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Live Oak previously sampled the domestic well on March 22, 2 6, before construction of the church facility; nitrate was detected at a concentration of 11.4 mg/L-N, and DBCP was not detected (Live Oak, 2016; Appendix 5). The decreased rate concentration between 2016 and 2019 suggests that the existing church septic system has not contributed to elevated nitrate levels in the ground water; nitrate in the area may derive from other sources. 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 as nitrogen 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. Soil Profile and Geologic Information The Site is depicted on the Preliminary Geologic map showing Quaternary deposits of the Lodi Quadrangle, California (Marchand and Atwater, 1979). The Site is depicted within a map unit of the Modesto Formation lower member described as "Qm, and Qmjb deposits overlain by 0.5 to 2 m of Qm2 deposits." The Qm, unit is described as "arkosic alluvium forming Mokelumne River alluvial fan; chiefly sand; probably glacial outwash," the Qm,b unit is described as "basin alluvium derived from Mokelumne and Calaveras Rivers; includes arkosic alluvium, probably glacial outwash, and locally- derived materials; chiefly fine sand and silt," and the Qm2 unit is described as "arkosic alluvium forming Mokelumne River alluvial fan; chiefly sand, becoming finer-grained toward fan toe; probably glacial outwash" (Plate 11). LOGE 1917 Page 5