Laserfiche WebLink
January 7,2003 <br /> Job Number:LG02-026 <br /> Page 3 <br /> A 45 foot boring was drilled on the property by our office on May 9, 2002 as part of a separate <br /> geotechnical investigation for BES Concrete Products. The Job Number is LG02-026 and the <br /> report was dated May 20, 2002. The 45-foot deep geotechnical boring was located <br /> approximately 800 north of the percolation test borings drilled for the Soil Suitability Report. <br /> No ground water was encountered in the 45 foot deep boring. <br /> Our office understands that two water wells exist on the site(Plate 1). The facility presently uses <br /> one 8-inch diameter well constructed in 1989 to a depth of 170 feet. A second idle water exists <br /> somewhere near the southeast corner of the property. No permits or detailed information was <br /> found regarding this well (Plate 1). <br /> The water quality of the aquifer was tested by Fruit Growers Laboratory(FGL), Stockton, on <br /> June 25, 2002. The well was sampled for DBCP and Nitrates along with other general mineral, <br /> inorganic chemicals, and bacterial tests. A copy of the results is attached in the appendix of this <br /> report. DBCP and nitrate are two common indicators of ground-water quality. <br /> The result of the test indicates that DBCP was non-detectable (ND) and nitrate as nitrogen (N) <br /> was 3.3 mg/L-N (reported as 3300 ug/L-N). The result of the nitrate test indicates the ground <br /> water is well below the maximum contaminate level set by the United States Environmental <br /> Protection Agency of 10 mg/L as Nitrate N or 10,000 ug/L-N. DBCP was not detected in the <br /> water sample. <br /> The presence of nitrates and DBCP are not uncommon in shallow ground-water aquifers in San <br /> Joaquin County and other parts of the Central Valley. Nitrate in ground water occurs as a result <br /> 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(43) <br /> wells throughout the Sacramento Valley by Bryan! 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 <br /> 2 Bryan,K., 1923,Geology and ground-water resources of Sacramento Valley of California:U.S. <br /> Geological Survey Water-Supply Paper 495,285p. <br /> pE RSO <br /> D <br /> = W <br /> O � <br /> r <br />