Demonstration of the use of test results from the Leaching Environmental Assessment Framework (LEAF) to develop screening-level leaching assessments

• Published in: Waste management (Elmsford) Vol. 121; pp. 226 - 236
• Main Authors: Garrabrants, Andrew C., Kosson, David S., Brown, Kevin G., Fagnant, Daniel P., Helms, Gregory, Thorneloe, Susan A.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 15.02.2021
• Subjects: Chromium; Construction Materials; Environmental Pollution; Leaching assessment; LEAF; S/S soil; Screening; Smelter soil; Soil; Soil Pollutants - analysis; Screening; S/S soil; LEAF; Leaching assessment; Smelter soil
• ISSN: 0956-053X; 1879-2456
• DOI: 10.1016/j.wasman.2020.12.016

[Display omitted] •Tiered methodology for screening-level assessment using LEAF test results.•Leaching assessment of copper/lead smelter soil before and after treatment.•Assessment ratios based on estimated leaching and threshold concentrations.•Assessment ratios less than one indicate that leaching may not be a concern.•Illustrated approach for reducing set of constituents of potential concern. Environmental management often benefits from leaching assessment as a predictive tool for estimating constituent leaching from solid and waste materials. The Leaching Environmental Assessment Framework (LEAF) provides both validated tests methods for characterizing materials and a methodology for developing screening assessments based on material characterization results. The use of LEAF data in a screening-level environmental assessment approach is demonstrated through a hypothetical case study of copper/lead smelter soil remediation. The LEAF test methods characterize leaching behavior from a wide range of materials as either constituent liquid-solid partitioning as functions of pH and liquid-to-solid ratio (L/S) or as a rate of constituent mass transport. In this study, leaching characteristics of a contaminated smelter soil and the same soil treated by solidification/stabilization with Portland cement were compared to hypothetical environmental thresholds. Screening assessments were developed for total content, available content, and maximum concentrations over relevant pH domains and L/S ranges. Assessment ratios for barium, beryllium, and fluoride indicated that estimated leaching would be less than thresholds in both materials and these constituents were removed from further analysis. Similarly, chromium (in soil) and zinc (in solidified material) were screened from further analysis. For the remaining constituents, scenario-based assessment could refine estimated leaching concentrations by considering anticipated conditions of leaching scenario.