Download PROJECT - Barnstable County

PROJECT
Town of Yarmouth, Comprehensive Wastewater
Management Plan, Draft September 2010
Expanded Environmental Notification Form
(EOEEA # 14659)
SUBCOMMITTEE
COMMISSION STAFF
Tom Cambareri, Scott Michaud, Heather McElroy, Sarah Korjeff,
Ryan Christenberry, Andrea Adams, Kristy Senatori
DATE
October 27, 2010
The Cape Cod Commission (Commission) has received a Draft Comprehensive Wastewater
Management Plan (CWMP), Expanded Environmental Notification Form (ExENF), (EOEEA
14659) for the Town of Yarmouth. The CWMP/ExENF was noticed in the Environmental
Monitor on September ##, 2010. The CWMP meets a number of categorical thresholds
according to the Massachusetts Environmental Policy Act (MEPA) that require a mandatory
Environmental Impact Report for the project. The Town of Yarmouth has sought a joint MEPA/
Cape Cod Commission review of the CWMP/ExENF. The Joint MEPA/Commission Public
Hearing is scheduled for November 3, 2010 and the close of comments to MEPA is November 3,
2010. Staff has reviewed the CWMP/ExENF and offers the following comments on the
Expanded ENF and the MEPA scope for the next step of the process.
Background on Yarmouth Comprehensive Wastewater Management Plan
Yarmouth Comprehensive Wastewater Management Plan /ExENF EOEEA 14659
October 20, 2010
Draft Staff Report
The CWMP/ExENF provides a strategy for wastewater management to achieve reductions of
nitrogen loading to restore and protect Yarmouth’s marine embayments. The CWMP/ExENF
also addresses; areas with septic system problems associated with density, soils, high
groundwater, drinking water, and planning significance.
The CWMP/ExENF proposes a Core wastewater facility and sewer collection system to serve
67% of the town to meet the nitrogen management, water quality and public health needs of the
town. The project would be implemented in five phases over a 25 year period of
implementation.
The Phased Sewer Plan also accommodates septage and sludge handling. The Phased Plan also
targets nutrient reduction through certain non-structural elements including enhancement of
embayment flushing rates.
The 2010 estimated cost of the CWMP is $260 million dollars over the 20 year implementation
period. The CWMP contains several cost allocation scenarios including 0 to 50% paid through
general tax and betterments ranging from 50 to 118% resulting in annual payments of $509 to
$1,416 and /or a combination of annual taxes from 0 to $466. The exact cost allocation model
will be determined prior to a scheduled Spring Town Meeting to approve the initial Phase 1 cost
of the CWMP at $55 Million dollars.
PROJECT DESCRIPTION
Yarmouth’s CWMP/ExENF articulates the town’s wastewater needs and proposes a Phased Plan
to address those needs. Wastewater management planning has been underway in Yarmouth
since 2003. Commission Water Resources staff have provided modest direct technical assistance
through the oversight of grants and the USGS groundwater modeling project through the
County’s former Wastewater Implementation Committee and input on the Route 28 Growth
Incentive Zone and other planning activities as they relate to wastewater.
The CWMP/ExENF proposes a five-phase wastewater management plan that will collect and
treat up to an annual average wastewater flow of 2.15 MGD from 9580 properties, which is 67%
of the total Yarmouth parcels to meet nutrient Total Maximum Daily Loads (TMDLs) for: Lewis
Bay and Parkers River. A significant portion of the properties served and estimated treatment
capacity also addresses high density residential development, Title 5 septic issues with poor
soils, high groundwater, drinking water protection and economic development along Route 28.
The wastewater flow analysis reported in the CWMP indicates a 21% increase in flow at
buildout conditions.
