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CDCR and DGS - 2 - 16 September 2025 In 2017, the Central Valley Water Board issued the 2017 CAO to the Landfill to protect public health, implement interim corrective action measures to prevent further migration of groundwater plume(s) comprised of volatile organic compounds (VOCs) and inorganics, and implement corrective action to restore all beneficial uses of the impacted aquifer zones. Forward Inc. has implemented corrective actions at the Landfill itself. However, a review of the Landfill's groundwater monitoring data' indicates that the groundwater plume continues to migrate north and northeast from the Landfill, extending off-site and beneath portions of the CDCR Facilities. GeoTracker is a website maintained by the State Water Resources Control Board to host environmental data from sites, including the Landfill, across the state2. A review of the groundwater data available on the Landfill's GeoTracker account shows that monitoring wells located upgradient of the CDCR Facilities, and installed in both the shallow and intermediate aquifer zones at the Landfill boundary (wells AMW-13, AMW- 13B, AMW-21, AMW-21S, AMW-31, AMW-31S, AMW-44, AMW-45, and AMW-46) show that the ongoing release from the Landfill has impacted the beneficial uses of the aquifer downgradient of the Landfill. Moreover, data collected from groundwater monitoring well AMW-22S3, which is screened in the shallow aquifer zone and centrally located at the CDCR Facilities, identified the presence of two distinct VOCs at concentrations much greater than concentrations found at the Landfill. The two distinct VOCs — carbon tetrachloride and chloroform4 — detected in AMW-22S from 2014 to 2025 have historically not been detected in groundwater monitoring wells immediately upgradient of the CDCR Facility and only periodically at the Landfill at concentrations more than an order of magnitude lower than concentrations observed at the CDCR Facility. Data during the time frame of 2014 to 2025 shows carbon tetrachloride in groundwater samples collected from groundwater monitoring well AMW-22S at a maximum concentration of 92 ppb. Similarly, data during that same timeframe shows chloroform detected in groundwater samples collected from groundwater monitoring well AMW-22S at a maximum concentration of 37 ppb. The maximum contaminant levels (MCLS) for carbon tetrachloride and chloroform are 0.5 ppb and 80 ppb, respectively. Chloroform can be a degradation byproduct of carbon tetrachloride. Between May 2022 and May 2025 the Landfill installed several groundwater monitoring wells and extraction wells at the CDCR Facilities. A sample collected from groundwater ' https://-qeotracker.waterboards.ca.gov/profile report?global id=L10008827999 (see quarterly groundwater sampling reports from 1Q2017 through 4Q2024) 2 httos://aeotracker.waterboards.ca.gov/profile report?qlobal id=L10008827999 (see quarterly groundwater monitoring reports from 4Q2020 through 2Q2025) 3 https://geotracker.waterboards.ca.gov/profile report?qlobal id=L10008827999 (see quarterly groundwater monitoring reports from 3Q2014 through 2Q2025) 4 Carbon tetrachloride is a suspected human carcinogen and is a hepatoxin. Chloroform is a human carcinogen, a hepatoxin, and a nephrotoxin.