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Use Data dated February 20, 2019 (Plates 7 and 8). According to the nitrate map, 13 wells within a one -mile radius of the subject Site have been tested for nitrate. A total of 11 wells were found to contain nitrate at a concentration between 0.1 and 5.0 mg/L-N; nitrate was detected in the remaining two wells at concentrations between 5.1 and 10 mg/L-N. According to the DBCP map, eight wells within a one -mile radius of the Site have been tested for DBCP. No DBCP was detected in any of the wells. 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 color of the skin, as well as headache, dizziness, weakness, and difficulty breathing. Ingestion of high levels of nitrates over time can also lead to gastric problems. 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 ug/L) because it 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 Maximum Contaminant Level Goal (MCLG) for DBCP is zero. On -Site Wells No active wells are located on the Site, though it appears from San Joaquin County records that an old well may be present. One well permit and two additional documents were identified for the Site from among the files of the San Joaquin County Environmental Health Department: • May 1980 well permit for pump replacement. The well is depicted to the east of the drive-in theater's concession stand (4100). • 2019 complaint regarding abandoned well at 4112 S. State Route 99 East Frontage. The complaint was referred to S00013950. LOGE 2201 Page 4