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Most of the nearby land is agricultural, including many orchards, elevated nitrate levels in the area likely derive from fertilizer application on these properties. On-Site Wells One domestic well is currently located on the Site. Two well permits were identified for the Site from among the files of the San Joaquin County Environmental Health Department: • July 1995 permit for replacement domestic well and destruction of old well; the permit notes that the new well is 220 feet deep and has a 100-foot grout seal. • August 1995 permit for pump installation at domestic well. These 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 May 28, 2019. 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. Trip blanks were 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 11.7 mg/L-N. DBCP was not detected in the water sample. The laboratory analytical results are attached as Appendix 5 of this report. 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 3 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 at 10 mg/L-N. Although nitrate is a naturally-occurring compound necessary for plant growth, it can cause health problems when present at high levels in drinking water. The most common health effect of nitrates in water is methemoglobinemia, or blue baby syndrome, which results in reduced oxygen supply to vital tissues. Pregnant women and certain others can also develop methemoglobinemia. Symptoms include a bluish LOGE 1930 Page 4