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` February 25, 2002 <br /> Job Number: LGOI-397 <br /> Page 5 <br /> ` ground-water flow direction for both seasons was difficult to calculate due to complicated <br /> gradients. The area appears to be within a ground-water"pumping" depression. <br /> A water sample was obtained from the main water well on the located at the Chinchiolo <br /> Fruit Company site on November 30, 2001. The sample was sent to Precision Environmental <br /> ` Laboratory for testing. The samples were tested for the presence of dibromochloropropane <br /> (DBCP) and Nitrate(NO3)per County requirements. <br /> The test results indicated that DBCP was non-detectable (ND) and nitrate was found at <br /> 0.598 mg/L-N(2.7 mg/L-NO3). The result of the nitrate test indicates the ground water is below <br /> the maximum contaminate level set by the United States Environmental Protection Agency of <br /> 10 mg/L-N for nitrate(or 45 mg/L-NO3). See the appendix for a copy of the water quality <br /> analysis. <br /> ` The presence of nitrates and DBCP are not uncommon in shallow ground-water aquifers <br /> in San Joaquin County and other parts of the Central Valley. Nitrate in ground water occurs as a <br /> result of the application of fertilizers, livestock waste, and untreated septic tank waste. Nitrate is <br /> ` mobile and often accumulates in the shallow ground-water zones. <br /> In the early 1900's,natural levels of nitrate in ground water were measured in forty-three <br /> (43)wells throughout the Sacramento Valley by Bryan? It was thought that ground water at that <br /> time was close to "natural" conditions. Based on the work by Bryan, it is estimated that under <br /> "natural" conditions, ground water concentration containing nitrate is no more than about 13.5 <br /> NO3 (3 mg/L-N). Areas having 24.75 mg/L NO3(5.5 mg/L-N)or more are those in which nitrate <br /> concentrations may be increasing' <br /> DBCP was not detected in the water sample. DBCP is a nematocide and soil fumigant <br /> for vegetables, and grapes. It is thought to cause health problems consisting of kidney damage, <br /> liver damage, and cancer. The use of DBCP was discontinued in 1979. The Environmental <br /> Protection Agency(EPA) set the maximum contaminate limit (MCL) at 0.2 parts per billion <br /> 2 Bryan,IC, 1923,Geology and ground-water resources of Sacramento Valley of California:U.S. <br /> Geological Survey Water-Supply Paper 495,285p. <br /> _ _ 3 Hull,L.C., 1984,Geochemistry of Ground Water in the Sacramento Valley,California:U.S.Geological <br /> Survey Professional Paper 1401-B. <br /> �E,SO <br />