CORRESPONDENCE_2007 (1/07 - 6/07)

Home Browse Search

California 6gional Water Quality Conol Board Central Valley Region Karl E.Longley,ScD,P.E.,Chair (a Linda S.Adams Arnold Sacramento Main Office Secretaryfor 11020 Sun Center Drive 4200,Rancho Cordova,California 95670-6114 Schwarzenegger Environmental Phone(916)464-3291 -FAX(916)4644645 Governor Protection http://www.waterboards.ca.gov/centralvalley 11 April 2007 W. Michael Carroll San Joaquin County Dept. of Public Works t7 C. Solid Waste Division P.O. Box 1810 Stockton, CA 95201 REVIEW OF THE REVISED PLAN TO THE EVALUATION MONITORING PROGRAM WORK PLAN, CORRAL HOLLOW SANITARY LANDFILL, SAN JOAQUIN COUNTY. The Regional Water Quality Control Board (Regional Water Board) staff has reviewed the revised plan to the Evaluation Monitoring Program Work Plan. The revised plan was submitted in response to staffs comments in a letter dated 13 March 2007. Staff approves the revised plan and has the following comments: • To ensure the proposed investigation will maximize the coverage of the limited number of borings, the borings should be drilled on 300-foot centers. Figure 2 of the revised plan indicates the proposed borings HP-7 through HP-9 will be advanced on closer centers. • The Discharger should consider moving Boring HP-9 southwest of GW-6 to collect soil gas and groundwater samples (if possible). • Permanent groundwater monitoring well MW-9 should be placed in the vicinity of boring HP-8. • Cross sections should be constructed using all available subsurface data that shows structural controls such as the Corcoran Clay. The sections should also incorporate other site features such as the western storm water retention pond and how the depth of the pond is positioned relative to the depth of the waste management unit. California Environmental Protection Agency Recycled Paper