Geology and evaluation of potential for contamination of the vicinity of the Metropolitan Landfill, Liberty Township, Delaware County, Indiana using earth resistivity as guidance

Abstract

The area immediately surrounding a landfill was studied by DC resistivity methods, soil borings, and review of historical data bases to learn if the landfill had released leachate to the ground water and to define the geology and hydrogeology of the site. Property immediately adjacent to the landfill has been proposed as a new landfill site. The geology and hydrogeology of this site were investigated to provide supplemental data for use in planning and operating the new landfill.Although no contaminant plumes were located by resistivity methods, the range in measured resistivity values proved to be sufficiently large to possibly mask existing leachate migration from the landfill. Using the resistivity data base generated through this effort, future resistivity surveys at this site may identify changes indicating contaminant plume formation or migration.Zones of shallow sand and gravel were found (by resistivity methods) to be present at locations that appear to correlate with slightly higher topography and soil type MuB2. This information led to the location and confirmation of other shallow permeable zones in the glacial drift with the same common attributes (soil type MuB2, higher topography and 5 to 15 feet deep sand and gravel). These shallow permeable zones had been omitted from the ground-water monitoring systems for both the Metropolitan Landfill and the proposed Delaware County Landfill. The results of this study were used as the basis for recommendations presented to the local board of health and the state regarding the need for additional ground-water monitoring at the two sites and the suggested locations for such.