Laserfiche WebLink
Sources of Nitrate <br /> Septic systems and dairies have been found to be the most significant sources of nitrate <br /> in ground water. Orchards that require fertilization in sandy soils are also a significant <br /> source of nitrate contamination in shallow or sandy aquifers in San Joaquin County. IS <br /> Contribution of Rainfall <br /> An estimate of the quantity and quality of rainfall was required for the nitrate loading <br /> analysis. An estimate of the deep percolation of rain was based on a calculation using <br /> average monthly precipitation of rainfall and evapotranspiration rates for the area. The <br /> calculation first determines whether the average monthly precipitation exceeds average <br /> monthly potential evapotranspiration. If so, then the difference is potential deep <br /> percolation. This method does not consider runoff. Based on the calculation shown in <br /> the following tabi te=-Aercolation of rain (recharge) for the Lockeford, California <br /> area is foundA6 be 7.38 inches,per year. <br /> Table 3. Estimate of Deep Percolation of Rainfall for Lockeford, CA. <br /> Average Rain- Average Potential Annual Potential Deep <br /> Month Fall (inches) Evapotranspiration (inches) Percolation of Rain <br /> (inches) <br /> January 3.58 0.79 2.79 ✓ <br /> February 3.40 1.55 1.85 <br /> March 2.33 3.28 None <br /> April 1.53 5.17 None `` <br /> May 1.08 6.58 None ( /•2J <br /> June 0.19 7.51 None <br /> July 0.00 7,87 None <br /> August 0.04 6.85 None <br /> September 0.10 5.11 None <br /> October 0.98 3.29 None <br /> November 1.63 1.54 0.09 <br /> December 3.41 0.76 2.65 ✓ <br /> Totals 18.27 50.3 7.38 <br /> !Votes: CIMIS evapotranspiration information at wwwcimis,water.ca.gov/cimis/for station 16 . Rainfall <br /> average from station 040010 (Acampo, CA)at www.wrcc.ciri.edu. Closest available stations to Site were selected. <br /> Nft- LOGE 1402 Page 10 <br />