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Flushing Proposal <br /> This is a proposal to reduce Mashpee's Nitrogen pollution in the Popponesset and Waquoit watersheds. <br /> Quantifying the present Waste Water Nitrogen contribution to the Mashpee watersheds: <br /> 1.10,000 household "units" <br /> 2.2.5 persons per unit producing a total of 125 gallons of WW per day <br /> 3.8500 Units on Title 5 systems yielding 25 Mg. N/L <br /> 4.1200 units on private systems yielding 15 Mg. N/i_ <br /> 5.300 units on I/A systems yielding 15 Mg. N/L <br /> Total volume 1,250,000 gallons of WW per day. <br /> Annual Nitrogen impact of WW on,Mashpee's Watersheds: <br /> 8,500 x 25 Mg. N/I 212,500 <br /> 1,200 x 7 Mg. N/L = 8,400 <br /> 300 x 15 Mg. NA — 4,500 <br /> 10,000 Total units 225,400 <br /> 225,400/10,000=22.54 Mg. N/L for average unit output <br /> 22.54 Mg. N/L x 3.785 L/gallon=85.31 Mg. N/gal <br /> .085 Grams N/gal x 1,250,000 gal/day= 106,250 Grams N/day <br /> 106,250 Grams N/day / 454 Grams/lb. = 234 Ibs. day <br /> 234 lbs. N x 365 days = 85,421 lbs. Nitrogen per year in our WW <br /> This is the equivalent of 8,500 50#bags of 20% Nitrogen fertilizer <br /> "Flushing" concept is to reintroduce WW at 3 Mg. N/L into the upper portions of the watersheds. This can <br /> be accomplished by upgrading the existing private WW,plants to yield 3 Mg. N/L, upgrading their volume <br /> where practical, and building enough new capacity at 3 Mg. N/L to process 50% of Mashpee's total WW <br /> volume from high density areas. Since these units and plants are in the upper portions of our watersheds, <br /> the low-Nitrogen WW will,through dilution,flush Nitrogen from the watersheds and aquifers. <br /> The impact of processing 625,000 Gallons/day to 3 Mg. N/L would remove 37,006 lbs .N/year or 43% of <br /> Mashpee's WW Nitrogen from the upper portions of our estuaries. The reduction in Nitrogen loading plus <br /> the long "dwell time" of low Nitrogen WW will help leach Nitrogen out of the estuaries. The balance (50%) <br /> of the town's WW,from low density areas, by definition/location, contribute less than half of the Nitrogen <br /> pollution. Attenuation, declining household members, and actual water use closer to 30 Gal. per Day per <br /> person vs. the 50 Gal per day used for the "Flushing" calculations means the actual Nitrogen impact from <br /> present WW volume is considerably less. Implementation of this proposal can quite possibly result in <br /> meeting mandated levels. <br /> 1NL 4/18/2011 <br />