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Forward Landfill Hydraulic Testing Technical Memo • July 03, 2019 The optimal pumping rate was used for the well capture assessment for each of the wells, with results presented in Table 6. The results indicate that the POC does not have full groundwater capture and that some gaps in capture exist along the POC, however, the eastern portion of the POC is complicated by localized groundwater mounding created by the GWTS infiltration system which alters groundwater flow locally and likely creates a groundwater gradient towards the site in this area. The capture estimates presented are conservative as the hydraulic gradient is likely less than that used for the capture calculations and actual groundwater capture is likely greater in the eastern portion of the POC. GROUNDWATER SAMPLING AND WATER QUALITY MEASUREMENTS Groundwater sampling of extraction wells EW-1, EW-2 and EW-4 were conducted on February 27 and 28, 2019 during the step test towards the start(near the end of Step-1)and end(near the end of Step-2) of pumping. The samples were placed on ice and submitted to BC Laboratories Inc. in Bakersfield, California for analysis of volatile organic compounds(VOCs) by United States Environmental Protection Agency(EPA) Method 8260B. Field parameters were collected with a Hanna multimeter. The water quality parameters for pH, temperature, and electrical conductivity were similar during the pumping tests for extraction wells EW-1 and EW-4(eastern side of the POC), however for EW-4(western side POC) over the course of the step test the electrical conductivity increased (485 to 608 micro siemens per centimeter[NS/cm])and pH decreased (7.18 to 6.95) pumping period(end of step 1 to end of step 5). Two VOC samples per well were collected during the step pumping tests. A summary of the detected . VOCs is presented in Table 7. VOCs were not detected in extraction wells EW-1 or EW-4 located on the eastern portion of the POC. Five VOCs were detected in extraction well EW-2 and seven VOCs were detected in extraction well EW-3R(tested in February)on the western portion of the POC; none were detected above MCL concentrations. DEVIATIONS TO WORKPLAN The following were deviations to the workplan: A pressure transducer could not be deployed to groundwater extraction well EW-4, due to the orifice hole being too narrow. In this case, only manual water level readings were collected from the pumping well. INVESTIGATION DERIVED WASTE Groundwater generated as part of the hydraulic testing activities was routed directly into the on-site GWTS infrastructure. SUMMARY Hydraulic step testing of extraction wells EW-1, EW-2 and EW-4 was performed to assess the respective well capacities, optimize the well extraction rates and assess groundwater capture at the POC. Hydraulic step testing conducted on extraction well EW-1 was pumped up to an extraction rate of 75 gpm which did not stress the well or aquifer capacities and indicated pumping rates of 90-140 gpm could be arcadis com FL Specific Capacity Test Memo 07032019.docx Page: 5/7