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i L ' `J G L November 17,2005 NOA Project Number: E05152 our office on November 2, 2005. 4.4 Water Sample Constituents The water sample was analyzed for nitrate and DBCP. Nitrate was found at 8.03 mg/L-NO3,well (�A) below the maximum contaminant level (MCL) set by the US EPA of 45 mg/L-NO3. The result of ` the DBCP analysis was not available at the time of this report. The DBCP result will be sent in a separate letter. Please review addendum letter for the result. The analytical reports prepared by Precision Enviro-Tech can be found in the appendix of this report. The presence of nitrates is not uncommon in shallow ground water aquifers in San Joaquin County and other parts of the Central Valley. Nitrate in ground water occurs as a result of the application L of fertilizers, livestock waste, and untreated septic tank waste. Nitrate is mobile and often accumulates in the shallow ground water zones. ` In the early 1900s,natural levels of nitrate in ground water were measured in forty-three (43) wells throughout the Sacramento Valley by Bryan (1923). It was thought that ground water at that time was close to"natural' conditions. Based on the work by Bryan,it is estimated that under"natural' 6, conditions,ground water concentration containing nitrate has a concentration of no greater then about 13.5 mg/L-NO3 (3 mg/L-N). Areas having 24.75 mg/L-NO3 (5.5 mg/L-N) or more are those in which nitrate concentrations may be increasing (Hull, 1984). L DBCP is a nematocide and soil fumigant for vegetables and grapes. It is thought to cause health problems consisting of kidney damage,liver damage, and cancer. The use of DBCP was ` discontinued in 1979. The Environmental Protection Agency (EPA) set the maximum contaminant limit (MCL) at 0.2 parts per billion (ppb) because the EPA 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. 4.5 Well Water Sample Collection, Handling, and Transportation The samples were collected in appropriate glass vials. The samples were then transported on ice and 0K,5) remanded under chain of custody to Precision Enviro-Tech, Stockton. 4.6 Chain of Custody LThe Chain of Custody document has been included in the appendix of this report. LG� 411. 7G Cr 3,"AV A1rPWM-,Z) 5.0 SOIL PROFILE AND GEOLOGIC INFORMATION The Site is depicted on the USGS Geology of the Fresh Gmund-Water Basin of the Central Valley, California L (Page, 1986), as consisting of Miocene to Holocene continental rocks and deposits (Plate 7). This 5 L '444