Beneficial Use of Sediments in Soil Blends to Cap and Remediate Contaminated Urban Soils.

Sediments dredged from waterways have been beneficially reused for a variety of purposes, including restoring or creating habitats for wildlife and reapplication on agricultural lands.  Potentially large portions of urban areas contain soil contaminants of concern, such as Pb and PAHs.  Sediments may also contain contaminants as well, particularly PAHs.  This project used a novel combination of soil blends to reduce contaminant levels in both contaminated sediments and the contaminated urban soils.  Including sediments within soil blends provides one method to cap these areas, providing new growing media and reducing public exposure to soil contaminants.  Additionally, reusing the sediments provides a method to reduce storage in confined disposal facilities and reduce open lake disposal.  This presentation summarizes research conducted using sediments collected from Lake Erie to cap urban soils with contaminants above current regularly levels of concern, including Pb levels of 800 - 2,000 mg Pb kg^-1 soil and 3-10 mg benzo(a)pyrene kg^-1 soil.  This study included interviews evaluating regulatory and public acceptance for using sediments in this manner.  Post-treatment soils were evaluated for reductions in Pb in-vitro bioaccessibility (IVBA) using USEPA method 1340 and the modified physiologically-based extraction test (PBET) (Attanayake et al., 2014).  Soils were evaluated for PAH degradation using USEPA method 3545 and accelerated solvent extraction (Dionex ASE 200).  This study provides a combination of treatment evaluation and public acceptance for land application of sediments.