NATURAL RESOURCES
Heather
HISTORIC AND ARCHAEOLOGICAL RESOURCES
Sarah
Yarmouth Comprehensive Wastewater Management Plan /ExENF EOEEA 14659
October 20, 2009
Draft Staff Report
2
MARINE WATER QUALITY
Yarmouth has been participating in the Massachusetts Estuary Project (MEP) since it began in
2002. This included water quality sampling of its coastal waters in coordination with the Lewis
Bay Research Center and the Town of Barnstable and Town of Dennis. The MEP has provided
Technical Documents for Lewis Bay and recently released a Final Technical Document to the
Town on Parkers River. The Technical Document for Bass River has not yet been completed.
The Department of Environmental Protection (DEP) has recently released a draft Total
Maximum Daily Load for Lewis Bay which ended its comment period on October 30, 2010.
Although the Final Parkers River Technical Report is not publicly available, the town has
allowed Commission staff access to their digital copy within this review period for the purposes
of Commission review.
LEWIS BAY
The Lewis Bay embayment and watershed is shared with Barnstable. The MEP results indicted
on the Table below indicate that of the septic system source of nitrogen loading, approximately
40% must be removed. However, that amount is offset by subwatersheds in Barnstable that are
tributary to Hyannis Harbor which actually can receive more nitrogen than present. When only
the Lewis Bay proper watersheds are evaluated then nearly 80% of the septic source on nitrogen
must be removed. The percent removal already incorporates that portion of the Hyannis
watershed which is presently sewered, accounting for approximately 20% of the watershed
parcels.
LEWIS BAY
Town
B/Y
Y
Y
B/Y
B
B
embayment
Lewis Bay
Uncle Roberts Cove
Mill Creek
Hyannis Inner Harbor
Snows Creek
Stewarts Creek
Y
Y/B
Y
Chase Brook
Mill Pond
Hospital Creek
TOTAL
Existing
Load
Kg/day
26.49
0.214
13.57
6.847
7.97
21.564
Percent
Septic
Removal
-80
0.0
-85.6
-73.6
14
12.1
2.4788
10.425
1.907
91.475
-0.3
-3.4
-82.9
-39.45
ALTERNATIVE D
Scenario
Percent
D Load
Septic
Kg/d
Removal
0.351
-98.7
0.214
0.0
1.614
-88.1
4.723
-31
7.97
0.0
21.564
0.0
1.077
9.427
0.326
47.27
-57.7
-9.6
-82.9
-52
Yarmouth and Barnstable collaborated on developing a number of wastewater planning scenarios
for Lewis Bay. The scenarios included using the Barnstable WPCF as the treatment facility for
the Yarmouth portion, discharging the treated Yarmouth portion at the Hyannis facility and a site
adjacent to the Hospital cranberry bogs. Another scenario included keeping everything static in
Yarmouth Comprehensive Wastewater Management Plan /ExENF EOEEA 14659
October 20, 2009
Draft Staff Report
3
Barnstable and discharging the collected wastewater from Yarmouth out of the Lewis Bay
watershed.
Yarmouth Comprehensive Wastewater Management Plan /ExENF EOEEA 14659
October 20, 2009
Draft Staff Report
4
The initial sewering scenarios, A, B and C for Yarmouth which included the sewering of a
smaller portion of the watershed than shown above did not achieve the reduction necessary to
meet the TMDLs. The alternative scenarios D, E and F that included sewering a significant
portion of the Yarmouth watershed did meet the required TMDL for the existing conditions, but
under buildout conditions, the scenarios were just over the TMDL threshold. The scenarios did
not include additional sewering in Hyannis which is planned under the Barnstable Wastewater
facility plan. If this additional septic flow is collected and treated, the CWMP anticipates that
the TMDL would be achieved for the Watershed.
It is recommended that these regional scenarios for Lewis Bay be conducted. Since the scenarios
involve the ultimate use of the Barnstable WPCF which itself is a source of recycled nitrogen,
they are fairly complex. The future sewering scenarios will require that the additional nitrogen
load from newly treated septic sources are incorporated into the model. The MEP model
currently has groundwater flow conditions for incorporating existing flows at 1.7 MGD and
future flows at 2.95 MGD at the WPCF. The future buildout scenarios would have to use
capacity flow at the plant of 4.2 MGD that would incorporate septic flows from both the Lewis
Bay Watershed and outside of the watershed from the Wequaquet Lake and Centerville River
watersheds.
