As part of the Feasibility Study, H&H completed natural attenuation treatability testing in accordance with EPA Region 4 natural attenuation guidance for chlorinated solvents, as well as three-dimensional fate & transport modeling in support of a natural attenuation remedial strategy. Site-specific leaching tests were also performed on site soils to identify the soil concentrations that are protective of groundwater. H&H conducted RD and RA planning, and subsequently constructed and operates the first phase of the active remedy, with the second phase of RA in design at this time. The remedy has removed over 2,000 lbs of contaminant from the subsurface and is being expanded to achieve remedial action objectives for the site.
Additional assessment was recently completed to further define the extent of impacts and better understand the bedrock surface. The additional assessment was completed using traditional assessment methods in conjunction with rapid assessment MIP methods. Bedrock assessment was completed by geophysical seismic refraction and EM surveys. This additional assessment data is being utilized to develop a three-dimensional conceptual site model to aid in the second phase of remedial design and construction.