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Popponesset Bay: Wetland Restoration for Enhanced Nitrogen Removal. <br /> Among the proposed scenarios, abandoned cranberry bogs along the Santuit River were considered as <br /> a means to measure the natural nitrogen attenuation the bogs currently create. It was estimated that the <br /> rate could be boosted to 60%with improvements in the system such as additional water movement. <br /> Improved natural removal of nitrogen reduces the need for a wastewater treatment system. <br /> Popponesset Bay: Enhanced Natural N Removal <br /> Another green solution involves the oyster program which is removing some nitrogen from the <br /> Mashpee River. Quaker Run ponds are also removing nitrogen. Mr. Eichner noted the challenge of <br /> receiving credit for the natural removal of nitrogen as it relates to the regulatory environment. Given <br /> the cost of wastewater treatment,Mr. Eichner stated that it is worthwhile to consider opportunities for <br /> the natural removal of nitrogen. <br /> Sewer Commission Wastewater Scenarios-Timeline <br /> Mr. Eichner presented a timeline reflecting the current scenarios,beginning in April 2008 and <br /> concluding with acceptance of the database'and nitrogen loads by the wastewater consultants at the end <br /> of October 2009. Soon after,the water quality analysis was initiated. <br /> Sewer Commission Wastewater Scenarios <br /> Scenarios 1,2,4 and 5 were recommended by Stearns and Wheler and Scenario 3 was recommended <br /> by Lombardo Associates. <br /> Scenario 1-No expansion of existing WWTF (wastewater treatment facilities)which currently have 10 <br /> ppm TN (total nitrogen) effluent; the addition of 4 new WWTF with 3 ppm TN effluent; 5 discharge <br /> sites and 380 IIA(innovative alternative) septic systems that would remove additional nitrogen with 10 <br /> ppm TN effluent. <br /> Scenario 2-Upgrade or expand existing facilities, as practical,reducing effluent to 3 ppm; add 4 new <br /> WWTFs with 3 ppm TN effluent; 4 discharge sites; no IA systems <br /> Scenario 4-"Fair Share Discussions"includes 3 new WWTFs with 3 ppm TN effluent; 3 discharge <br /> sites; approximately 130 new I/A septic systems with 10 ppm TN effluent <br /> Scenario 5-"Centralized Approach"includes 2 new WWTFs(l each in Mashpee and Sandwich)with <br /> 3 ppm.TN effluent; 5 effluent discharge sites; convert all existing private Mashpee WWTFs to <br /> pumping stations connected to a single centralized Mashpee WWTF <br /> Scenario 3-`Nitrex Based Decentralized Approach"includes 16 WWTFs with 3.75 ppm TN effluent; <br /> 16 discharge sites; all new or expanded on-site septic system flow treated with on-site Nitrex with 3.75 <br /> ppm TN effluent <br /> Sewer Commission Wastewater Scenarios-Table <br /> Mr. Eichner shared a table of figures which categorizes different types of treatment for each scenario. <br /> Mr. Eichner stated that the total nitrogen effluent assumed in these cases is 23.63, a standard factor for <br /> MEP analysis. Mr. Eichner noted that the total flows do not add up across the board due to wild cards <br /> in some scenarios, such as use of New Seabury which is outside of the watershed area. <br /> 2 <br />