COMPLIANCE INFO_EW-5 INSTALL PERMIT PACKAGE 2/14/25

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Forward Landfill - 2 - 27 December 2018 • The screen interval of each groundwater monitoring well should not exceed 20 feet and the bottom of the well must be plugged or capped to prevent sediment or rock from entering the well. • Per the San Joaquin County Well Standards, the filter pack should be surged, and the elevation of the filter pack verified prior to the installation of the transition seal. • Well development must continue until monitoring parameters (pH, E.C., temperature, turbidity) have stabilized and turbidity is below 5 ntu. • Upon completion of the monitoring wells, the wells must be surveyed by a California licensed surveyor. All wells shall be surveyed using North American Vertical Datum of 1988 (NAVD 88). • A Monitoring Well Installation Report shall be submitted, and the boring logs shall be uploaded to Geotracker following completion of the wells. The Report shall contain the items in the attached document titled in Requirements for Monitoring Well Installation Reports. Please note that the report shall also include a geologic cross section incorporating the newly installed wells along the Point of Compliance of the Austin Road Unit. Hydraulic/Aquifer Testing • To ensure that the extraction wells are functioning as designed, prior to implementing the test, the screen interval of the extraction wells should be assessed to determine the extent of biofouling/blockages and re-developed (if necessary). • The Workplan proposes to monitor water levels during the pump test in several of the existing monitoring wells at the facility. Of the wells listed in the workplan, extraction well EW-3 and monitoring well AMW-9 may have been previously destroyed. Please confirm the location and condition of wells EW-3 and AMW-9. • The Workplan states that water levels will be monitored in pumping wells, monitoring wells, and background wells for a minimum of 24 hours prior to the start of hydraulic testing to establish regional water level trends. Board staff note that an agricultural supply well is located approximately 600 feet west of Extraction Well EW-3R. The construction details of the supply well should be reviewed and the pumping rate and run time for this well (and any other supply wells in the vicinity) should be evaluated and discussed in the final Aquifer Testing Summary Report. • The Workplan states that the constant rate pump test will continue for up to 24 hours. The test should run for no less than 24 hours and should continue until equilibrium is approached to ensure that the data set acquired during the proposed pump test is adequate to accurately characterize aquifer conditions. Please understand that the performance of the pumping system is outlined in Item 3c of the CAO. The pump test should be followed by a similar duration/period of active well recovery monitoring. • The Workplan states that all extracted groundwater generated during the proposed pump test will be discharged to the site’s existing groundwater treatment system (GWTS). If the existing GWTS is inadequately sized for the volume of extracted water,