When transportation agencies become involved in the remediation of hazardous waste on their sites, the common practice is to hire consultants and contractors for the clean up process. Because the field of hazardous waste site remediation is changing so rapidly, agency personnel evaluate the consultant's recommendations need to have access to the most recent regulatory and remediation information. Early stages of the remediation process typically involve site assessment, and the identification of feasible technologies for treatment. A user-friendly computerized methodology was developed for screening out the most inappropriate treatment technologies for a specific waste at a specific site. The STEP model was developed for this purpose using knowledge-base expert system techniques.