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• R,� W REPUBLIC �►� SERVICES Mr. Brendan Kenny Engineering Geologist Central Valley Regional Water Quality Control Board 11020 Sun Center Drive, Suite 200 Rancho Cordova, CA 95670 July 31, 2017 RE: Forward Landfill—2017 Annual Corrective Action Evaluation Report Dear Mr. Kenny: In accordance with Section B.5 of the Monitoring and Reporting Program (M&RP) R5-2014-0006, Forward Incorporated is pleased to present this 2017 Annual Corrective Action Evaluation Report for the Austin Road Unit(ARU)of the Forward Landfill. During the monitoring period, there have been no exceedances of the Total Volatile Organic Compound (TVOC) mass Threshold Limit (TL), and the TVOC mass did not exhibit four consecutive quarters of • increases. However, the median TVOC mass has doubled from 203 kg to 407 kg for the 2017 monitoring year. In addition, there were eight quarterly exceedances of individual well TVOC concentration TLs during the past four quarters: two at shallow detection well AMW-12; four at shallow corrective action well AMW-19; and two at deep corrective action well AMW-19BR. All of the individual well TL exceedances were due to increasing concentrations of tetrachloroethene(PCE). On June 30, 2017, Forward submitted an Interim Groundwater Plume Remediation workplan to the RWQCB to address the TL exceedances in the vicinity of these wells. With the exception of wells AMW-12, AMW-13, AMW-19, and AMW-19BR, overall TVOC concentrations have generally decreased or remained static following implementation of the corrective action measures. However, the VOC concentrations are still higher than the concentrations predicted in the model simulations presented in the 2001 Engineering Feasibility Study. Historically, EMP/CAP wells AMW-1, AMW-22, and AMW-22S continue to exhibit the highest TVOC concentrations downgradient of the ARU. During the monitoring period, one or more VOCs exceeded a State maximum contaminant level in wells AMW-1, AMW-12, AMW-13, domestic well 8106-A, AMW-19, AMW-19BR, AMW-21, AMW-22, AMW- 22S, AMW-26R, and AMW-29. In an effort to define the lateral and vertical limits of the VOC plume, Forward will begin drilling and installing 12 additional EMP/CAP wells downgradient of ARU in August 2017. Forward has also implemented a Domestic Well Sampling Program to evaluate the presence of VOCs in downgradient public wells. The results obtained from the additional EMP/CAP wells, the Domestic Well Sampling Program, the new Point of Compliance Landfill Gas Monitoring Program, along with the existing EMP/CAP wells, will be used to prepare a revised Engineering Feasibility Study that may include revisions to the corrective action program and evaluation procedures previously described in the Evaluation Procedures Report. Forward has also prepared an Interim Groundwater Plume Remediation Workplan to address VOCs downgradient of the ARU. 9999 South Austin Road • Manteca, CA 95336 (209) 235-9622/(209) 982-1009 fax ilipka(aD-republicservices.com