In addition, as the effluent discharge at the WPCF increases, the additional
wellfields and embayment systems in Barnstable will receive nitrogen from the new capacity.
New regulations with requirements for discharge in a Zone II were not in play during the 2007
review and its application to Barnstable will need to be evaluated. Commission staff have
offered to assist the Town of Barnstable in the development of these scenarios as part of the
Town’s Nutrient Management Plan/CWMP.
The Yarmouth CWMP advances its plan based on the results of Scenario D, which is the out-ofwatershed discharge option. The nitrogen loads and percent reductions are shown in the table
above. The sewer scenario has high percentage removal of 99% for Lewis Bay, 88% for Mill
Pond and 83% for Mill Pond. Lower amounts of nitrogen removal are achieved for Hyannis
Inner Harbor because it is shared with Barnstable and is serviced by the WPCF, and Mill Pond
and Chase Brook because they are further upgradient in the watershed and a larger percent of the
nitrogen load is reduced by natural attenuation. The out-of-watershed alternative is consistent
with the CWMP’s selection of a primary effluent recharge site located in the Parkers River
watershed Yarmouth.
PARKERS RIVER
The Parkers River and its watershed are entirely located in the Town of Yarmouth. It contains
the upper and lower Parkers River, Seine Pond aka Swan Pond, and Lewis Pond. Plashes Brook
is a tributary to Seine Pond that receives flow from Long Pond. Long Pond sits between the
Parkers River and Bass River watershed, therefore a portion of Long Pond watershed flows into
Forest Road Brook of the Parkers River watershed while another portion flows into the Bass
River Watershed. The Parkers River waters are listed on the 303d list of impaired waters and the
Final Technical MEP report was released to the town in May 2010. As of October 24, 2010 it is
not up on the Estuaries Website for public access. The Commission staff recently obtained
Yarmouth Comprehensive Wastewater Management Plan /ExENF EOEEA 14659
October 20, 2009
Draft Staff Report
5
digital access to the report from the town for the purposes of this review and therefore has not
previously reviewed or commented on the Technical Report. The Technical report has not been
incorporated into a draft TMDL.
The MEP report established the nitrogen threshold and developed a scenario to determine the
amount of nitrogen removal required to achieve the nitrogen threshold. The amount of nitrogen
to achieve the threshold is high; over 96% of the septic sources. However, the Parkers River has
a significant tidal restriction at the Route 28 crossing. Because nitrogen sensitivity is directly
related to specific tidal flushing, the Town of Yarmouth requested several MEP scenarios to
evaluate how the nitrogen sensitivity of Parkers River would be affected by changing or
improving the tidal flow at the Route 28 location. The MEP Technical staff prepared several
hydrodynamic models to determine flushing. The optimal scenario included widening the
restriction to a 30ft culvert which would result in better flushing and somewhat higher surface
water flows during high and storm tides. The Town and MEP also evaluated the potential
environmental impacts of increasing the tidal flow on nearby resources including homes and
septic systems and found them to be acceptable. An ENF and NOI will be filed by the Town
when the bridge project goes forward. The culvert redesign is anticipated during Phase 2 of the
sewer expansion plan. When the optimal culvert design is incorporated into the MEP model, it
indicates that only 66% of the septic load needs to be reduced as shown in the Table below.
