SR0083395_SSNL - Laserfiche WebLink

Home Browse Search

On-Site Wells Two domestic wells and an irrigation well are located on the Site (Plate 2). One well permit was identified for the Site from among the files of the San Joaquin County Environmental Health Department. The permit, dated September 2004, was for a new domestic well at the southern house on the Site. The well was approximately 200 feet deep, with a grout seal at 100 feet. This permit has been included in Appendix 4 of this report. Water Sample Live Oak collected water samples from both domestic wells on the Site on February 23, 2021. Each sample was analyzed for nitrate and dibromochloropropane (DBCP) per San Joaquin County Environmental Health Department policy. As required by the laboratory, each sample was collected in a plastic container and two glass vials for nitrate and DBCP analysis, respectively. Trip blanks were also utilized. The samples were placed on ice and transported under chain of custody to FGL Environmental, Stockton. In the sample from the southern well, nitrate was detected at a concentration of 9.6 mg/L-N, and DBCP was detected at a concentration of 0.02 ug/L. In the sample from the northern well, nitrate was detected at a concentration of 18.9 mg/L-N, and DBCP was detected at a concentration of 0.01 µg/L. 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 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. LOGE 2111 Page 4