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Mr. Brendan Kenny
<br />Central Valley Regional Water Quality Control Board
<br />April 14, 2023
<br />• On December 17, 2022, GWE well EW -3R was turned off due to a faulty pump. Pump repairs were completed
<br />and the well was restarted on January 30, 2023.
<br />• On March 16, 2023, all GWE wells were turned off to allow water to drain from GAC Unit #1, after which the
<br />carbon in the lead GAC Vessel (GAC Unit #1) was changed out. Following the carbon changeout, the vessel
<br />order was switched so that GAC Unit #2 and GAC #1 were in lead and lag positions, respectively. All GWE
<br />wells were restarted on March 18, 2023.
<br />All five of the active groundwater extraction wells (EW -1, EW -2, EW -3R, EW -4, and EW -5) and the treatment
<br />system were operational throughout the majority of the reporting period, except for brief maintenance activities
<br />and for the shutdowns as described above. Flow rates were continuously monitored and adjusted to increase
<br />groundwater capture with the upgraded treatment system.
<br />Landfill Gas Collection and Control System
<br />During the First Quarter of 2023, the landfill gas collection and control system (GCCS) at the Austin Unit of the
<br />Forward Landfill included 215 active landfill gas extraction wells. The landfill gas collected from these wells is
<br />routed and split between the Ameresco Landfill Gas to Energy Facility (LFGEF) and Forward's Flares A-1 and A-2
<br />for thermal destruction.
<br />The landfill gas extraction wells are monitored semimonthly (twice per month) by SCS Field Services of Modesto,
<br />California (SCS). The SCS semimonthly monitoring results for Point of Compliance wells and individual wells are
<br />included in Tables 1 and 2 of the Quarterly Program Update, which is included as Attachment C. Probes GP -10D,
<br />GP -10M, GP -10S, GP -11 D, GP -11 M, GP -11 S, and GP -12D had exceedances of methane greater than one
<br />percent. In addition, probes GP -1 OD, GP -10M, GP -10S, GP -11 D, GP -11 M, GP -11S and GP -12D had VOC
<br />concentrations above 10 parts per billion (ppb). As required, on October 10, 2022 annual samples were obtained
<br />and analyzed using Environmental Protection Agency Method TO -15. The next annual sampling event will be
<br />performed by the end of November 2023, or as requested by the client. As recorded in Table 1, VOCs were
<br />detected at concentrations ranging from 400 ppb in GP -10M , GP -11 M, and GP -12D to 3,700 ppb in GP -11 D.
<br />The landfill GCCS undergoes periodic maintenance and tuning to produce the highest percentage of landfill gas
<br />and to minimize the collection of oxygen. The general operation of the GCCS during the First Quarter of 2023 is
<br />documented by SCS (Attachment C). During the First Quarter 2023, the instantaneous total flow rate was
<br />measured at the site and included both LFG flares and the Ameresco LFGTE Facility. The instantaneous total
<br />flow rate of LFG on March 17, 2023, was 1,402 standard cubic feet per minute (scfm) at the LFGEF facility, 1,510
<br />scfm at Flare A-1 (New Flare), and 1,510 scfm at Flare A-2 (Old Flare). SCS documented there was no significant
<br />downtime during the First Quarter of 2023.
<br />Residential Treatment Systems
<br />Forward, Inc. has been monitoring domestic drinking water wells in the vicinity of the landfill since 2017 as part of
<br />the domestic well monitoring program. Also, some owners of private wells have been receiving bottled water as a
<br />result of low VOC detections for several years. During the First Quarter of 2023, Forward, Inc. continued to
<br />provide operation, monitoring and maintenance for 14 residential water treatment systems on Austin and
<br />Newcastle Roads.
<br />The treatment systems are composed of inline sediment filters and dual GAC canisters that remove VOCs from
<br />the water prior to entering the residence. Regular system sampling and maintenance on the treatment systems is
<br />performed by Del -Tech to ensure that VOCs do not enter the water supply. Systems offers were declined by two
<br />www.arcadis.com 3/4
<br />Forward Landfill 1Q23 CAP Rpt 04142023
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