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FINDINGS AND DISCUSSION The nitrate loading concentration from the residential units determined in the referenced Studies has subsequently been recalculated and is now 14 ppm nitrate-nitrogen, still 4 ppm over the MCL. Another nitrate loading equation parameter changed was the wastewater volume in average daily flow(ADF)from 450 gallons per day(gpd)to 400 gpd, which equates to 146.000 gallons per year. The recalculated average concentration of nitrate-nitrogen in the recharge water of 14 ppm equates to 0.000116702 lbs of nitrate-nitrogen per U.S. gallon. Multiplying, we find a potential total nitrate-nitrogen concentration in the recharge wastewater, in lbs,to equal: 0.000116702 lbs NO -N/gallon x 146,000 gallons (Total wastewater flow volume)= 17 lbs of nitrate-nitrogen in the recharge water. Mr. Thornton applies 275 units (pounds per acre)of nitrogen fertilizer each growing season(or per year), based upon his average yield of 2,750 lbs almond kernels/ac. Nitrogen applied is primarily in the ammonium form from synthetic N fertilizers injected through his irrigation system (fertigation) and contributions of N from his irrigation water. His irrigation system is composed of microsprinklers and he applies 3.0 ft of irrigation water per season. Taking the subject parcel acreage of 1.37 acres x 325,851 gallons/acre-fl =446,416 gallons per foot of irrigation water applied x 3.0 ft total = 1,339,248 gallons applied. Converting 275 lbs N applied/ac x 1.37 ac = 377 lbs N applied_ 1,339,248 gals irrigation water applied=0.000282 lbs N/gallon of irrigation water. 0.000282 lbs N/gallon= 33.9 ppm N in the applied irrigation water. However, the almond trees utilize a percentage of this nitrogen concentration,with the remaining fraction potentially entering the groundwater. This is referred to as the Nitrogen Use Efficiency (NUE)Factor. It is the fraction of applied nitrogen that is absorbed and used by the plant. It is generally regarded by regulatory agencies to be 70% for almond trees (See Ref. 2, Pg 28).' Therefore,taking 70%of 33.9 ppm N utilization=33.9 x (1- 0.70)= 10.2 ppm N that may potentially enter the groundwater. CONCLUSIONS The nitrogen loading calculations above illustrate that whether the subject Parcel is planted in almonds, or developed with a primary and second unit dwelling, the loading from both sources exceeds the drinking water MCL of 10 mg/L N. It is my professional opinion that given the surrounding agricultural land use that will not change for decades, and the fact that both agricultural sources and domestic wastewater sources exceed the MCL, nitrogen loading mitigation does not warrant pressurizing the effluent from the proposed second unit dwelling. It is my professional opinion that increasing the size of the septic tank from a 1,600 gallon to a 2,000 gallon tank, thus potentially increasing the total N removal up to 30%(See Ref. 1, Pg. 12), is a much more plausible approach to decrease nitrogen loading than effluent pressurization. Page 2 of 3 Chesney Consulting