Information on classes and concentrations of chemical contaminants, how they are distributed through out the site, and in what media they appear is essential to begin the preselection of treatment technologies. In this document, contaminants have been separated into eight contaminant groups as follows:

• Nonhalogenated volatile organic compounds (VOCs).
• Halogenated volatile organic compounds.
• Nonhalogenated semivolatile organic compounds (SVOCs).
• Halogenated semivolatile organic compounds
• Fuels.
• Inorganics.
• Radionuclides.
• Explosives.

This section presents a discussion of the properties and behaviors of the contaminant groups, followed by a discussion of the most commonly used treatment technologies available for that contaminant group. (Less commonly used treatment technologies are identified in the treatment technology screening matrix and may be found in Section 4.) Each discussion of the contaminant groups is divided into two media classifications: (1) soil, sediment, and sludge and (2) ground water, surface water, and leachate. (The nonhalogenated and halogenated VOC contamination sections additionally address air emissions and off-gases.)

A matrix summarizing treatment technology information is presented for each contaminant group. It should be noted that these technologies are not necessarily effective at treating all contaminants in the contaminant group. Information summarized includes the development status (full-scale or pilot-testing), the use rating (widely/commonly used or limited use), the applicability rating (better, average, or below average), the system reliability (better, average, or below average), the cleanup time (long, average, or short) and the treatment function (destruction, extraction, or immobilization). The "use" rating was determined from information presented in the Treatment Technologies Applications Matrix for Base Closure Activities (California Base Closure Environmental Committee, 1994). The applicability rating was determined from information presented in the second edition of this document (FRTR, 1994). These rating codes were reviewed in 1997. Please note, a treatment technology may be applicable to treat a specific contaminant group, but may not be widely used because of factors such as cost, public acceptance, or implementability. All information presented in these matrices has been subjected to rigorous FRTR member review and amended where appropriate for the purposes of this document.

Subsection 2.1 presents a discussion of the presumptive remedy process. Subsection 2.2, Data Requirements, addresses the specific data elements required to characterize each medium and the impact on technology selection. Discussion of each of the eight contaminant groups appears in Subsections 2.3 to 2.10.

Pilot scale describes all techniques not yet developed to full-scale, including those still in the bench-scale phase of development.