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MEMO 00 ARCADISbuiltmeto'Su"a"`y fornaturaland • built assets Date: Arcadis Project No: Author: July 3, 2019 SM010309.0011 Shawn Roberts, Senior Geologist Subject: Extraction Well EW-1, EW-2 and EW-4 Hydraulic Testing Technical Memo for Forward Landfill, San Joaquin County, California. On behalf of Forward Inc., Arcadis U.S., Inc. (Arcadis) has prepared this technical memo as part of assessment and optimization of the point of compliance(POC)groundwater treatment system (GWTS)at the Austin Road Unit of the Forward Landfill, San Joaquin County, California(Site). The hydraulic testing activities were conducted on existing extraction wells EW-1, EW-2 and EW-4 at the Site, as shown on Figure 1. The hydraulic testing was conducted to evaluate individual well pumping capacities, assess well specific optimal pumping rates and associated groundwater capture. The work was approved verbally by the Water Board as an added element to the Workplan for Well Installation and Hydraulic Testing at the Forward Landfill, San Joaquin County, California(Arcadis 20181). The work was performed in accordance with the hydraulic testing procedures presented in the Workplan. This summary report presents the data analysis and findings for the hydraulic testing, including well pumping capacities and hydraulic capture. • HYDRAULIC TESTING Well construction details for the pumping and any monitoring wells used are presented in Table 1. For hydraulic testing, the installed submersible pumps were utilized,with discharge routed to the existing groundwater treatment system (GWTS). The pumping rate and total discharge were measured using well totalizers which were positioned in a straight section of pipework to maintain laminar flow conditions. To record water level change in the pumping well, where possible, a pressure transducer was installed in a drop pipe or through the well head and lowered to within 5 feet of the pump,where it would not be affected by turbulent conditions.Water level data was also collected from monitoring wells that were located close to the pumping wells. Periodic manual water levels were collected from all wells before, during and after the hydraulic tests. Before conducting the hydraulic tests, the extraction and monitoring wells were allowed to recover to static conditions after the GWTS was shut down on April 30, 2019. Each extraction well was hydraulically tested individually to prevent well interference and increase the potential for observing pumping influence on adjacent wells. During the tests the gate valves for all wells apart from the pumping well were closed to prevent water entering non-pumping wells and causing recirculation of water.All extracted groundwater was directed to the treatment system. • ' Arcadis 2018,Workplan for Well Installation and Hydraulic Testing at the Forward Landfill, San Joaquin County, California, dated November 16 Page: 1/7