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Water Sample Live Oak collected a water sample from the domestic well on the Site on June 6, 2018. The sample was analyzed for nitrate per San Joaquin County Environmental Health Department policy. As required by the laboratory, the sample was collected in a plastic container. 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 7.6 mg/L-N. 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 increasing in areas with concentrations of 24.75 mg/L-NO3 (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. 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. Sources of Nitrate to Groundwater Off-Site Sources of Nitrate Many sources can contribute to ground water nitrate contamination, including agricultural activities, dairies and cattle ranches, septic systems, and storm water infiltration. Septic systems and dairies have been found to be the most significant sources of nitrate in ground water. Orchards that require fertilization in sandy soils are also a significant source of nitrate contamination in shallow or sandy aquifers in San Joaquin County. The general area consists of orchards, open agricultural land, and rural residences. For these land uses, septic systems and agricultural activities would likely be the largest contributors to nitrate contamination. LOGE 1833 Page 4