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Den Hartog Property Page 4 of 9 Our Project Number: LG5080514 May 23, 2008 ✓4.4 Water Sample Constituents The water sample was analyzed for nitrate and DBCP. DBCP was not detected in the sample from the well. Nitrate was found to be 79.0 mg/L-NO3 which is above the maximum contaminant level (MCL) of 45 mg/L-NO3 set by the Environmental Protection Agency (EPA). The analytical reports prepared by FGL Environmental can be found in the appendix 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. N 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). DBCP was not 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. Y 4.5 Well Water Sample Collection, Handling, and Transportation 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. j,' 4.6 Chain of Custody The Chain of Custody document has been included in the appendix of this report. ,.,64 902 Industrial Way•Lodi,CA 95240•209.367.3701 •Fax 209.369.4228 02008 Neil O.Anderson&Associates.I=