INITIAL GEOMATERIALS INVESTIGATIONS OF A RESTORED PRAIRIE ON LANDFILL COVER AT THE MIAMI UNIVERSITY HAMILTON CAMPUS

Hamilton, Ohio is representative of typical post-industrial Midwestern cities that have extensive environmental issues and have a legacy of problems of which minimal resources are available to address. Miami University Hamilton is an environmentally unusual campus as many areas are constructed on a closed landfill. This landfill received solid waste including large amounts of coal ash for decades. The topography of parts of the campus is dominated by cell features. Several recovered natural areas are managed on campus and include a tallgrass prairie that was installed in the early 2000’s and forested areas. The tallgrass prairie is approximately 30 m x 110 m and provides an opportunity to investigate natural restoration approaches. Little is known regarding the mineralogy, geochemistry and extent of pollution in restored tallgrass prairie soils on landfill covers. Agricultural data indicates that magnesium varies from approximately 300 to 450 kg/ha, phosphorous varies from approximately 25 to 130 kg/ha, and potassium varies from approximately 200 to 500 kg/ha. Preliminary investigations indicate that moisture content varies from 1.6 to 39.0 wt% and organic content varies from 3.1 to 9.6 wt % and thus are highly variable. Scanning electron microscopy indicates that the dominant non-clay minerals present are quartz, dolomite, iron oxides and plagioclase. Quartz grains are rounded as are iron oxides. Iron oxides commonly have appreciable Ti content. Plagioclase grains are subhedral. Quartz, iron oxides and plagioclase have textures that are detrital and may be locally derived from glacial material. Dolomite occurs in angular lithic clasts of dolostone up to 1.5 cm in diameter. Dolomite is interpreted as being anthropogenically introduced aggregate as the nearest sources are approximately 60 kilometers away. Lead – tin alloy particles were observed in one sample and suggest metal particulate persists in the soils. The lead – tin alloy particles show a complex intergrowth with textures that suggest phase separation. The prairie soils offer an opportunity to compare environmental remediation strategies with other on campus and off campus approaches.