SU0005084 SSNL - Laserfiche WebLink

Home Browse Search

fto January 4, 2006 NOA Project Number: E05166B Table 1. ` Maximum Quantity of Effluent for Parcels 1-7. Category Total People per Average Quantity per Average Daily Flow ft= Category Person Per Parcel Residential (Parcel 1-4, 7 70 gal/day/resident 7 resident/resident 490 gp 6&7) Red e15a d 70 gal/day/resident 8 residents 560 gP /resident a Note — gpd is gallons per day. For Parcels 1 through 4, 6 and 7, the total daily waste water quantity is 490 gallons per day. For Parcel 5, the total daily waste water quantity is 560 gallons per day. The average total nitrogen concentration of domestic waste water is normally considered to range •� from 20 to 85 mg/L-N with 35 to 45 mg/L-N being typical (Crites and Tchobanoglous, 1998). For the purposes of the nitrate to g estimate, a long-term average concentration for total nitrogen in waste water is estimated to40 mg/L-N. 4.4.2 Denitrification Estimate �. Denitrification is an important process which occurs within the leach field whereby certain bacteria utilize the oxygen in the nitrate (NO3) and release nitrogen gas (N, to the atmosphere. Denitrification is expressed as a percentage, and the normally accepted range is 10 percent to 354 u .. percent. Soils with higher clay content, moist soil conditions, hijzh pH, and organic material denitrify by about 35 percent, and soils with high sand content and fast percolation rates are ; estimated to denitrify at a lower rate, about 10 percent to 15 percent. << A denitrification factor of 35 percent was selected for the Site due to very slow percolation rates observed and fairly dark surface soils. /4.5 Nitrate Loading Scenario A nitrate loading scenario was performed to determine the impact from the proposed project. The scenario utilizes the variables discussed previously which represent the estimated conditions and uses associated with this project. The following table presents a summary of the nitrate loading calculation for each parcel. 5