PARKERS RIVER
Embayment
Seine Pond
Upper Parkers
River
Lower Parkers
River
Lewis Pond
TOTAL
Threshold Alternatives
Culvert
Percent
Load
Septic
Kg/day
Removal
7.65
-59
Existing Load
Kg/day
18.649
Threshold
Load
Kg/day
51
Percent
Septic
Removal
-97
16.022
0.37
-97
4.32
11.751
14.746
61.168
0.59
0.73
2.2
-95
-95
-96.1
14.11
4.4
20.48
BO-4
Load
Kg/d
Na
Percent
Removal
BO-4
Na
-73
Na
Na
-65
-70
-66.5
Na
Na
21.89
Na
Na
-64.2
FRESHWATER PONDS
According to the Cape Cod Pond and Lake Atlas, there are 70 fresh water ponds in Yarmouth ,
of which 10 are Great Ponds greater than 10 acres. The Yarmouth CWMP does not include a
systematic assessment of these ponds so the potential impact of phosphorous from septic systems
and runoff is not known. However, the CWMP incorporates the freshwater pond findings
contained in the MEP Technical Reports. Fresh water ponds are important components of the
watersheds, MEP finds that these ponds attenuate nitrogen that flows through them according to
groundwater flow. In general the MEP finds that the ponds attenuate 50% of the nitrogen and
this general factor has been incorporated for Plashes, Big Sandy and Bassetts Lot Pond in the
Parkers River watershed.
Yarmouth Comprehensive Wastewater Management Plan /ExENF EOEEA 14659
October 20, 2009
Draft Staff Report
6
Long Pond is the only pond in Yarmouth with enough water quality data and bathymetry to
estimate a specific attenuation rate. The initial estimates are that Long Pond can attenuate up to
89% of the nitrogen. The flow dynamic between Long Pond through Forest Brook to Seine Pond
was a matter of some study in the MEP Parkers River Report. Initial estimates indicated that
40% of the water from the watershed of Long Pond would be diverted through surface water
flow via Forest Brook to Parker River. The remainder of the water would flow as groundwater
into the Bass River Watershed. During the course of the MEP report, the surface water flow
from Long Pond was improved for herring management. As a consequence of the alterations the
MEP estimated that the flow increased 6 times. However, even with the increased flow only
slightly more than 40% of the Long Pond Watershed flow and attenuated loads now discharge
into the Parker River Watershed (pg49-MEP). The MEP indicates that the nitrogen attenuation
rate for Long Pond after the alteration is 67% of the nitrogen load from the watershed. The flow
changes were made in the buildout scenarios in which case it appears that the overall load from
Seine Pond did not change appreciably from the buildout conditions prior to the incorporation of
the new flow to after the flow improvement, from 8829 to 8755 kg/y respectively.
DRINKING WATER
There are 24 groundwater public supply wells that provide approximately 4.04 million gallons
per day at an average annual and 6.5 million gallons per day at summer seasonal demand. The
Town has been aggressive about protecting its water supplies. The Town has substantial acreage
to protect water quality. Furthermore the Town fully assessed its supplies and threats in 1988
and as a result adopted strict Board of Health regulations to protect them from nitrogen loading.
In fact a solute transport model to calibrate nitrogen loading factors that would later be used in
the MEP method was applied to Yarmouth’s Well 4 and 5 that even at that time were impacted
by nitrogen loading septic systems in the upgradient Captain Village Area .
The Yarmouth CWMP includes a nitrogen loading assessment of the Zone IIs to all of the public
supply wells. The method is similar to the MEP nitrogen loading component, but using some
more conservative factors from the Town of Yarmouth Health Regulation. The results of the
assessment identified the supply wells 4 and 5 as a current groundwater concern because the
average nitrogen concentration is 3.95 ppm with a single maximum high of 8.5 ppm and the
loading analysis predicts a concentration of 9.62 ppm and 9.79 ppm at build out. The fact that
these two predictions are similar indicates that the Zone is fairly well built out already. We
concur that this Zone II has been impacted by development as water quality could be improved
by sewering this area. The priority of this action should take into consideration that nitrogen
concentrations have been fairly stable since the 1988 report, approximately 4 ppm and the
percent of water pumped from these wells is 8% of the total amount pumped by the Town. The
Zone II containing Wells 10 and 11 are also identified as impacted and needing restoration in the
full analysis contained in Appendix J2. The fortunate outcome of the CWMP analysis is that all
of the other wells nitrogen concentrations are below 2 ppm supporting the fact that the Town has
protected them well by committing approximately 1/3 of its area to wellhead protection.
