This issue highlights the use of compound specific isotope analysis (CSIA), an environmental forensics technique used to characterize contaminated sites and the progress of bioremediation and natural attenuation. CSIA measures and compares the ratios of stable isotopes found in compounds of suspected contaminant sources or plumes as well as the feedstock or manufacturing process of materials historically used in a site's vicinity. Isotopic analysis can help discern the potential for multiple spills of the same compound based on their different isotopic "signatures." An isotopic signature can be used to associate a contaminant plume with a particular spill or potentially responsible party. It also can be used to evaluate the extent of contaminant degradation caused by microbes during natural attenuation (February 2010, 6 pages).

Solidification/Stabilization (S/S) is a widely used treatment technology to prevent migration and exposure of contaminants from a contaminated media (i.e. soil, sludge and sediment). Solidification refers to a process that binds a contaminated media with a reagent changing its physical properties. Stabilization refers to the process that involves a chemical reaction that reduces the leachability of a waste. S/S treatment and application is primarily used at hazardous waste sites. This Technology Performance Review (TPR) includes a discussion on several sites, and addresses important factors to consider in the selection of S/S treatment. Each S/S case study has a brief project description, regulatory status, S/S treatment process that includes binder materials used, and a summary of the performance data. Estimated treatment costs and maintenance activities are also included when available. Estimated costs must be adjusted for inflation and current material price increases (November 2009, 28 pages).