Siting monofills for residuals using GIS: GIS modeling is a useful screening tool for water utilities that plan to establish monofills

A geographic information system model was developed to locate monofill construction sites for drinking water treatment residuals. Suitability was defined primarily by a site's capacity to prevent leaching of constituents of the residual to groundwater. The model considered land use, topography, bedrock geology, soils, and state regulatory criteria. Adsorption experiments were conducted using cadmium as a representative pollutant to assess the ability of the soils to limit treatment residual migration. Applied in southeastern Pennsylvania, the methodology identified only 6.37 sq mi (16.5 km²), 2.1 percent of the area screened, as suitable for monofills. The major strength of this model is the quick elimination of parcels that fail to meet regulatory or groundwater protection standards. Because it identifies sites that afford the greatest environmental protection, the model is also a valuable aid in winning public acceptance of disposal facilities.