Yarmouth Comprehensive Wastewater Management Plan /ExENF EOEEA 14659
October 20, 2009
Draft Staff Report
7
FACILITY SITING AND EFFLUENT DISCHARGE
The identification of suitable wastewater and effluent recharge facility sites is one of the biggest
environmental and social challenges for a successful CWMP. The Yarmouth CWMP appears to
have successfully screened available sites to target a likely location.
The Town initially screened 116 parcels, 41 sites were retained after a secondary screening.
These sites were ranked and found that 15 were suitable for effluent discharge. Of these eight
sites were selected for further consideration. The town then estimated the potential recharge rate
that could be applied to the sites given aerial site constraints using conventional application rates
or either open or subsurface technology.
Commission Water Resources staff assisted the town in an initial analysis of the hydrologic
review of the eight potential sites through the $300,000 Barnstable County funded USGS
Regional Groundwater Modeling study in 2005. The CWMP reports that the town requested
three scenarios, two decentralized and one centralized. Through the use of the USGS regional
model, estimates of groundwater mounding and the trajectory of treated effluent through the
aquifer were provided. Based on the modeling results the town focused on two sites for testing,
R1 which is the existing Buck Island spray irrigation site for Yarmouth’s septage treatment
facility and R3, which is the town DPW yard. Given constraints at the DPW yard for future use,
R1 was put forward in the CWMP as the preferred centralized recharge site. A fourth USGS
modeling scenario was requested that used a larger recharge volume of 4.9 MGD which is the
hypothetical calculated engineering rate that can be applied to the available area of the site. In
comparison to the initial modeling scenario of 1.64 MGD, the increased rate results in much
higher groundwater mounding 7 to 8 feet and a larger trajectory arc of the spread of
contaminants indicating that the site cannot accommodate this high of an application rate.
The CWMP estimates costs of construction on a per acre basis using 1 gpd/ft2 for both open and
subsurface recharge and because they were similar arrives at a general cost of $220,000. The
CWMP also determined unit recharge rates of approximately 35,000 gpd/acre for open bed
application, and 24,000 gpd/acre for subsurface infiltration assuming 1 gpd/ft2 rate. The CWMP
presents an evaluation of 3 options, two that spilt recharge flows between open and subsurface
beds and one that used only open beds at a combination of the three identified sites. The CWMP
concludes that the R1 site is the preferred central site because it is in the Parker River watershed,
is the lowest cost and considered most appropriate since it already is used for effluent recharge
from the septage treatment plant.
The CWMP acknowledges that the ability of the Parkers River watershed to handle additional
flow must be furthered explored and that the hydrologic model needs to be refined with updated
data. The 2005 modeling was only conducted at 1.65 MGD while the CWMP is projecting 2.75
MGD at build out. The estimate of water table mounding from the regional model should be
refined with a more site specific determination. In other CWMPs that the Commission has
reviewed, detailed hydrogeologic information is used to refine the mounding and trajectory
determinations. In addition, the existing estimates of water table elevation need to be
supplemented with actual site measurements and groundwater flow information as well as
Yarmouth Comprehensive Wastewater Management Plan /ExENF EOEEA 14659
October 20, 2009
Draft Staff Report
8
estimate of historic and projected high groundwater for the off season and peak season flow
rates. A double ring infiltrometer was used to evaluate infiltration rates, whereas more
substantial longer term testing methods are recommended for a centralized facility. Although
much of this information is required through the groundwater discharge permit process,
Commission staff recommends that the hydrogeologic assessment should be completed prior to
finalizing the EIR process to better substantiate the characteristics and capacity of the site.
The CWMP proposes a Sequencing Batch Reactor SBR as the preferred treatment system. The
CWMP also indicates that the SBR system will be built to later accommodate a MBR for higher
treatment, if necessary. The treatment system will initially be built to accommodate the
wastewater flow from Phase 1 and 2.
