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H. Project Description Groundwater monitoring for the Austin Road Landfill Facility Expansion is required by and would be in accordance with Section 255(b)of California Code of Regulations,Title 23, Division 3, Chapter 15. The monitoring network would consist of background monitoring wells and,downgradient monitoring wells. The expanded landfill would require additional monitoring wells. Use of previously drilled background and monitoring wells would continue. Up to seven new monitoring wells would be added. The new wells would be installed prior to operation of Phase I of the expansion area. The new wells would be finished in the same aquifer currently monitored. The exact location of the wells would be done under the guidance of a hydrogeologist. A program similar to the groundwater monitoring program described above has been submitted to the RWQCB to comply with recent regulations. The program has not yet been approved by the RWQCB. CorrectiveAction Plan. The City has implemented a Corrective Action clan(CAP)dated August 1991,prepared by EMCON Associates(EMCON)and approved by the RWQCB. The CAP includes the installation of an extraction and treatment system to mitigate groundwater impacts to address detected chlorinated hydrocarbon impacts in the first encountered groundwater beneath the Austin Road Landfill. The existing landfill is unlined. Installation of the CAP is expected to begin July 1993 and finish by October 1993. The system will operate until the constituents of concern are no longer impacting groundwater. This could potentially take 30 years or more. The plan includes the use of three motors to run the pumps,blowers,and fans to treat the contaminated water. The installation and operation of the CAP is separate from this project. It will occur with or without the proposed landfill expansion. Surface Water Monitoring. The RWQCB has required monitoring samples to be collected quarterly from the Creek and analyzed. Little Johns Creek would be sampled upstream and downstream of the landfill facility;to determine whether concentrations of indicator parameters or waste constituents at thesepointsof compliance exceed the established water quality protection standards. Surface water samples would be collected and analyzed on a quarterly basis. Leak Detection System. The recommended design includes a leak detection system of secondary collection trenches(collection lysimeters)running below the liner barrier layer parallel to the leachate collection pipe network. Collection lysimeters would drain to a low point beneath the low point of the landfill liner to a leak detection standpipe(sampling station). A portable pump II.32