HEAVY METAL CONCENTRATIONS AND ENVIRONMENTAL MINERALOGY OF STREET SEDIMENT IN A COMMUNITY NEAR A COAL PLANT IN HAMILTON, OHIO

The Hamilton Municipal Electric Plant is a coal-burning power plant that is currently operating in the city of Hamilton in the lower portion of the Great Miami River Basin in southwest Ohio. Hamilton is an economically disadvantaged community with numerous environmental issues. A community of 53 homes lies between the coal plant and the Great Miami River. Street sediment samples were taken in the small community of homes and also along a bridge crossing the river to assess if appreciable concentrations of priority pollutant metals exist.

Average moisture content constitutes approximately 3% of total sample mass, organic matter constitutes approximately 10% of total sample mass mass, and the remaining solid content is approximately 88% of total sample mass. Munsell color of the street sediment was dominantly 10YR 4/1. XRD analysis revealed street sediment is composed of primarily of quartz, dolomite, calcite, and kaolinite.

This study followed the methodology for the U.S. EPA’s priority pollutant metals (EPA 7471B for Hg, EPA 6010C for other metals). ICP-MS was conducted to determine heavy metal concentrations in the sediment samples. ICP-MS analysis reveals street sediment from the community of homes adjacent to the coal plant contains an average of 25 ppm Cr, 40 ppm Cu, 15 ppm Ni, 215 ppm Pb, and 500 ppm Zn. Pb and Zn had maximum concentrations of 1207 and 1512, respectively. Moderate correlation was found between nickel and chromium, nickel and copper, and zinc and lead (R2=0.6541, R2=0.35483, and R2=0.4619, respectively). Copper and nickel each correlate well with total organic matter (R2=0.60483 and R=0.60915, respectively).

Scanning electron microscopy (SEM) indicates heavy metals occur as discrete submicrometer particles and that barite was abundant in some samples. SEM confirms the presence of calcite, dolomite and quartz in samples.

Heavy metal pollution is a major environmental concern, especially when this pollution occurs in an urban neighborhood setting. Potential impacts include a wide variety of health problems associated with ingestion of these heavy metals, as many are toxic to humans. Other potential impacts include bioaccumulation and economic effects like decreased home value. This is the first such environmental study in Hamilton and may serve as baseline information for community improvement.