ARCHIVED REPORTS_XR0005114 - Laserfiche WebLink

Home Browse Search

Closure Report 16 Golden Grain Manteca Bean Facility,299 Moffat Boulevard,Manteca,California July 16, 19% I study performed in 1990 determined a radius of Influence ranging from 80 feet to 90 feet at the maximum the air flow rate being pulled from the test extraction wells(130 cfm) The:readings ' collected on April 23, 1996, showed influence at C4 approximately 35 feet from the nearest extraction well, MW-2, and influence at C8 approximately 25 feet from the nearest extraction well, ' MW-4 The data collected demonstrates that soli in the vicinity of soil cores C4 and C8 is within the radius of influence of the vapor extraction system 4.9.4 Physical Properties Analysis of Soil Samples ' Four soil samples were retained for laboratory analysis for effective porosity, bulk density, and total organic carbon (TOC) content The laboratory reported effective porosity ranged from 35 3%to 43 5% The bulk density ranged from 151 grams per cubic centimeter(g/cc)to 174 g/cc The TOC ' ranged from 230 mg/kg to 630 mg/kg Copies of the laboratory reports and the chain-of-custody record are contained in appendix E 1 4.2 Current Groundwater Conditions Ongoing groundwater monitoring and sampling has been performed since February 1987 for the ' purpose of evaluating the groundwater gradient and distribution of dissolved hydrocarbons in groundwater The latest groundwater monitoring and laboratory analyses data was collected on ' May 21, 1996, and reported in the Second Quarter 1996 Status Report submitted to the SJCPHS on June 21, 1996 (Groundwater Technology 1996) ' Results of the groundwater monitoring were used to calculate the groundwater elevations for preparation of a potentiometric surface map for the site (figure 21) As Indicated on figure 21 the ' groundwater gradient direction beneath the site is generally to the north at an average gradient of 0 007 ft/ft The general gradient at the southern portion of the site is slightly greater than that for the northern portion The gradient direction and magnitude are consistent with historic data Historic ' groundwater elevation data is summarized in table 4 Of the 14 monitoring wells sampled in May 1996, dissolved concentrations of TPH-g and benzene were detected in wells MW-1, MW-4, MW-5, and MW-7 Maps showing reported values of benzene concentrations and dissolved TPH-g are included as figures 22 and 17, respectively Historical and ' recent groundwater analytical data are summanzed in table 5 The laboratory analytical reports and 40=21i 3,CR _ FLUOR DANIEL GTI