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Mr:George Rose - <br /> ;k March 1,2002 <br /> Page 2 <br /> The quantity of household waste water was estimated to be 50 gallons per person per day_ <br /> In a residence of three (3) or(4) bedrooms,the typical occupancy would probably range,between. i <br /> two (2) to four(4)persons per day resulting in a daily waste water flow between 100 to 200 <br /> gallons per day. The potential impact of a.legally permitted second dwelling unit containing <br /> three(3)bedrooms.is estimated to include an additional three (3)people to,the property. The <br /> second dwelling unit could potentially contribute and additional 150 gallons per day to the site. <br /> See Table 2 for-the total estimate daily effluent flow. <br /> _ Table 2. <br /> Total'Daily Effluent. <br /> (see worksheets in Appendix for calculations) <br /> Category Quantity Maximum Daily effluent quantity for each analysis <br /> Occupancy <br /> Main 50 4 people 50 gallons/day/person x 4 people=200 gallons/day <br /> Residence gallohs/day/person <br /> With 50 Additional <br /> Second gallons/day/person 3 people 50 gallons/day/person x 7 people=350 gallons/day <br /> Dwelling (4+3=.7) <br /> Unit <br /> The average nitrate concentration of the typical residential septic waste is normally <br /> considered to be 45 mg/L-N.' The deep percolation of rain for the site was estimated to be 6.79 <br /> inches (Plate 2). The concentration of nitrates in rain water is estimated to be 0.17 mg/L-N. ' <br /> according to work presented by Hantzsche and Finnemate.l A denitrification factor of 25%was <br /> utilized due to fine grained soils encountered at the site. <br /> The nitrate loading analysis was performed for the smallest parcel size of 2.10 acres. <br /> This.is the most conservative calculation since the impact is the less for larger parcels. Table 3 <br /> presents a summary of the nitrate loading analysis which considers nitrate'sources from septic <br /> systems and rainfall: " <br /> 2 Otis,R j.,Boyle,W.C., 1980,Design manual,onsite wastewater treatment and disposal systems:U-S. . <br /> Environmental Protection Agency,EPA 62511-80-012. (See page 100,table 6=1): <br />