Laserfiche WebLink
(§ 4.0) LOCAL GROUNDWATER AND SURFACE WATER INFORMATION <br /> (§ 4.1) The 2003 Lines of Equal Depth Map published by the San Joaquin County Flood Control <br /> illustrates the groundwater depth to be approximately 105 feet below ground surface (b.g.s.). The <br /> 1999 Lines of Equal Elevation Map illustrates the groundwater directional flow to be in a <br /> northwesterly direction. <br /> No Well Drillers' Logs for nearby domestic wells were found in the microfiche files at EHD. <br /> Therefore, the underground strata under and surrounding the subject property could not be <br /> discerned. From other well drilling projects in this region, it is known that sand, clay and gravel <br /> compose underlying strata. The property is not in the Flood Zone and not subject to flooding. <br /> Surface water runoff from the residential structure, barn and garage is diverted into the surrounding <br /> cropland. <br /> (§ 4.3 and 4.5) The on-site domestic well is located near the southwest corner of the residential <br /> structure. This well was sampled on December 8, 2008 after the pump was operated for 15 minutes <br /> to insure that well casing water and tank water had been purged. A nitrate water sample was drawn <br /> into a one-half liter plastic bottle and the DBCP sample was drawn into three VOC glass vials. <br /> (§ 4.5 and 4.6) All samples were placed in a cooled ice chest and transported to A &L Labs in <br /> Modesto under the attached Chain of Custody found in Appendix B. Test results were received on <br /> December 26, 2008 <br /> (§ 4.4) Water analysis results reveal a medium nitrate concentrations in domestic wells at 29 ppm. <br /> The Maximum Contaminant Level (MCL) for nitrate in drinking water is 45 ppm. DBCP was <br /> Below Detectable Limits (BDL). A summary of the test results are illustrated in Table 2, below. <br /> (§ 4.2) Considering the area has been intensely farmed for the past several decades, these nitrate <br /> concentrations are surprisingly low and may be attributable to the underlying clay strata attenuating <br /> downward migration of nitrate. <br /> TABLE 2 <br /> WELL WATER ANALYSIS <br /> WELL ANALYTECONCENTRATION MAXIMUM CONTAMINANT LEVEL <br /> FOUND (MCIA <br /> On-Site Nitrate(As Nitrate) 29 ppm 45 ppm <br /> Domestic Well <br /> DBCP Below 1)0=4ble Limits- 0.21A/L <br /> BDL <br /> Page -4- <br /> Chesney Consulting <br />