J&S Chrome Plating and Former Chrome Crankshaft Company Sites

The project involved soil and ground water contamination from operation at two contiguous sites, the J&S Chrome Plating facility and the Chrome Crankshaft Company facility. The Sites operated as metal processing and plating facilities. The manufacturing process at the Sites consisted of chrome, zinc and cadmium plating of metal. Solvent degreasing operations were also performed using napthylene, methyl ethyl ketone, trichloroethylene, tetrachloroethylene, & 1,1,1-trichloroethane. DTSC initiated the Sites investigation and cleanup in 1999. The investigation revealed that hexavalent chromium was present in soil and groundwater at the Sites. NEC Group, as the DTSC contractor, conducted numerous remedial activities at the Sites. The Sites was divided into two operable units (OUs). OU-1 encompasses soil at the Sites and OU-2 encompasses groundwater at the Sites. NEC assisted in the construction, operation and maintenance of the OU-1 in-situ treatment system for the Sites which encompassed the construction, operation and maintenance of subsurface infiltration galleries and the injection of calcium polysulfide (CPS) within the vadose zone in

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order to neutralize hexavalent chromium present in the Sites soils. Subsequently an in-situ groundwater remediation system was designed to remediate OU-2 hexavalent chromium impacted groundwater underneath and downgradient from the Sites. The remediation system includes the on-site treatment of residual hexavalent chromium in soil within the vadose zone using CPS. CPS is infiltrated via on-site infiltration galleries; on-site treatment of groundwater using an active (i.e., able to be replenished) reactive CPS barrier located along the western boundary of OU-2; hydraulic containment of the hexavalent chromium plume using extraction wells located along the southwest boundary of OU-2; treatment of downgradient groundwater with CPS using an active reactive barrier in the eastern portion of a nearby Park; in-situ treatment of elevated Hexavalent Chromium concentrations in groundwater via one-time injection of CPS at the northeast and central portions of the nearby Park; treatment of downgradient groundwater with CPS using an active reactive barrier at a nearby Road; treatment of downgradient groundwater with CPS using an active reactive barrier at a nearby alleyway east of

The Sites; and treatment of downgradient groundwater with CPS using a passive (i.e., established by a single injection event) reactive barrier at the leading edge of the OU-2 plume. This large and robust in situ groundwater remediation system is currently being conducted by NEC Group. NEC is currently in the process of developing new and innovative methods to deliver CPS solution to remaining impacted groundwater in light of the drop of groundwater elevation levels due to the Southern California drought.