Laserfiche WebLink
• Quarterly and annual reports of the monitoring results are submitted to the LEA, <br /> DTSC, and RWQCB. The leachate monitoring program consists of daily <br /> inspections of the LCRS sumps for the presence of leachate, with the exception of <br /> WMU A which is inspected semiannually in accordance with DTSC and USEPA <br /> post-closure permits. If leachate is present, the sumps are pumped and the <br /> leachate is disposed (see discussion in Section 7.1.1). Leachate detected in a <br /> previously dry sump is sampled immediately and sampling continues semi-annually <br /> thereafter. Leachate samples obtained are analyzed for the constituents and <br /> parameters listed in the site's WDRs. The quantity of leachate pumped from each <br /> sump is also measured and reported to the RWQCB in gallons per month. <br /> The LCRSs are tested annually to demonstrate operation in conformance with the <br /> WDRs. The results of these tests are reported to the RWQCB and include <br /> comparison with earlier tests made under comparable conditions. <br /> A leak detection system is also located under the sumps (vadose zone) in the <br /> WMUs. The leak detection system consists of either porous suction cup or pan <br /> lysimeters. <br /> • The lysimeters are sampled and tested in accordance with the site's WDRs. Four <br /> VOCs were detected above practical quantitation limits (PQL) in lysimeter samples <br /> in 1999. Two of these constituents (methyl chloride and acetone) are, however, <br /> common laboratory contaminants. No VOCs were detected above PQLs in <br /> lysimeter samples during 2000. <br /> 7.2 GROUNDWATER <br /> 7.2.1 GROUNDWATER PROTECTION <br /> The main mechanism for groundwater protection from leachate generated within <br /> active WMUs is the incorporation of an effective liner and LCRS. Recent studies <br /> by the U.S. EPA (GeoSyntec, 1999) have shown that composite liners and LCRSs <br /> are over 99 percent effective in preventing leachate leakage from WMUs. <br /> The majority of the WMUs at the existing Forward Landfill contain compacted clay <br /> or composite (clay and HDPE geomembrane) liners. There is no liner on the base <br /> • of the existing Austin Road Landfill. Future WMUs at the Forward Landfill will be <br /> constructed with a lining system under the LCRS consisting of a minimum 2-foot <br /> Forward Landfill JTD 7-3 <br /> L:\Allied\2000.193\Reports\]d:Sec-7.0:05/24/02 <br /> BRYAN A.STIRRAT S ASSOCIATES <br />