Characterization of a lanfill-derived containment plume in glacial and bedrock aquifers, NE Illinois

Groundwater contamination by organic and inorganic chemicals is a regional and national problem; landfills are major potential contaminant sources. In this study of the Blackwell landfill, DuPage County, Illinois, the contaminant plume is delineated and related to the site history and hydrogeology. Leachate leakage is attributed partly to landfill construction problems. The landfill is located partly on a sand-and-gravel aquifer and partly on thick, poorly permeable till, all overlying an important dolomite aquifer. A roughly concentric contaminant plume surrounds the landfill in the glacial materials. A leachate leakage rate of between 600 and 3000 ft /day was estimated from infiltration and leachate-level calculations. The leakage is rapidly diluted in the aquifer; background TDS levels are reached on site. Volatile organics have concentrations of over 100 ppb in the aquifer close to the landfill, but decrease rapidly away. The contaminant plume appears to have reached equilibrium, and does not extend off site. The bedrock is probably in continuity with the glacial aquifer; however, the traces of organics found therein are not clearly linked to the landfill plume and may originate from other sources. This study has generated considerable field data which should be valuable in future studies.U.S. Department of the InteriorU.S. Geological Surve