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

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Forward Landfill - 2 - 3 August 2017 San Joaquin County 19, AMW-22s and proposed monitoring well AMW-23s to monitor aquifer response during the pump test. The Workplan proposes to pipe extracted water generated from the wells to a modular groundwater treatment system consisting of granular activated carbon vessels prior to discharge/disposal into the recharge basin. Installation of the extraction wells and performing the pump test and is anticipated to be completed in the Fall of 2017. STAFF COMMENTS: Staff question if the extraction of groundwater from two proposed wells will be sufficient to comply with the CAO, which requires the pumping wells to create an inward gradient for the purpose of controlling the expansion of the plume. Historical monitoring of the existing Extraction Wells EW-1 through EW-4 have a combined groundwater pumping rate of approximately 200 gallons per minute. This extraction rate has been ineffective in controlling the release. Therefore, Forward Landfill must select a pumping rate greater than 200 gallons a minute. Forward landfill may want to evaluate the use of a groundwater model to aid in selecting the correct initial pumping rate, with the understanding that if an inward gradient cannot be achieved, and physically measured, then a higher pumping rate along with additional extraction wells would be necessary to comply with the CAO. Forward has recently identified domestic wells located west of Newcastle Road, which are screened in excess of 250 feet below ground surface, and have been impacted by VOCs associated with the release of waste from the landfill. It is the expectation of the Board, as well as required by Title 27 that all zones, affected by the release, have remedial action occurring. Therefore, Forward should re-evaluate the need for a deeper extraction well(s) in the vicinity of the impacted domestic wells to comply the CAO. Staff note that the proposed monitoring system of pressure transducers to document aquifer response is not adequate monitor aquifer response in the zone currently monitored by AMW-22 and/or to demonstrate the inward gradient at monitoring wells within the known extent of the plume as required by the CAO. Therefore, during the proposed pump test, water levels in Monitoring Wells AMW-22, AMW-23, AMW-25/25s, AMW-28/28s and AMW-30/30s shall be recorded to document aquifer response in all groundwater zones currently monitored and at the distal portions of the plume. With regard to the proposed discharge of extracted/treated groundwater to the existing recharge basin, which is regulated by WDRs R5-2003-0080. The discharge is permissible as long as the extracted groundwater meets the effluent limits in the WDRs and there is adequate capacity in the basin. To evaluate compliance with WDR R5-2003-0080, a water balance must be submitted to determine if additional storage/disposal capacity will be needed to account for the increased flows. Staff will approve the plan with the following conditions. Please review the conditions below and submit a statement accepting the conditions, no later than 15 August 2017. CONDITIONS OF APPROVAL: • Provide an evaluation of the proposed construction of EW-5, the site lithology and rational for either maintaining or modifying the proposed screen interval to address VOCs which have recently been identified at depths in excess of 250 feet below ground surface. Alternatively, additional extraction wells may be proposed.