The preliminary site characterization indicates that that the full buildout flow of 2.65 MGD
cannot be accommodated at site R1, so another site(s) will be necessary to accommodate the
future flow. The CWMP suggests either R6 or R2 as alternative sites that could be used for the
buildout flow plus potential flows from the Bass River watershed that is shared with Dennis.
Another site that should remain up for consideration is the R8, Hospital Bog site, which could be
considered a potential regional site. The Hospital Bog site was evaluated by the Town of
Barnstable through the USGS modeling project. The concept behind this site was to: 1) use the
natural attenuation of the Bogs, 2) provide hydrologic balance to the water withdrawals of the
Maher Well field and 3) make use of a discharge site that is not in a Zone II. The analysis
indicated some potential use and MEP scenario F indicated that the Lewis Bay TMDL could be
met for existing conditions. The CWMP analysis of site capacity was held to lower conventional
application rates for a site in which flow to the abandon bogs would be by design.
WASTEWATER NEEDS AND COLLECTION
The Yarmouth CWMP evaluated a number of parameters for determining sewer needs. These
included: high density development, soils, and problem areas with high groundwater, drinking
water, planning significance and water quality. Each of the parameters were ranked and scored.
The CWMP recognizes high density development, of ¼ acre, as one of the primary wastewater
need components. The MEP results are added to the wastewater needs.
The CMWP acknowledges that the decision to use one or multiple sites is multi-faceted and that
the issue of balancing the wastewater (nitrogen) needed to be removed is best accomplished by
taking it totally out of the watershed. The primary recharge site recommended by the Yarmouth
CWMP is in the Parker River nitrogen sensitive watershed. The CWMP accommodates the
transfer of flow to the Parkers River watershed by providing additional treatment.
The Town requested another set of MEP scenarios to be run that would evaluate the ability to
transfer wastewater from other watershed into the Parkers River watershed. This is referred to as
scenario BO-4 for which is described in the MEP Technical Report. By providing offsetting
wastewater collection in the Parkers River and extra treatment to 3 ppm, the MEP found that the
Yarmouth Comprehensive Wastewater Management Plan /ExENF EOEEA 14659
October 20, 2009
Draft Staff Report
9
Parkers River nitrogen threshold could “nearly achieve the required threshold concentrations, but
would require some additional watershed load to be removed to reach the needed level of
restoration” despite the transfer of out-of watershed flows. The flows for this “buildout”
scenario are actually more closely aligned with the existing flows. This scenario defines the
upper limit and combination of in-watershed and out-of-watershed flows to 1.19 to 0.74 MGD
respectively. The decrease in attenuated total loads for the BO-4 scenario is 42%. The
Technical Report did not include specific septic load reductions for comparison. Because the
proposed plan is just above the threshold for Lewis Pond in the Parkers River, the CWMP needs
to more specifically propose how the TMDL level for Lewis Pond can be attained. As another
factor to reduce overall load from the proposed treatment site, the CWMP also proposes the
piloting of a Passive Reactive Barrier at the site of the facility. It is not known how effective the
PRB would be to treat a very well treated effluent. Discussion with the technology leaders
indicate that PRB treatment is better geared toward a composite groundwater waste stream
containing both nitrogen and higher levels of organic matter. The objectives of the PRB pilot
project can be specified in the Adaptive Management Plan.
