ARCHIVED REPORTS XR0011078 - Laserfiche WebLink

Home Browse Search

1 Page 13 Gealogica[rec�i�ucs Inc Site Conceptual Model Report Project No 724 2 May 2,2006 2.6.4 Groundwater Contaminant Mass Estimate Calculations The mass of contaminant in the groundwater was determined by calculating the volume of each groundwater contour The volume of each contour was multiplied by a porosity value of ' 45% (clay, Driscoll, 1989), and the 20 foot vertical extent to obtain the volume of water (ft ) in within each contour The cubic feet of water, in each zone, is then converted to liters and then multiplied by the average contaminant load within the contour zone This produces the ' mass of contaminant in each zone The calculations in Table 9, Appendix B show that there is still approximately 0 16 gallon (I ' lb ) of TPH-G dissolved in the groundwater at the site as of the February 2006 monitoring event ' 2.7 Groundwater Beneficial Uses The Regional Water Quality Control Board-Central Valley Region's Basin Plan designates the beneficial uses of groundwater in the San Joaquin Valley as domestic, municipal, industrial and agricultural supply Documentation of uses of the area's groundwater was completed in August 2000 when GTI performed a well survey for a 2,000-foot radius around ' the site The purpose of the survey was to locate any municipal, domestic, or agricultural wells within the 2,000-ft radius and to determine, if possible, the construction of these wells The well survey data is included as Appendix F To meet the survey objective, the following tasks were performed O Geological Technics Inc personnel reconnoitered the site on August 1, 2000 to make ' a physical search for any wells in the area o Specific well logs were requested from the State of California Department of Water Resources (DWR) both to aid in identifying local wells and to specify their ' construction details The DWR well logs that were available for this area are included in Appendix F • Mr Eric Mar of the California Water Services Company was contacted regarding municipal wells serving the area Six potential wells were located within the 2,000-foot radius search area The commercial, ' industrial and residential properties in the area are serviced by private domestic wells and the CWSC Well details are shown in Table 1, Appendix F and the approximate well positions ' are plotted on Map 1, Appendix F Well Survey Data ' As per Mr Mar's communication, the CWSC wells within the 2000' radius are all no longer in service (abandoned) Private residences occupy the sites (Map #'s 1, 3 and 4) and there was no pump equipment observable at the locations The resident at 1642 S California St t was not home during the site visit and the status of the well at that location is unknown (Map #2, this property is historically up gradient of Morita Brothers) Representatives of the Sikh Temple indicated that they receive city water and no well was observed at the 1930 Grant St