Laserfiche WebLink
January 30,2007 <br /> NOA Project Number:E06115A <br /> Page 2 <br /> monthly precipitation exceeds average monthly potential evapotranspiration. If so,then the <br /> difference is potential deep percolation. This method does not consider runoff. See Plate 9 for the <br /> data and calculation. <br /> Average potential evapotranspiration was obtained from the California Irrigation Management <br /> Information System (CIMIS). Stockton is located within evapotranspiration zone number 12. The <br /> average rain fall for the Stockton area was obtained from the Western Regional Climate Center <br /> (www.wrcc.dri.edu), and was found to be 15.98 inches per month for the years 1965 through 1977. <br /> Based on this method,the average deep percolation of rain for the Stockton area is estimated to be <br /> 4.0 inches. The nitrate concentration of rain fall was estimated to be 1 mg/L-N (Hantzsche and <br /> Finnemore, 1992). <br /> 3.5 Nitrate Loading Scenario <br /> A nitrate loading scenario was performed to determine the impact from the proposed project. <br /> Please see section 3.4 of the Nitrate Loading study for details regarding loading details. The scenario <br /> utilizes the variables discussed in Section 3.4 which represent the estimated conditions and uses <br /> associated with this project. The following table presents a summary of the nitrate loading <br /> calculation for the parcel. <br /> Table 2. <br /> S mmary of Nitrate Mass Balance Anal sis. <br /> Result Average Daily Effluent Deep <br /> Leachfield <br /> Acres Flow(Q) Concen- DenitPercolation of <br /> Parcel g/ * (A) (Table 3) tration(Nw) cation fi Rainfall(R) <br /> (mg/L-N) (gpd) (mg/L-N) cation(d) (Plate 9) (in.) <br /> With <br /> 7.3 26 2,212 gpd 45 35% 4.0 <br /> residence <br /> ( tl <br /> esidence 61 26 1,722 gpd 45 35% +.0 <br /> * Maximum contaminant level(MCL) for nitrate in drinking water is 10 mg/L-N. <br /> 3.6 Impact of Nitrate Loading to Nearby Water Sources <br /> Please see section 3.6 of the January 4,2007 Addendum for details regarding nitrate loading impacts <br /> on site,which take into account the current revision for the proposed development. <br />