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HomeMy Public PortalAboutWater Resources Summary Paper1 | P a g e BREWSTER VISION PLANNING COMMITTEE SUMMARY PAPER WATER RESOURCES July 2022 I. BACKGROUND Brewster residents value the Town’s water resources and recognize that they are an integral part of the community’s character. In the 2017 Brewster Vision workshops, residents especially identified Brewster’s freshwater ponds as important assets to the Town for their aesthetic and recreational values. Residents also recognized the importance of clean drinking water and the relationships between protecting open space and preserving water quality throughout the Town. Over the last 40 years, the Town has made a concerted effort to protect groundwater quality. The Town has purchased significant areas of open space to protect the Town’s ponds and drinking water, particularly in the zones of contribution to its six municipal wells. The Town has also developed land use management policies and regulations to prevent development activities from harming water resources. In particular, in 2008 the Brewster Water Protection District of Critical Planning Concern was designated by the Cape Cod Commission for the Town’s Zone IIs- the area from which town wells potentially draw groundwater and the Town’s portion of the Pleasant Bay watershed. This resulted in the development of new water quality performance standards that were incorporated into the Town’s Water Quality Review Bylaw. In 2015, the Town completed an Integrated Water Resource Management Plan (IWRMP), and since that time has been working to implement the recommendations from that plan related to ponds, coastal estuaries and stormwater. The materials contained in this summary report were based on the recently completed IWRMP 2022 Update Report (HW, January 2022) that was presented at a joint meeting between the Select Board and the Board of Health on January 27, 2022. Copies of the report and the presentation to the joint meeting can be found on the Town website. The Town’s drinking water is consistently excellent and has won two awards from the New England Water Works Association as the best tasting water in New England. More than forty percent of the land area that contributes water to the Town’s drinking water wells is protected open space. Nitrogen concentrations in the Town’s water supplies are consistently below 1.0 mg/L, well below the federal standard of 10 mg/L. This is a direct result of the limited development in the vicinity of the wells. However, developed land uses (housing, industrial uses) without proper management may threaten the quality of drinking water. There are about 80 freshwater ponds in Brewster. Based on the last summary of pond water data from 2009 developed by the University of Mass School for Marine Science and Technology along with the Cape Cod Commission (SMAST and CCC, September 2009), five of these ponds have excellent water quality while approximately 15 are classified as impaired (See Figure 2). The impairments relate to nutrient inputs, 2 | P a g e predominantly phosphorus, which contribute to excess algae growth in the ponds. Phosphorus enters the ponds from septic systems, stormwater runoff and fertilizers applied to lawns and gardens. Portions of Brewster lie within the watersheds to Pleasant Bay and Herring River (Figure 3). Nitrogen inputs from septic systems, stormwater, and fertilizers within Brewster have contributed to water quality impairments in these estuaries. While Brewster only has limited access to these coastal resources, the Town has an obligation to reduce nitrogen inputs to support the restoration of the estuaries. Brewster needs to reduce its nitrogen load to Pleasant Bay by 2,262 kg/year (Table 1) and has established a process to meet this goal by signing the Pleasant Bay Watershed Permit in August 2018 along with the Towns of Orleans, Harwich, and Chatham. At the time the permit was issued, the Town had already removed 56% of this load, taking advantage of fertilizer and irrigation management at Captains Golf Course and the adoption of a town-wide fertilizer management bylaw. This was done with minimal cost to the Town. Further low-cost nitrogen management practices being adopted at the golf course will lower the nitrogen threshold that Brewster must meet to 523 kg/yr. Table 1. Pleasant Bay Nitrogen Load Summary Total Nitrogen Reduction Required: 2,262 kg N/year Golf Fertilization Reduction - 930 kg N/year Golf Irrigation Recapture - 230 kg N/year Town-wide Fertilizer Bylaw - 121 kg-N/year Total Nitrogen Removed to Date -1,281 kg N/year Proposed New Reductions at Golf Course - 458 kg N/year Remaining Reduction Needed 523 kg/N/year II. RECENT ACTIONS BY THE TOWN The Town continues to actively manage its water resources. Specific actions over the last five years related to the implementation of the IWRMP and other Town initiatives are summarized below: Drinking Water Protection The Town, in collaboration with the Brewster Conservation Trust, continues to actively pursue open space preservation in the wellhead protection areas that contribute water to the Town’s wells. Between 2018 and 2020 an additional 113 acres of land was preserved to further protect drinking water quality. In addition, the Town is monitoring drinking water quality for per and polyfluoroalkyl substances (PFAS) that that have been found in other drinking water systems on Cape Cod and are associated with a variety of sources, including firefighting foams, food packaging, skin care and clothing products. To date, none of the PFAS compounds have been detected in water pumped from the Town’s water supply wells. Fresh Water Ponds In 2016, the Town developed a Water Resource Atlas for 43 of the freshwater ponds in Brewster (HW, 2016). The atlas highlights the sensitive areas around each pond, including the surface watershed, the groundwater recharge area to each pond, and the septic buffer around each pond http://www.horsleywitten.com/brewsterIWRMP/maps.html. The atlas allows residents to understand the land use around each pond that affects water quality. 