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LN%� ..� <br /> LNovember 29, 2005 <br /> NOA Project Number: E05003B <br /> L4.2 Potential Ground Water Contamination Issues <br /> It L <br /> L Identifying potential ground-water contamination sources was not part of the scope of work for the <br /> soil suitability study. Potential ground-water contamination can occur from a number of sources <br /> which often include leaky underground storage tanks, agricultural activities,dairies, septic systems, <br /> and storm water infiltration. Agricultural activities and the use of septic systems in the area should <br /> Lbe considered potential ground-water contamination sources. �y` <br /> elk <br /> 4.3 Water Sample Location <br /> One domestic well exists on the site (Plate 1).A sample was taken by Mr. Steve O'Blia of our officeFk, <br /> Lon November 17,2005, at the well head of the domestic well. i xj <br /> No well permits were found for the Site during file review at EHD on November 29, 2005. <br /> 4.4 Water Sample Constituents <br /> The water sample was analyzed for nitrate and DBCP. Nitrate was found i5.9 mg/L-NO3,below <br /> Lthe the maximum contaminant level (MCL) set by the US EPA of 45 mg/L-NO,. DBCP was not <br /> detected in the water sample. The analytical reports prepared by Precision Enviro-Tech can be <br /> Lfound in the appendix of this report. <br /> Well construction, seals, age and depth of the well screens may play significant part in assessing the <br /> levels of Nitrate and DBCP in various aquifers. Without knowing specific details regarding well <br /> construction and condition,it would be difficult to accurately comment of the condition of the <br /> aquifer. Essentially,the water sample concentration approximately indicates the contaminant <br /> concentration level of the aquifer from which the well is drawing. It is Neil O. Anderson and <br /> Associate's opinion that,in general,near surface aquifers are more likely to have elevated <br /> concentrations of Nitrate and DBCP than the deeper aquifers. However the contaminant <br /> concentration of one aquifer cannot give any indication as to the concentrations of any other aquifer <br /> Lregardless of proximity. <br /> 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 <br /> L of fertilizers,livestock waste, and untreated septic tank waste. Nitrate is mobile and often <br /> accumulates in the shallow ground water zones. <br /> L <br /> 4 <br /> L <br /> L <br /> 5 <br /> L -44 <br /> L <br />