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December 11,2006 NOA Project Number: E06141A and storm water infiltration. Agricultural activities and the use of septic systems in the area should i be considered potential ground-water contamination sources. 4.3 Water Sample Location One domestic well and one agricultural well exist on the site. Two well permits were found during file review at the EHD on December 6, 2006. The permits indicate the locations of the wells. These permits can be found in the Appendix of this report.A water sample was taken by Mr.Jessen Welch of our office on November 13, 2006 from the spigot of the domestic well. 4.4 Water Sample Constituents The we ater s 'triple was analyzed for nitrate and DBCP. Nitrate was found t 22.7 m L-N031 which s below a maximum contaminant level (MCL) set by the US EPA of ' mg/L� 03. DBCP as not etected in the water sample. The analytical reports prepared by Environm can be found in the appendix of this report. The presence of nitrates is not uncommon in shallow ground water aquifers in San Joaquin County and other parts of the Central Valley. Nitrate in ground water occurs as a result of the application of fertilizers,livestock waste, and untreated septic tank waste. Nitrate is mobile and often accumulates in the shallow ground water zones. In the early 1900s, natural levels of nitrate in ground water were measured in forty-three (43) wells throughout the Sacramento Valley by Bryan (1923). It was thought that ground water at that time was close to "natural" conditions. Based on the work by Bryan,it is estimated that under"natural' conditions,ground water concentration containing nitrate is no more then about 13.5 mg/L-NO3 (3 mg/L-N). Areas having 24.75 mg/L-NO3 (5.5 mg/L-N) or more are those in which nitrate concentrations may be increasing (Hull, 1984). d in the water sample. DBCP is a nematocide and soil fumigant DBCP was not detected ant for p g vegetables and grapes. It is thought to cause health problems consisting of kidney damage,liver damage, and cancer. The use of DBCP was discontinued in 1979. The Environmental Protection Agency (EPA) set the maximum contaminant limit (MCL) at 0.2 parts per billion (ppb) because the EPA believes that given present technology and resources, this is the lowest level to which water systems can reasonably be required to remove this contaminant should it occur in drinking water. 6