Yarmouth Comprehensive Wastewater Management Plan /ExENF EOEEA 14659
October 20, 2009
Draft Staff Report
10
Wastewater Flow Transfers Between
Watersheds
Embayment
Parkers River
Lewis Bay
Nantucket Sound
Bass River
Total Flows
Existing
MGD
0.983
0.611
0.198
0.154
1.946
Buildout
MGD
1.19
0.74
0.239
0.186
2.355
If accommodating additional flows at the R1 Buck Island site in Parkers River watershed at
buildout is problematic, the transfer of wastewater and nitrogen load from the Zone II area north
of Long Pond should be re-considered. Nitrogen from this watershed is presently attenuated up
to 67% by Long Pond. Only slightly more than 40% of the flow from the watershed is routed,
primarily as surface water, to Parkers River. The other 60% of water underflows as Long Pond
as groundwater and discharges into Bass River. Therefore only 25% of the nitrogen load from
the Long Pond watershed is contributed to Parkers River. However, the CWMP ranks this area
high as a wastewater needs area for other reasons, drinking water protection, as previously
discussed, high groundwater problems and high density and soils. Because this is a Phase 4
sewer area, the need to sewer can be further considered with the fact that the wells capture water
from a smaller Zone of Contribution within the Watershed zone, the wells account for 8% of the
total water pumped, the nitrogen concentrations from the wells have been stable since the late
1980s and that the nitrogen load in the watershed is attenuated by nearly 75%. In addition, the
area could be considered for an alternative Bass River recharge site within the Adaptive
Management Plan.
The Nantucket Sound watershed is identified as a needs area for high density, high groundwater
problems, economic development and water quality. Staff did not see justification within the
CWMP that indicates that the Nantucket Sound watershed has an MEP identified water quality
problem. The CWMP in one instance scores the Nantucket Sound watershed at a higher need
due to water quality but then provides a contrary summary point when it states that “there are no
nitrogen limits for this area.”
ALTERNATIVES ASSESSMENT
The Yarmouth CMWP recommends the back bone of a town system served by one treatment
facility in its initial years, but reserves judgment on how many potential recharge sites might be
necessary depending on the outcome of the Bass River report and ultimate capacity of the R1
Buck Island site in the Parkers River Watershed. The CWMP includes several alternative
assessments. The alternatives analysis include a decentralized plan with two facilities and 3
recharge sites, and another plan with five treatment locations with five sites. Alternative
Yarmouth Comprehensive Wastewater Management Plan /ExENF EOEEA 14659
October 20, 2009
Draft Staff Report
11
Innovative systems assessment was based on 2004 data from the septic system test center. We
also note that the Town of Yarmouth conducted a study of treatment facilities technology that
was funded by Barnstable County that was not considered in the Plan. The alternative cost
assessments are based on cost of the different infrastructure to attain the preferred plan’s 25 year
end-point. The decentralized alternative was found to cost 59% more than the centralized plan.
The CWMP provides an excellent case by case determination about which types of wastewater
collection technology would provide the best outcome for Yarmouth. The CWMP proposes a
combination of vacuum, gravity, force mains and low pressure collection systems for the
identified wastewater needs areas of Yarmouth.
REGIONAL WASTEWATER MANAGEMENT
The Yarmouth CWMP evaluated regional opportunities for wastewater infrastructure on several
levels. The Town collaborated with Barnstable to have MEP scenarios provided for Lewis Bay.
These scenarios provided enough information that indicates the Town of Yarmouth has a
responsibility to provide significant nitrogen reductions. The Town of Yarmouth also
collaborated on an assessment to convey and treat the Yarmouth portions of wastewater from
Lewis Bay at the Barnstable Wastewater Treatment. The assessment provided details on the
complex issues involved with regionalizing the existing treatment facility. The discharge
capacity at the plant is limited and Barnstable has reserved that allocation to future sewer
expansions. Therefore, the assessment included Yarmouth wastewater conveyed to the WPCF,
with the treated effluent returned to Yarmouth. Conveyances for force mains and return effluent
mains were included in the assessment. The conclusion of the assessment was that the regional
option would cost Yarmouth nearly $13 Million dollars more than if it provided its own
treatment. Barnstable is in the midst of its Nutrient Management Plan that may re-evaluate the
allocations of the existing Facility Plan. If the new Plan finds the need to provide additional
collection in the Lewis Bay watershed, then the parameters of the regional scenario and cost
estimate may change in the future. It is noted that the sewering of the Yarmouth portion of the
Lewis Bay Watershed is Phase 3 which is scheduled in years 10-15 that will allow time to reevaluate this potential regional opportunity. Other areas of regional sharing could be expanding
the Barnstable Willow Street AOC to include some of the dense residential development in the
Mill Pond Watershed in Yarmouth
ADAPTIVE MANAGEMENT PLAN and TMDL COMPLIANCE
The CWMP/Ex-ENF discusses an Adaptive Management Plan (AMP). The Commission will
require a detailed Adaptive Management Plan to be developed that fits the five-Phased Sewer
Approach. The AMP allows a systematic and prescribed process to report on the town’s
activities and to incorporate new technical information and potential agreements among the
towns in the shared watersheds. This information will aid the local and regional decision making
process for the plan’s later phases. The AMP should be informed by regular monitoring of water
quality in the embayments and reductions of nitrogen load in the watersheds to evaluate TMDL
compliance. Annual progress on all these matters is to be reported to both DEP and the Cape
Cod Commission.
