Remediation Solution
Remediation Approach
Technology
Media Treated
Industry
Contaminant Type
Contaminant of Concern
Location
Hexavalent chromium contamination averaged 11,700 ppb across a 48,127 ft² plume in shallow groundwater (6–10 ft depth), with historical concentrations ranging from 3,750 to 44,600 ppb in MW-7R. Two distinct source areas were identified, and equipment staging and injection activities were required to be conducted inside an occupied industrial facility.
A sodium dithionite and ferrous sulfate reduction solution was injected at 250 gallons per well into 18 drilled injection wells (4,500 gallons total), staged and operated from inside the facility. Treatment was concentrated around the two identified source areas within the defined plume footprint.
Two-year post-treatment monitoring confirmed an 89% reduction in total hexavalent chromium concentrations across the 48,127 ft² plume, with a 44% decrease in the area exceeding the 100 ppb threshold. The sodium dithionite and ferrous sulfate injection program—conducted entirely from inside the occupied industrial facility using 18 drilled wells at 250 gallons per well—addressed both identified source areas within the defined plume footprint. Rebound observed in MW-7R following treatment identified previously uncharacterized hotspots within the plume, providing site-specific data to inform the design of targeted follow-on treatment phases.
Superfund ISTR Under Strict Air Emission Limits
Bioremediation for PFAS
High-Profile ISTR of Historic Chemical Disposal Impacts
