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'-' December 23, 2005 <br /> NOA Project Number: E05174A <br /> /In the early 1900s, natural levels of nitrate in ground water were measured in forty-three (43) wells <br /> throughout the Sacramento Valley by Bryan (1923). It was thought that ground water at that time <br /> was close to "natural" conditions. Based on the work by Bryan,it is estimated that under"naturae' <br /> " conditions,ground water concentration containing nitrate is no more then about 13.5 mg/L-NO3 (3 <br /> 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 (Hull, 1984). <br /> �/DBCP is a nematocide and soil fumigant for vegetables and grapes. It is thought to cause health <br /> problems consisting of kidney damage, liver damage, and cancer. The use of DBCP was <br /> discontinued in 1979. The Environmental Protection Agency (EPA) set the maximum contaminant <br /> limit (MCL) at 0.2 parts per billion (ppb) because the EPA believes that given present technology <br /> and resources, this is the lowest level to which water systems can reasonably be required to remove <br /> this contaminant should it occur in drinking water. <br /> r <br /> 4.5 Well Water Sample Collection, Handling, and Transportation <br /> # The water sample for nitrate was collected in a sterile plastic container,and the sample for DBCP <br /> y.5 was collected in two sterile glass vials. The samples were then transported on ice and remanded <br /> k4 * under chain of custody to Precision Enviuro-Tech, Stockton. <br /> 4.6 Chain of Custody <br /> The laboratory report and chain of custody will be sent to EHD when the testing is completed. It is <br /> assumed that the laboratory report will be complete in the next few days. <br /> 5.0 SOIL PROFILE AND GEOLOGIC INFORMATION <br /> The Site is depicted on a geologic map as having Tertiary Laguna Formation containing arkosic <br /> gravel, sand and silt. In addition to the Tertiary Laguna Formation, the site contains Quaternary <br /> Turlock Lake Formation composed of arkosic alluvium (Plate 7). <br /> The surface and near surface soils located at the Site are reported by the San Joaquin County Soil Survey <br /> ' to be composed of several different soil types. Table 3 presents a summary of selected soil <br /> properties (See Plate 8). <br /> r <br /> 1 T <br /> a <br /> 7 <br />