Yarmouth Comprehensive Wastewater Management Plan /ExENF EOEEA 14659
October 20, 2009
Draft Staff Report
12
Because the length of CWMP implementation is several decades, a supplemental analysis could
include an assessment of length of time to achieve the TMDL goals. This would require an
assessment of load by phase by watershed. Unfortunately the watershed data is not easily reconfigured to perform that type of study. Therefore it is appropriate to prioritize phases that will
most expedite the reduction of nitrogen loading in those impacted watersheds and to track them
via adaptive management reporting.
To gauge the progression and set comparative milestones for TMDL compliance for the
embayments, Commission Water Resources staff recommends that assessments should be
conducted that will integrate the progression of planned sewering in the collective shared
watershed with MEP scenarios to project the progress of improved water quality. This
assessment should be done independent of the FEIR timeframe, but inform decisions about
CWMP phased implementation.
LAND USE
The Yarmouth CWMP did not under take an independent assessment of buildout of growth. The
CWMP relied upon the MEP buildout analysis to predict future wastewater flows. The MEP
studies however are only watershed specific. For instance, the Parkers River watershed indicated
that buildout would be 5 % if only residential growth was expected, but that the load would be
47% higher if potential commercial growth is anticipated. The data from the MEP reports
generally indicate that Yarmouth is a fairly well buildout community already and suggests a 16%
buildout, which we assume is for the entire CWMP planning area. The Town indicated that an
additional 5% should be added to accommodate commercial growth so that the buildout is 21%.
However, potential new growth from economic development along the Route 28 Growth
Incentive Zone has yet to be evaluated. Having better predictions of growth with a timeline of
achieving buildout could provide better predictions of interim flows so that treatment capacity
can be tailored to the site and not be over built.
The CWMP indicates that the Town desires the sewering of existing residential areas to be
growth neutral and that the Town plans to implement residential growth controls to a reasonable
yet not too restrictive level. The ultimate goal is to achieve a growth neutral scenario that is
consistent with the buildout condition of the CMWP. That buildout condition will need to be
better defined if the Town wishes to pursue 0% SRF funding through the O’Leary Bill.
ENERGY RESOURCES
Ryan
CONCLUSION
In conclusion, Commission staff believes the Expanded ENF for Yarmouth CWMP is
sufficiently detailed to be considered a Draft EIR. The schedule of the CWMP calls for moving
the project to town meeting approval in the spring of 2011. As such, staff recommends that the
town be permitted to proceed to the preparation of a Supplemental Draft CWMP/EIR.
Yarmouth Comprehensive Wastewater Management Plan /ExENF EOEEA 14659
October 20, 2009
Draft Staff Report
13
Yarmouth Comprehensive Wastewater Management Plan /ExENF EOEEA 14659
October 20, 2010
Draft Staff Report
Yarmouth Comprehensive Wastewater Management Plan /ExENF EOEEA 14659
October 20, 2009
Draft Staff Report
15
Yarmouth Comprehensive Wastewater Management Plan /ExENF EOEEA 14659
October 20, 2009
Draft Staff Report
16
Yarmouth Comprehensive Wastewater Management Plan /ExENF EOEEA 14659
October 20, 2010
Draft Staff Report