MAPPING SUBSURFACE CAVITIES AND FRACTURES USING INTEGRATED SURFACE AND BOREHOLE GEOPHYSICS NEAR A SUPERFUND SITE SOUTH OF ROCKFORD, ILLINOIS

The ACME Superfund site is one of many Superfund sites in Northern Illinois. This 20 acre (8.1 ha) site was contaminated by various volatile organic compounds (VOC’s) and heavy metals during the 1960-1980s. These contaminants have seeped into the Wise Lake dolomite (Galena Group) and contaminated local ground water supplies. The field site is located immediately south and hydrologically downgradient of the ACME site, where up to 10 m of unconsolidated sediments overlie the fractured and karstic Wise Lake Formation in a small valley adjacent to residential wells.