BIO
Bill Frederick has been working in the hazardous, toxic, and radioactive waste (HTRW) field for 21 years. He has both private and public sector experience as a hydrogeologist with Dames & Moore (then URS) and the U.S. Army Corps of Engineers. Bill currently is a lead hydrogeologist with the Corps and a Licensed Professional Geologist in Pennsylvania. He guides groundwater and soil remediation projects for the Buffalo District, as well as several remediation programs under the DOE and EPA.
ABSTRACT
Between 1948 and 1952, up to 15,875 metric tons (35 million pounds) of natural uranium metal (U) were processed at the former Guterl Specialty Steel Corporation site in Lockport, New York. The resulting dust, thermal scale, mill shavings and associated land disposal contaminated both the facility and on-site soils. Uranium subsequently impacted groundwater and a fully developed plume exists below the site. Site soils are composed of anthropogenic fill and re-worked, glacially derived native soil. This overburden is underlain by the weathered and fractured Lockport Dolostone bedrock. Shallow groundwater levels fluctuate seasonally and allow groundwater to contact U contaminated soil, which promotes transport. This condition is exemplified through coincident increases in specific conductivity and groundwater levels, which flush soluble constituents in the fill/soil to groundwater during recharge events. In addition, water-level fluctuations affect reduction-oxidation (redox) conditions at the site. The U in soils is subject to wetting and drying cycles that promote oxidation more than stable redox conditions (e.g., dry soil or fully saturated conditions). This oxidizing mechanism increases uranium solubility and mobility. Site groundwater also receives uranium via leaching from near-surface contaminated fill. The strong correlation between nitrate and uranium in groundwater indicates that uranium is mobile where oxidizing conditions occur.
Analytical models of contaminant leaching determined that multiple pathways and transport mechanisms govern site risk. Uranium transport to groundwater involves three mechanisms: 1) direct ontact of contaminated soil with groundwater, 2) the oxidation-state or chemical valence of uranium, and 3) the leaching of near-surface contamination to groundwater. These mechanisms require an integrated remedial solution that is sustainable and cost effective.
This meeting is kindly being sponsored by SJB Service Inc.
