The Indiana Department of Environmental Management has issued their draft of the Remediation Closure Guide (available here http://www.in.gov/idem/6683.htm). This guide is intended as a replacement of the RISC Technical Guide, and to serve as the de facto guidance document for all environmental investigations to be performed under IDEM's regulatory programs.
Of note, the guidance document explicitly requires the development of a Conceptual Site Model of its investigated sites. The CSM is to integrate hydrogeologic settings, land use, identification of contaminants and their phases, plume characterization, and possible off-site and natural sources. We applaud this approach and believe that its implementation will result in more thoughtful and efficient investigations that will be a benefit to the citizens of Indiana.