3 | P a g e The Mill Ponds Management Plan developed by SMAST (November 2014) provided an overall strategy for the restoration of Walker’s Pond, Upper Mill Pond, and Lower Mill Pond, including recommendations for weed harvesting in Walker’s Pond and an alum treatment in Upper Mill Pond to trap phosphorus in the sediments on the pond bottom. In July 2017, the Town purchased a weed harvester for use in Walker’s Pond and used it to remove approximately 5,000 lbs. of weeds. The harvester continues to be used in Walker’s Pond and in Elbow Pond as well. An alum treatment was also completed for Upper Mill Pond in late 2019 (Solitude Lake Management, January 2020) which is helping to restore water quality in both Upper and Lower Mill Ponds. Coastal Estuaries Brewster continues to work with Orleans, Chatham, and Harwich to implement the Pleasant Bay watershed permit. A study begun in August 2021 is evaluating how much fertilizer applied at the Captains Golf Course actually migrates down to groundwater and flows towards Pleasant Bay. The permit assumes that 20% of the fertilizer leaches through the soil and migrates to the Bay. If the study shows the leaching rate is lower, especially with the updated fertilizer application practices now being used, then the total load to be managed by Brewster will be reduced further. Stormwater Management In November 2021, the Town adopted a stormwater bylaw that will improve how stormwater is managed across Brewster. These regulations will help ensure that stormwater is treated prior to discharge, using best management practices are used to treat for nitrogen and phosphorus as well as minimized sediments that could drain into nearby surface waters. Regulations that explain how the bylaw will be implemented are being finalized by the Planning Board. The bylaw establishes two types of permits that must be acquired depending on the size of a project. A minor permit is required for project that creates between 500-2,500 square feet of new impervious cover and/or results in 10,000 to 20,000 square feet of overall land disturbance. A major permit is required for projects that result in more than 2,500 square feet of impervious cover and/or more than 20,000 square feet of land disturbance. III. KEY ISSUES MOVING FORWARD Pleasant Bay Nitrogen Load Brewster must continue to reduce its nitrogen load to Pleasant Bay by 2,262 kg/year. The low-cost nitrogen management practices that are being adopted at the golf course that will lower the nitrogen threshold that Brewster must meet to 523 kg/yr. The Pleasant Bay Watershed Permit requires that the remaining load reductions required by the Pleasant Bay Watershed Permit can be met through the construction of a neighborhood wastewater treatment plant for a portion of the watershed, the use of nitrogen reducing onsite system treatment systems, or a nitrogen trade with another watershed town through which Brewster funds an expansion of a wastewater treatment facility or other project to reduce the nitrogen load to the Bay. If a neighborhood wastewater treatment plant is needed to meet the nitrogen reduction goals, the 20-year cost would be between $10,000,000 and $15,000,000. This cost could be reduced based on the results of the golf course fertilizer leaching rate study which will be completed in 2023. 4 | P a g e The Pleasant Bay Watershed Permit requires that the Town address nitrogen inputs from future development in the watershed. Based on a recent assessment this could include an additional 1,009 kg N/year. Options are currently being evaluated to minimize this additional load through changes to current zoning and regulatory requirements. Any future load that will be created will have to be offset by further reductions in existing loads. For the Herring River watershed, there is no need to reduce the current nitrogen inputs, but future inputs from increased development will need to be managed. Drinking Water Protection The Town must continue to monitor drinking water quality for per and polyfluoroalkyl substances (PFAS) that that have been found in other drinking water systems on Cape Cod and are associated with a variety of sources, including firefighting foams, food packaging, skin care and clothing products. Fresh Water Ponds The Town is currently working to develop an updated summary of water quality in the major ponds in Brewster, utilizing the annual monitoring data that has been collected since the last summary report in 2009. The Town should consider and pilot test alternative systems to septic for properties that are in the septic buffer around each pond. Per the January 2022 IWRMP Update Report, the proposed pilot testing program for alternative septic systems is estimated to cost approximately $300,000-$350,000. If alternative systems were installed at each property in the septic buffers to the ponds, the total cost would be between $12,000,000 and $15,000,000. IV. BUILDING BLOCK GOAL Protect Brewster's freshwater system to preserve high quality drinking water and maintain or improve the health of our ponds, wetlands and their buffers, and marine watersheds REFERENCES 1. Horsley Witten Group, Inc. January 2022. Integrated Water Resource Management Plan 2022 Update. 2. Horsley Witten Group, Inc. 2016. Water Resource Atlas Fresh Water Ponds, Brewster, Massachusetts. 3. University of Massachusetts School for Marine Science and Technology and Cape Cod Commission. September 2009. Brewster Freshwater Ponds: Water Quality Status and Recommendations for Future Activities. http://brewster-ma.gov/images/stories/BrewsterPonds_FinalReport090109.pdf. University of Massachusetts School for Marine Science and Technology. November 2014. Mill Ponds Management Plan - Walkers Pond, Upper Mill Pond, and Lower Mill Pond. 4. Solitude Lake Management. January 30, 2020. Alum Treatment Final Completion Report, Upper Mill Pond January 2020.