Laserfiche WebLink
L r.I <br /> L April 24,2006 <br /> NOA Project Number: E06015A <br /> L4.2 Potential Ground Water Contamination Issues <br /> Identifying potential ground-water contamination sources was not part of the scope of work for the <br /> soil suitability study. / <br /> LZ,Z Potential ground-water contamination can occur from a number of sources which often include ley, <br /> leaky underground storage tanks, agricultural activities, dairies, septic systems, and storm water <br /> infiltration. Any past agricultural activities and the present use of septic systems in the area should <br /> be considered potential ground-water contamination sources. <br /> L4.3 Water Sample Location <br /> One well permit was found for the subject property address during file review at EHD on April 10, <br /> 2006.The permit is for the destruction of an old domestic well,well replacement and the installation <br /> iof a pump.The permit was issued in July of 1992 to B.F. Farr. <br /> ` A water sample was taken from the faucet on the residence near the well on March 1, 2006 by Mr. <br /> Colin Stock (Plate 1). <br /> 4.4 Water Sample Constituents <br /> LThe water sample was analyzed for nitrate and DBCP. Nitrate was not detected. The maximum <br /> contaminant level (MCL) set by the US EPA is 45 mg/L-NO3. DBCP was not detected in the water <br /> sample. The analytical reports prepared by FGL Environmental can be found in the appendix of l <br /> Ir this report <br /> L The presence of nitrates is not uncommon in shallow ground water aquifers in San Joaquin County <br /> and other parts of the Central Valley. Nitrate in ground water occurs as a result of the application of <br /> fertilizers,livestock waste, and untreated septic tank waste. Nitrate is mobile and often accumulates <br /> in the shallow ground water zones. <br /> In the early 1900s,natural levels of nitrate in ground water were measured in forty-three (43) wells <br /> f throughout the Sacramento Valley by Bryan (1923). It was thought that ground water at that time <br /> Ir was close to "natural' conditions. Based on the work by Bryan,it is estimated that under"natural' <br /> conditions,ground water concentration containing nitrate is no more then about 13.5 mg/L-NO3 (3 <br /> nig/1,N). Areas having 24.75 mg/L-NO3 (5.5 mg/L-N) or more are those in which nitrate <br /> concentrations may be increasing (Hull, 1984). <br /> L <br /> e <br /> 5 <br /> .,44�. <br /> w <br />