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• Live Oak reviewed the San Joaquin County Environmental Health Department's Water Well Data Table dated March 10, 2009 for nearby addresses that have been tested for nitrate and dibromochloropropane (DBCP). Three wells were identified at addresses within approximately 1.25 miles of the subject Site. All of the wells had been tested for nitrate and DBCP; neither constituent was detected in any of the wells. The Maximum Contaminant Level (MCL) set by the US EPA for nitrate as NO3 is 45 mg/L (10 mg/L-N). The MCL for DBCP is 0.2 µg/L. On-Site Wells Three domestic wells exist on the Site. Six well permits were identified for the Site at the San Joaquin County Environmental Health Department: • November 1973 permit for pump repair at domestic well (9000 W. Howard; appears to be the primary well in the packing shed area). • January 1976 permit for new well (9000 W. Howard; location unclear) • June 1987 permit for new irrigation well. Based on roads drawn in the sketch, this permit may refer to a location off-site to the east. • September 1988 permit for pump replacement at irrigation well (9000 W. Howard; the well location is not indicated). • October 1996 permit for new domestic well (9000 W. Howard; appears to be off- site to the east). • January 2002 permit for new domestic well south of packing shed (9010 W. Howard; appears to be the secondary well in the packing shed area). Copies of the permits have been included in Appendix 4 of this report. Water Sample Live Oak collected a water sample from the domestic well on October 26, 2015. 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 I chain of custody to FGL Environmental,_ Stockton. Neither nitrate nor DBCP was 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 13.5 mg/L-NO3 (3 mg/L-N). Nitrate may be LOGE 1523 Page 4