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California Regfnal Water Quality Control Board j: -= Central Valley Region M Winston H.Hickox Sacramento Main Office Cray Davis Secretaryfor Internet Address: http://www.swrcb.ca.gov/— gcb5 Governor Environmental 3443 Routier Road,Suite A,Sacramento,California 95827-3003 Protection Phone(916)255-3000•FAX(916)255-3015 13 December 2000 Ms. Julie Raining Environmental Affairs Georgia-Pacific Corporation P.O. Box 105605 Atlanta, GA 30348 REVIEW OF THE MONITORING WELL REHABILITATION REPORT, FORMER GEORGIA-PACIFIC CHEMICAL PACKAGING PLANT, TRACY, SAN JOAQUIN COUNTY We have reviewed the 25 October 2000 Results of Monitoring Well Location and Redevelopment Work, Work Plan for Destruction of Monitoring Well BC-11 (report) submitted•by Brown and Caldwell (BC) on behalf of Georgia-Pacific for the former chemical packaging plant in Tracy. This report summarizes monitoring well inspection and rehabilitation activities, and provides a work plan to abandon well BC- 11. During a site visit in 1994, a BC field technician noted that well BC-11's protective steel casing had been removed and the PVC casing was damaged to 14 inches below ground surface (bgs). In 1995, dredging spoils from the adjacent irrigation canal buried wells BC-9 and BC-10. BC submitted a work plan on 4 February 2000 to perform the well inspection and rehabilitation, which we approved in our 21 April 2000 letter. BC uncovered wells BC-9 and BC-10 to inspect the condition and determined if rehabilitation or replacement is needed. The report states that these wells were generally in good condition, with the surface completions in intact. Redevelopment of BC-9 was not possible because only 0.25 feet of standing water resided in the well. BC stated that redevelopment and sampling of BC-9 would occur if and when a minimum of one foot of standing water is measured in the well. BC found sufficient standing water in BC-10, so BC collected samples from the well for analysis. Groundwater samples collected from BC-10 contained trichlorofluoromethane at 1.3 µg/l and chloroform at 20 µg/1. The reports also states, "Because well BC-10 contained sufficient water, appeared to be in good condition, and produced clear water during sampling, it was not redeveloped." BC should compare the total depth noted in the well construction log and the measured total depth to determine if significant siltation has occurred and if redevelopment is necessary. This evaluation should be included in the first semi-annual 2001 groundwater monitoring report due by 30 April 2001. The report also includes a work plan to abandon well BC-11,which is irreparably damaged. Significant amounts of dirt and debris accumulated in the well, so standing groundwater is no longer present. BC proposes to overdrill the well and pump neat cement into the boring using a tremie pipe. The work plan also proposes to spread soil derived from overdrilling the well on the adjacent property owned by the City of Tracy,providing the City will allow this action. Well abandonment needs to be completed in accordance to San Joaquin County and California Department of Water Resources Well Abandonment Standards. California Environmental Protection Agency p�a Recycled Paper