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DBCP; no DBCP was detected in four wells, and DBCP was detected over 0.2 µg/L in the remaining two wells. The Maximum Contaminant Level (MCL) set by the US EPA for nitrate is 10 mg/L-N; the MCL for DBCP is 0.2 µg/L. On-Site Wells One domestic well is located on the Site. Three well permits were identified for the Site at the San Joaquin County Environmental Health Department: • October 1990 permit for new domestic well. • October 1990 permit for destruction of old well. • June 2018 permit for pump replacement at domestic well. The well permits have been included in Appendix 4 of this report. Water Sample Live Oak collected a water sample from the domestic well on the Site on November 13, 2018. The sample was analyzed for nitrate and dibromochloropropane (DBCP) per San Joaquin County Environmental Health Department policy. As required by the laboratory, the sample was collected in a plastic container and two glass vials for nitrate and DBCP analysis, respectively. A trip blank was also utilized. The sample was placed on ice and transported under chain of custody to FGL Environmental, Stockton. Nitrate was detected in the sample at a concentration of 7.2 mg/L-N. DBCP was not detected in the sample. Nitrate is commonly detected in shallow ground water aquifers of the Central Valley. Application of fertilizers, livestock waste, and untreated septic tank waste can all contribute to nitrate in ground water. Nitrate is mobile and tends to accumulate in shallow ground water zones. Based on work in the Sacramento Valley from the early 1900s, it is estimated that under "natural" conditions, ground water contains nitrate at concentrations no more then about equivalent to 3.0 mg/L-N. Nitrate may be increasing in areas with concentrations of 5.5 mg/L-N or more (Hull, 1984). The US EPA has set the Maximum Contaminant Level (MCL) for nitrate as N at 10 mg/L-N. DBCP is a nematocide and soil fumigant for vegetables and grapes. It is known to cause male reproductive effects and is classified as a probable human carcinogen. Most domestic use of DBCP was discontinued in 1977 through 1979. The US EPA set the MCL at 0.2 parts per billion (ppb, equivalent to pg/L) because it believes that, given present technology and resources, this is the lowest level to which water systems can LOGE 1916 Page 4