube extension Project Area.
See attached cross-sections of the northern portion of the Coastal Bank dated 21
February 2019. Review of this figure shows the slope is 1.3:1 to 1.4:1 (horizontal to
vertical) (35° to 38°angle) above the zone of toe scour that occurred between the
2017 and 2018 topographic surveys.
We cannot predict the natural angle of repose for this Coastal Bank, though a 38°
slope is likely approaching it. When the bluff is steeper than this, we observe bluff
retreat in some locations, especially where there is no vegetation on the face of the
bluff. Where there is vegetation, there are numerous examples of this on the un-
eroded bluff, where the slope is very steeper and remains relatively stable by well-
established vegetation. We can predict however, that continued toe scour will lead
to over-steepening of this Coastal Bank and erosion. Thus, there is a need for the
proposed Expanded Project to protect the pre-1978 homes at 115, 113 and 109
Baxter Road, the public infrastructure of Baxter Road, and utilities adjacent to the
road.
8. Sesachacha Pond and Environs
a) Expanded Project may increase risk of future breaches and affect the pond
(salinity and ecosystem).
The opening, or beach wash over, from the ocean to Sesachacha Pond is clearly
visible on aerial images available in Google Earth as far back as 1995. This opening
is approximately 7,000 linear feet (1.33 miles) north of the northern limit of the
Expanded Project. This opening is the between WHG profiles 98 and 99. Review
of the 77th Survey Report shows the shoreline in this location has experienced
periods of accretion and erosion during the 1994 – 2018 survey period. As has
been discussed previously (see the 05 November 2018 Public Hearing presentation
on sediment transport) sediment transport and shoreline movements are complex
mechanisms, and shoreline changes within the range of historical observations at a
portion of shoreline that is more than 1 mile away cannot be directly attributed to
the Project due to distance.
Nantucket Conservation Commission 14
Re: DEP File No. SE 48-3115
March 1, 2019
In closing, the SBPF and its consultants have submitted: an NOI for this long-length
extension to the existing geotube system (consistent with OOC SE48-2824 Special
Condition No. 41 and the SOC issued for SE48-2610); presented the Expanded
Project; responded to questions and comments at six Public Hearing sessions to
date; and have provided all materials requested by the Nantucket Conservation
Commission. Whereas we have:
presented the project design,
acknowledged potential adverse effects,
proposed a comprehensive plan to mitigate potential adverse effects, and
demonstrated compliance with the State and Local Regulations, and
performance standards,
we respectfully request that the Nantucket Conservation Commission issue an Order
of Conditions allowing the proposed Expanded Baxter Road and Sconset Bluff Storm
Damage Prevention Project to be built, and establish pragmatic Special Conditions
consistent with those issued for the existing Project (SE48-2824) to protect the
Interests of the Act and the By-law.
Sincerely,
EPSILON ASSOCIATES, INC.
Dwight R. Dunk, LPD, PWS, BCES
Principal
encl: Memorandum to the File, dated 28 February 2019
Typical Sections, dated 21 February 2019
cc: MassDEP-SERO
J. Posner, SBPF
A. Gasbarro, Nantucket Eng. & Survey
S. Cohen, Cohen & Cohen Law, PC
G. Wood, Ruben and Rudman, LLP
G. Thomson, W.F. Baird & Assoc.
L. Smith, Epsilon
R. Hamilton, Woods Hole Group
M E M O R A N D U M
Date: 28 February 2019
To: File
From: D. R. Dunk
Subject: Review of Local By-Law Eligibility (Lots 73, 77, 79, 83 Baxter Road)
The Siasconset Beach Preservation Fund (“SBPF”) previously provided a house-by-house evaluation
of all homes on the east side of Baxter Road relative to the Town of Nantucket Conservation
Commission Wetland Protection Regulations (“Local Regulations”) regarding pre-1978 eligibility.
That was provided to the Commission in our correspondence dated 16 November 2018.
Comparison of the SBPF analysis submitted in November and materials provided to the record by
Commissioner Golding identified only four (4) homes where there is disagreement over Local
Regulation eligibility; and those are 83, 79, 77 and 73 Baxter Road. Our review of Building
Department records for renovations to those homes since 1978 is presented below.
Recall that the Local Regulations define “Substantially Improved” as a cumulative expansion of
habitable space greater than twenty percent (20%); and “Habitable Space” is defined as, space in a
structure for living, sleeping, eating, or cooking. Bathrooms, toilet compartments, closets, halls,
storage or utility space, and similar areas are not considered habitable space.
Note that the Building Department information does not clearly track habitable space and therefore
some interpretation of this information is required.
83 Baxter Road
2001: Relocate one story 2,330 s.f. dwelling and place on a new foundation on the same lot. No
dimensional changes occurred – 0% change in habitable space.
1991: Addition to a one story 2,140 s.f. dwelling, Building Permit issued for a 200 s.f. sunroom
addition and replacement roof over dining room – 9.3% increase in floor area.
