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' \%00_1 N-"O <br /> Sierra-Pacific Groundwater Consz(ltants, Inc. Y <br /> Geologists, Engineers, and Compliance Specialists <br /> September 11, 1997 ' , ?„ <br /> ' r: } 6 <br /> Ms. Wendy Wyels, SLIC Unit <br /> Central Valley - Regional Water Quality Control Board <br /> 3443 Routier Road, Suite A <br /> Sacramento, California 95827-3098 <br /> Subject: Third-Quarter 1997 Monitoring Report and Request For Closure, Cargill's Former <br /> Molasses Feed Product Facility, Port Road No. 8, Stockton, California: Sierra-Pacific <br /> Project No. 96-128.05 <br /> Dear Ms. Wyels: <br /> The Third-Quarter 1997 Monitoring Report for the molasses-based animal feed product facility at Port Road <br /> No. 8, Stockton, is enclosed for your consideration. On behalf of Cargill, Inc. (Cargill), we have also <br /> included a brief description of the site, and a follow-up request for site closure. <br /> Current Site Conditions <br /> As of September 1, 1997, all of the aboveground storage tanks, piping, product mixers, office buildings, <br /> warehouses, and ancillary structures have been demolished and removed from the site. Old concrete <br /> foundations, containment structures, concrete pads, and sections of asphaltic concrete paving have been <br /> excavated, crushed, blended with native soils and existing aggregate base materials. The crushed and <br /> blended rock material has been placed over the excavated site and wheel-roiled for compaction. The site <br /> appears to be neat and clean. <br /> Third-Quarter 1997 Monitoring Results <br /> Groundwater was flowing S 40' E, with a gradient of 0.0036, on August 20, 1997. Inflow of surface water <br /> from the San Joaquin River apparently controls the flow of shallow ground water at the Port Road No. 8 <br /> facility. The flow direction shifts back and forth with seasonal changes in the River. <br /> N-NO3, N-NH4, and TKN concentrations detected in ground water samples from the site have been low. <br /> Nitrates are essentially absent. Field evidence and analytical data suggest that anaerobic microbial <br /> denitrification is taking place beneath the site, and that molasses-based feed products present in the <br /> subsurface have provided nutrients for the desired microbial activity. <br /> Total Dissolved Solids (TDS) and Specific Conductivity (SC) values observed in ground water samples <br /> collected at the Port Road No. 8 facility appear to be related, at least in part, to the intrusion of connate <br /> waters. Elevated TDS concentrations are the result of the combined effects of dissolved mineral constituents <br /> from connate intrusion and dissolved (non-conducting) organic substances from molasses. Although chloride <br /> levels are very high, the TDS to SC ratios of water samples collected from monitoring well CW-01 have <br /> been twice that which would be expected solely from dissolved mineral constituents (connate intrusion). <br /> This is probably due to the presence of dilute molasses. <br /> (916)933-1468 <br /> 4911 Windplay Drive,Suite 4 EI Dorado Hills,California 95762 (916)933-3197 FAX <br />