Laserfiche WebLink
California Regional Water Quality Control Board <br /> Central Valley Region <br /> Robert Schneider,Chair <br /> Winston H.Hickox Gray Davis <br /> SecEnvironmor <br /> ental <br /> Sacramento Main Office Governor <br /> Enrotectertlal Internet Address: http://www.swrcb.ca.govl—gcb5 0 r(�- /j�t���� ED <br /> Protection 3443 Routier Road,Suite A,Sacramento,Califomia 95827-3003 Ipfl<l I`r1��- IIV_IL,`�- V�LL��. <br /> Phone(916)255-3000•FAX(916)255-3052 <br /> 13 August 2002 AUG 15 2002 <br /> ENVIRONMENT HEALTH <br /> Ms. Julie RainingPERMIT/SERVICES <br /> Environmental Affairs <br /> Georgia-Pacific Corporation <br /> P.O. Box 105605 <br /> Atlanta, GA. 30348 <br /> WELL ABANDONMENTAND MONITORING WELL INSTALLATIONREPORT, FORMER <br /> GEORGIA-PACIFIC CORPORA TON TRACY CHEMICAL PACKAGING PLANT, 75 WEST <br /> VALPICO ROAD, TRACY, SANJOAQUIN COUNTY <br /> We have reviewed the 30 July 2002 Well Abandonment and Monitoring Well Installation Report, <br /> Former Georgia-Pacific Corporation Tracy Chemical Packaging Plant, 75 West Valpico Road, Tracy, <br /> San Joaquin County(Report). <br /> The Report describes the abandonment of monitoring wells BC-1, BC-12, and recovery well RW-1. <br /> Drilling, development, and sampling activities associated with the installation of monitoring well,MW- <br /> 21 were also summarized. MW-21, screened in sand Unit 2,was installed 100 feet upgradient of the <br /> stormwater basin, long considered to be the source of chloroform pollution to groundwater, to provide <br /> further definition of the chloroform plume. The highest chloroform concentrations have historically been <br /> detected in this stratagraphic layer. The well was sampled twice following installation and development. <br /> Laboratory analysis of the two groundwater samples obtained from MW-21 indicated the presence of <br /> chloroform at concentrations of 46 pg/L and 29 µg/L. The California/Environmental Protection Agency <br /> (Cal/EPA)cancer potency factor for chloroform is 1.1 µg/L. Based on the findings, it was recommended <br /> that remedial activities should be delayed until additional site characterization is performed. Our <br /> comments on the Report are presented below. <br /> General Comments <br /> 1. Based on the descriptions provided in the Report, the abandonments of groundwater wells BC-1, <br /> BC-12, RW-1, and the two MW-21 boreholes were adequately accomplished. <br /> 2. The chloroform presents evidence of additional groundwater impacts upgradient of the stormwater <br /> basin. These detections,however, are minor compared to historical chloroform concentrations of <br /> 15,000 µg/L detected in groundwater samples obtained from source area monitoring well BC-2. <br /> Additionally, chloroform was detected in monitoring well BC-6, located approximately 1,400 feet <br /> upgradient from the source area, in earlier sampling events. The distribution of chloroform in <br /> groundwater at the plant indicates that chloroform pollution to ground water may have resulted from <br /> California Environmental Protection Agency <br /> 0 Recycled Paper <br /> The energy challenge facing California is real. Every Californian needs to take immediate action to reduce energy consumption. <br /> For a list of simple ways you can reduce demand and cut your energy costs,see our Web-site at http://www.sweb.ca.gov/mqcb5 <br />