1982: Addition to a one story 2,041 s.f. dwelling. Building Permit issued for a 99 s.f. kitchen
extension – 4.9% increase in floor area. Structure dimension was determined to be 2,041
2
s.f. based on review of plot plans included in the 1982 and 1991 Building Permit files.
Note: There is confusion casused reviewing just application because the pre-permit square
footage is listed erroneously as 1,150 s.f on the 1982 application. Based on plot plans
included in the record and documents filed for subsequent permits issued for this property,
it is clear that this square footage entry was entered in error and should have been 2,041s.f.
to be consistent with the balance of the record.
Summary: Cumulative increase in habitable space from 1982 to 1991 was 299 s.f. divided by
original floor area of 2,041 s.f. correlates to 14.2% increase in floor area, assumed to be
habitable space. Therefore, this dwelling is eligible as a pre-1978 house because the
cumulative increase in habitable space is less than 20%.
79 Baxter Road
2013: Relocate single family house on the same lot. Building Permit reports dwelling contains
3,738 s.f. total floor area. No dimensional changes with building relocation – 0% change
in habitable area.
1999: Replace windows and redo roof walk. No dimensional changes – 0% change in habitable
area.
1997: Deck addition to dwelling. Building Permit issued for a 287 s.f. deck addition – 0% in
habitable area
1989: Alteration and addition to single family 3,272 s.f. dwelling. Building Permit issued for 466
s.f. net addition, use undefined – 14.2% increase in floor area. Pre-addition total floor area
was determined to be 3,272 s.f. as there are no other additions recorded in Building
Department files between 1989 and 2013.
Summary: Cumulative increase in habitable space from 1989 to 2013 was 466 s.f. divided by
original floor area of 3,272 s.f. correlates to 14.2% increase in floor area, assumed to be
habitable space. Therefore, this dwelling is eligible as a pre-1978 house because the
cumulative increase in habitable space is less than 20%.
3
77 Baxter Road
2006: Demolish 558 s.f. bunk house – 558 s.f. reduction in habitable space.
2005: Relocate single family house on same lot and add 555 s.f. addition per Certificate of
Appropriateness No. 47427 – 555 s.f increase inhabitable space.
Summary: Net change is a 3 s.f. reduction in floor area. Therefore, this dwelling is eligible as a
pre-1978 house because the cumulative increase in habitable space is less than 20%.
73 Baxter Road
2012: Relocate single family dwelling on same lot. Demolish 350 sf of 1st floor, add 150 sf to first
floor for kitchen, renovate baths, reside, and re-roof. Net change is a 200 s.f. reduction in
floor area.
1989: Construct a 10 ft x 14 ft (140 s.f.) addition to garage for storage – 0% increase in habitable
space.
1989: Construct 253 s.f. addition for library.
1986: Addition of 2nd story bathroom no area provided. Bathroom is not considered habitable
space – 0% increase in habitable space.
Summary: No total square foot of floor area could be affirmed from the records. Review of the
1989 permit application suggests the principle structure had a floor area of 1,534 s.f.
Records show that between 1989 and 2013 there was a net increase 53 sf in habitable
space. This correlates to approximately a 3.5% increase in floor area. Therefore, this
dwelling is eligible as a pre-1978 house because the cumulative increase in habitable
space is less than 20%.
Conclusion:
All four homes have had relatively modest renovations, and our review of Building Department
records show that these renovations do not exceed the 20% threshold established in the Local
Regulations.
-25
02550
-25
02550 0255075 -250255075100
REVISIONSREV(T.I.)T.I.TYPE OFISSUEDESCRIPTIONDRN DSN APR YYYY-MM-DDREV.PREPARED FOR:2/21/2019 10:18:29 PMDate Plotted:D:\PROJECTS\12643.101 SCONSET BEACH PRESERVATION FUND\H - CADD\WORKING DRAWINGS\C PERMIT\12643-C-RESPONSE TO QUESTIONS.DWG
DRAWING NUMBER:DATE:PREPARED BY:W.F. Baird & Associates Ltd.(A) INFORMATION(B) REVIEW(D) TENDER DOCUMENT(F) RECORD(E) CONSTRUCTION DOCUMENT(C) PERMITSCONSET BEACH PRESERVATION FUNDTYPICAL SECTIONS12643A010 A 2019-02-21A AFOR INFORMATIONBKC GGT GGT 2019-02-21GRAPHIC SCALE FEET0804020BTYPICAL GEOTUBE SECTIONGENERAL NOTES1.ELEVATIONS ARE REFERENCED TO MLW '92.2017 SURVEY100 YR STORM W.L (+7.68)2018 SURVEYFOR PERMITTING PURPOSES ONLY100 YR STORM W.L (+7.68)2017 SURVEY2018 SURVEYBATYPICAL GEOTUBE SECTIONAGRAPHIC SCALE FEET01000500250NORTH1.4311.301