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r October 23, 2009 Page 3 of 10 Our Project Number: LGS0090518 3.2 Potential Groundwater Contamination Issues Identifying potential groundwater contamination sources (such as leaky underground storage tanks, agricultural operations, dairies, septic systems, and storm water infiltration) was outside the scope of our services. However, our firm did provide San Joaquin County a copy of our Surface Sub-Surface Contamination Report (SSCR) for the subject property dated February 10, 2009, which was accepted and reviewed for these issues (NOA, 2009). 3.3 Water Sample Location and Constituents According to an approved tentative parcel map provided by Wood Rodgers, Sacramento, one agricultural wells exist on the Site. No well permits were found during a recent file review at EHD. A well water sample was taken on August 28, 2009 by Jessen Welch from the spigot of the agricultural well located on proposed parcel 20. The water sample was analyzed for nitrate and DBCP. Nitrate was found at 1.8 mg/L which is below the maximum contaminant level (MCL) set by the United States Environmental Protection Agency of 45 mg/L-NO3. DBCP was not detected in the well water sample. The MCL set by the United States Environmental Protection Agency for DBCP is 0.2 pg/L. The analytical reports prepared by FGL Environmental can be found in Appendix C of this report. The presence of nitrates is not uncommon in shallow groundwater aquifers in San Joaquin County and other parts of the Central Valley. Nitrate in groundwater 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 groundwater zones. In the early 1900s, natural levels of nitrate in groundwater were measured in forty-three (43) wells throughout the Sacramento Valley by Kirk Bryan (1923). It was thought that groundwater at that time was close to "natural" conditions. Based on the work by Bryan, it is estimated that under "natural" conditions, groundwater 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). As indicated, DBCP was found in the sample. DBCP is a nematocide and soil fumigant for 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. The sample for nitrate was collected in a sterile plastic container; the sample for DBCP was collected in two sterile glass vials. The samples were then transported on ice and remanded under chain of custody to FGL Environmental, Stockton. The Chain of Custody documentation has been included in Appendix C of this report. ..44 902 Industrial Way•Lodi,CA 95240•209.367.3701 •Fax 209.369.4228 02009 Neil 0.Anderson&Associates,Inc