Laserfiche WebLink
Geospte& <br /> consultants <br /> o Current biogeochemical conditions at the highest concentration well W-020 to <br /> evaluate the feasibility of monitored natural attenuation (MNA) and in-situ <br /> treatment technologies. <br /> • Site 49 Central Area <br /> o Concentration trends and biogeochemical conditions at the highest concentration <br /> well W-336, which was installed in 2020, to evaluate the feasibility of MNA and <br /> in-situ treatment technologies. <br /> o The southern cross gradient extent of vinyl chloride in groundwater with <br /> concentrations above drinking water screening levels. <br /> • UST 817B Central Area <br /> o Biogeochemical conditions at the highest concentration well 917-10 to evaluate <br /> the feasibility of MNA and in-situ treatment technologies. <br /> o The extent of petroleum hydrocarbons in groundwater west of the former UST. <br /> o The extent of the secondary source remaining in soil. <br /> • Landfill Area <br /> o Completion of the Stockton Soda Bulk Export Terminal rail line construction and <br /> installation and sampling of new groundwater monitoring wells <br /> o Completion of the surface water investigation to determine if COPCs in surface <br /> water exceeding ecological screening levels originate from sediments or <br /> groundwater. <br /> o Completion of the background metals evaluation to determine if metals <br /> concentrations above drinking water screening levels are naturally occurring or <br /> associated with a waste cell. <br /> o The extent of PFAS in groundwater, which is a Navy retained responsibility per <br /> the ESCA. <br /> • Site 3 <br /> o The downgradient extent of the VOC plume. A new downgradient monitoring <br /> well W-338 was installed in 2020 and was non-detect for VOCs for the first two <br /> annual sampling events but had concentrations of VOCs reported above drinking <br /> water screening levels in 2023. <br /> o The vertical extent of the VOC plume. A grab-groundwater sample GGW-25 <br /> from 85-90 feet bgs VOCs were reported at concentrations above the drinking <br /> water screening levels. Per the ESCA the Navy retains responsibility at RRI <br /> below 90 ft bgs. <br /> RRI 2024 Groundwater Monitoring Work Plan 6 June 13,2024 <br />