Laserfiche WebLink
California Tonal Water Quality Cont Board <br />4-114"ta <br />Central Valley Region <br />Linda S. Adams <br />Secretary for Sacramento Main Office <br />Environmental 11020 Sun Center Drive #200, Rancho Cordova, California 95670-6114 <br />Protection Phone (916) 464-3291 • FAX (916) 464-4645 <br />http://www.waterboards.ca.gov/centralvalley <br />15 December 2006 <br />W. Michael Carroll, P.E <br />County of San Joaquin <br />Department of Public Works <br />P.O. Box 1810 <br />Stockton, CA 95201 <br />(a <br />Arnold <br />Schwarzenegger <br />Governor <br />FIRST SEMESTER 2006 GROUNDWATER D SURFACE <br />REPORT, NORTH COUNTY RECYCLING CENTER AND SANITARY LANDFILL, SAN <br />JOAQUIN COUNTY <br />Regional Water Quality Control Board (Regional Water Board) staff has reviewed the First <br />Semester 2006 Groundwater and Surface Water Monitoring Report for the North County <br />Recycling Center and Sanitary Landfill submitted on 31 July 2006. The report was prepared in <br />accordance with Monitoring and Reporting Program (MRP) No. R5-2002-0219. The report is <br />complete and satisfies the conditions of the MRP R5-2002-0219 and the Standard Provisions <br />and Reporting Requirements. <br />However, staff has concerns with the soil gas data presented in Table 6 of the report. <br />Methane was detected at a concentration of 50.3% in well SG -6, and multiple VOC <br />compounds were detected in wells SG -2 through SG -8 at concentrations ranging between 2.2 <br />and 1,345 ppb. Based on the analytical data, the vadose zone has been impacted by landfill <br />gas and the current corrective action (LFG system) is not controlling landfill gas migration. <br />One VOC (ethanol) was detected in groundwater wells G-5 and G-6 during the 1St Quarter <br />2006 sampling event. This could be an early indication that VOCs are beginning to partition <br />from vapor phase into the liquid phase, thus impacting groundwater. VOCs were not detected <br />in any groundwater samples during the 2nd Quarter 2006 sampling event. <br />By 15 January 2007, please submit a gas extraction enhancement report. This report shall <br />explain the steps to improve the gas extraction system to contain the landfill gas within the <br />unit. The report should describe a monitoring plan to determine if the changes are effective, <br />and an implementation schedule for each phase of the system enhancement and monitoring. <br />The gas extraction improvement schedule should be expedited to prevent further and future <br />degradation of groundwater. <br />Enclosed is a Monitoring Report Compliance Checklist for your consideration. <br />CIWQS VID#446764 <br />California Environmental Protection Agency <br />�a Recycled Paper <br />