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EXECUTIVE SUMMARY <br /> Like many Cape Cod estuaries,Pleasant Bay(the Bay) is threatened by excessive loading of <br /> nitrogen from development within its watershed. While wastewater from on-site septic systems <br /> is the primary source of nitrogen loading,the focus of this project is on controlling fertilizer <br /> loadings to the Bay,which are an important secondary source of nitrogen within the watershed. <br /> Based on a review of the current fertilizer loading information, and an analysis of options to <br /> control future loading, an action plan has been developed that has the potential to reduce the <br /> overall controllable nitrogen load to the Bay by 5.2%. <br /> This project, funded through a grant to the Pleasant Bay Alliance from the Cape Cod Water <br /> Protection Collaborative, has been designed to investigate the following fertilization issues: <br /> • What is the current contribution of nitrogen from fertilizers in the Pleasant Bay watershed <br /> and how significant is it in comparison to that provided by wastewater discharges? <br /> • What current regulations exist in the four Pleasant Bay watershed towns (Brewster, <br /> Chatham, Harwich, and Orleans)that support the management of fertilizer use? <br /> • Are there examples from other communities around the country that could be considered <br /> for use in the Pleasant Bay watershed? <br /> • What specific recommendations should be considered for Pleasant Bay,what issues exist <br /> with their implementation, and what credit towards the nitrogen total maximum daily <br /> loads(TMDLs) can be achieved for each? <br /> The Horsley Witten Group, Inc. (HW) and Effective Organics began this project with an in-depth <br /> review of the current and future nitrogen loadings to Pleasant Bay based on land use analyses <br /> conducted by the Massachusetts Estuaries Project(MEP) as part of their development of nitrogen <br /> loading limits or Total Maximum Daily Loads (TMDLs) for the Pleasant Bay sub-watershed. <br /> TMDLs are critical contaminant or pollutant thresholds that are protective of the habitat within <br /> the Bay. The nitrogen TMDLs are currently being used as the target that must be met by towns <br /> within the watershed as part of their watershed planning efforts. A significant reduction below <br /> current nitrogen loading rates is often needed to meet these TMDLs. <br /> Using the MEP model for Pleasant Bay,HW quantified the current contribution of nitrogen from <br /> fertilizers in the Pleasant Bay watershed and how this compares to wastewater contributions. <br /> HW reviewed fertilizer assumptions from the model, and resulting nitrogen loading estimates for <br /> each of the 95 sub-watersheds to the Bay, as delineated by the MEP model(Figure ES-1). <br /> Fertilizer applications comprise 15.4%of watershed-based, or controllable nitrogen loading to <br /> Pleasant Bay. Golf course fertilizers represent the largest controllable source of nitrogen <br /> fertilizer input to the Pleasant Bay watershed at 8.3%,with residential lawn fertilizers <br /> representing 6.8%of the watershed load. The MEP model estimates that nitrogen loading from <br /> residential lawn fertilizer could potentially increase by 40%under residential build-out <br /> conditions. <br /> Pleasant Bay Fertilizer Management Plan i Horsley Witten Group, Inc. <br /> Final Report December 2010 <br />