This second edition of EPA's bestselling book, Description and Sampling of Contaminated Soils: A Field Guide, Second Edition, has been revised and significantly expanded over the original edition. An ideal reference for anyone involved in site investigations, this guide describes how to determine the amount and extent of soil contamination and potential for movement of contaminants in the soil and groundwater. It contains checklists, tables, and step-by-step descriptions of methods and procedures for: Cost-effective, detailed site investigations for evaluating the potential for contaminant transport Field collection of information on soil engineering properties required for remediation selection and design This guide also features an adaptation of soil description procedures used by the U.S. Soil Conservation Service (SCS) for investigating contaminated sites. The SCS soil description and classification procedures, when used in combination with the Unified Soil Classification System currently used by geologists and engineers, greatly improves contaminated site assessments.

Bioavailability refers to the extent to which humans and ecological receptors are exposed to contaminants in soil or sediment. The concept of bioavailability has recently piqued the interest of the hazardous waste industry as an important consideration in deciding how much waste to clean up. The rationale is that if contaminants in soil and sediment are not bioavailable, then more contaminant mass can be left in place without creating additional risk. A new NRC report notes that the potential for the consideration of bioavailability to influence decision-making is greatest where certain chemical, environmental, and regulatory factors align. The current use of bioavailability in risk assessment and hazardous waste cleanup regulations is demystified, and acceptable tools and models for bioavailability assessment are discussed and ranked according to seven criteria. Finally, the intimate link between bioavailability and bioremediation is explored. The report concludes with suggestions for moving bioavailability forward in the regulatory arena for both soil and sediment cleanup.

The U.S. Environmental Protection Agency is developing Ecological Soil Screening Level (Eco-SSL) benchmarks for ecological risk assessment of contaminants at Superfund sites. Benchmarks for invertebrates Were developed from existing literature. Insufficient information for Ba, Be, Mn, and Sb to generate Eco-SSLs necessitated standardized toxicity testing to fill the data gaps. We used the Enchytraeid Reproduction Test (ERT) with Enchytraeus crypticus in this study. This test was selected on the bases of its ability to measure chemical toxicity to ecologically relevant test species during chronic assay, and its inclusion of at least one reproductive component among the measurement endpoints. Tests were conducted in Sassafras sandy loam soil, which supports relatively high bioavailability of metals. Aging/weathering procedures for amended treatment soil were incorporated into the study to better reflect the "real world" exposure conditions. The toxicity order based on juvenile production was Be> Mn> Sb> Ba with EC20 values of 45, 116, 194, and 585 mg kg-1, respectively. These results show that ERT is a robust and sensitive assay for toxicity assessments and is appropriate for the Eco-SSL development.