Laserfiche WebLink
ti. <br /> ` January 26,2006 <br /> NOA Project Number: E05091B <br /> t/ A water sample was taken by Ms. Nancy Rosulek on December 13,2005 from the spigot of the well <br /> on the subject property at 651 West Sargent Road. <br /> y` 4.4 Water Sample Constituents <br /> The water sample was analyzed for nitrate and DBCP. DBCP was not detected in the water sample. <br /> Nitrate u7ne fn»„a 2+ 1 n 9 m ty/T.-NO,,below the maximum contaminant level (MCL) of 45 mg/L- <br /> `` NO3 set by the United States EPA. The analytical reports prepared by Precision Enviro-Tech can be <br /> found in the appendix of this report. <br /> ` Well construction, seals,age and depth of the well screens may play significant part in assessing the <br /> levels of Nitrate and DBCP in various aquifers. Without knowing specific details regarding well <br /> r., construction and condition,it would be difficult to accurately comment of the condition of the <br /> aquifer. Essentially, the water sample concentration approximately indicates the constituent <br /> concentration level of the aquifer from which the well is drawing. It is Neil O. Anderson and <br /> �. Associate's opinion that,in general,near surface aquifers are more likely to have elevated <br /> concentrations of Nitrate and DBCP than the deeper aquifers. However the contaminant <br /> concentration of one aquifer cannot give any indication as to the concentrations of any other aquifer <br /> b, regardless of proximity. <br /> /The presence of nitrates is not uncommon in shallow ground water aquifers in San Joaquin County <br /> and other parts of the Central Valley. Nitrate in ground water occurs as a result of the application of <br /> fertilizers,livestock waste,and untreated septic tank waste. Nitrate is mobile and often accumulates <br /> in the shallow ground water zones. <br /> ,'-"In the early 1900s,natural levels of nitrate in ground water were measured in forty-three (43)wells <br /> b” 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"natural" <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 /> 6 <br />