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Draft Environmental Impact Report Page IV.F-23 Forward Inc. Landfill Expansion Groundwater contamination at the existing Forward Landfill is limited mainly to wells immediately north of Forward's closed Class I WMU-A that show detectable concentrations of VOCs but otherwise Forward Landfill leachate collection system appears to have integrity. In 1996, a leachate seep was discovered in the north face area of the Austin Road Landfill. Currently the Austin unit well AMW-1 on the northwest side landfill shows the highest groundwater VOC contamination. The following groundwater quality protection measures are proposed as part of the project: • A double liner would be installed under the sump area, as previously required by the RWQCB; • The liner and leachate collection system for the new expansion areas would have new lechate system. This would be articulated in the applicants new JTD. The JTD and the adequacy of the leachate collection system and associated monitoring would be reviewed by the RWQCB; • The regulatory required separation between the liner and groundwater shall be implemented to allow for chemicals in the leachate to attenuate before reaching the groundwater, should the leachate breach the collection system; • Electric testing of the liner in each Waste Management Unit shall be conducted before waste can be disposed in that Unit, as required by the RWQCB; • If any modifications to the leachate collection system and associated monitoring described in the upcoming JTD are required by the RWQCB, the landfill operator shall implement those changes; • The project design will include a leak detection system under the sumps;and, • The liner system will be overlain by a protective operations layer consisting of a one-foot thickness of soil and a one-foot thick gravel layer that serves as the leachate collection layer. This two-foot layer will serve to protect the liner system from sharp or jagged materials in the waste. • The operator will remove any hazardous materials spotted during delivery, thus minimizing the potential for leachate contamination if a break occurs in the liner or the leachate collection system. In addition, the RWQCB will review the updated JTD, the leachate collection system, and associated monitoring, and could require changes to the planned leachate collection system or monitoring. Implementation of these procedures and mitigation measure would reduce the impact to a Iess- than-significant level. Impact F.4 Project activities that increase leachate production from existing landfill materials could result in additional groundwater contamination. More refuse would be generated by the combined project than would be under the existing landfill operating permit so that there is a potential for more leachate to be produced over time. GeoLogic (2008a)estimated up to about 32,000 gallons of leachate a days could be generated. The base liner system design will need to be compliance with the current WDRs for the existing facilities and in accordance with 27 CCR, Section 20330 requirements for a Class II liner system applicable to the Forward Landfill. Forward Inc. is currently in the process of working with the RWQCB to prepare a Liner Performance Demonstration for final determination of the base liner design. The current proposed base liner components are presented in the project description. It