SU0005344_SSNL - Laserfiche WebLink

Home Browse Search

i L LSeptember 30, 2007 NOA Project Number: E07147A L "2. Current and Future On-Site Ground Water Uses Ground water will be used in the proposed development of the recreational vehicle park. L -3.0 SOURCES AND IMPACT OF NITRATE TO GROUND WATER .3.1 Current Off-Site Sources of Nitrate LWe recognize that septic systems,agriculture, and dairies in the area may be the most significant sources of nitrate. Septic tank use in the vicinity is discussed in Section 3.4 of the SSS. L ✓3.2 Contribution of Rainfall An estimate of the quantity and quality of rainfall was required for the nitrate loading analysis. The estimate of deep percolation of rain is based on the average monthly precipitation of rain fall and evapotranspiration for the Lodi area of California. An estimate of potential deep percolation of rain determines whether the average monthly precipitation exceeds average monthly potential Levapotranspiration. If so, then the difference is potential deep percolation. This method does not consider runoff. See Plate 9 for the data and calculation. LAverage potential evapotranspiration was obtained from the California Irrigation Management Information System (CIMIS). Stockton is located within evapotranspiration zone number 12. The average rain fall for the Stockton area was obtained from the Western Regional Climate Center L (www.wrcc.dri.edu),and was found to be 17.57 inches per year for the years 1948 through 2004. L Based on this method, the average deep percolation of rain for the Acampo area is estimated to be 5.76 inches. The nitrate concentration of rain fall was estimated to be 1 mg/L-N (Hantzsche and Finnemore, 1992). Current On-Site Sources of Nitrate LNo current on-site sources are considered besides rainfall on the subject property. 3.4 Future On-Site Sources of Nitrate -,5-4'1 Quantity and Quality of Domestic Wastewater From Proposed Project The following septic use estimates are for the purposes of the nitrate loading analysis and should not Lbe used for septic system design purposes. Typically,use estimates for the sizing of septic systems include a peak use factor,whereas the numbers discussed here are based on long-term averages. L I 4 L.