The Indiana Department of Environmental Management (IDEM) is proposing changes to the use of the Risk-Integrated System of Closure (RISC), which will affect all of its remedial programs, including leaking underground storage tanks, state cleanup, voluntary remediation, hazardous waste closures, RCRA corrective action and brownfields.

On June 11, 2008, IDEM published a First Notice of Comment Period regarding the development of new RISC rules. Comments are due Friday, July 11, 2008. Under IDEM's current proposal, the framework of its RISC-based environmental assessments would be based on rules rather than guidance documents as is currently the case.

The new proposed RISC rules would provide a regulatory framework to establish, among other things:

  • Criteria for demonstration of impracticability to clean up contamination to applicable closure levels and selection of remedial alternatives, including practicability, long-term reliability, effectiveness and implementation risk.
  • Criteria for IDEM to apply in approving or denying proposed remediation plans, including a hierarchy, or order of preference, for closure that prefers treatment or removal of contaminants to the extent practicable to achieve a permanent remedy before administrative or engineering exposure prevention options may be used to address remaining contaminants.
  • Standards for the IDEM to apply in approving or denying requests for closure and the various related mechanisms for documenting closure and imposing any conditions of closure such as land use restrictions or engineering controls to prevent human exposure to contaminants.
  • Requirements for post-closure reporting, monitoring, inspection, certification, maintenance and financial assurance to prevent human exposure to contaminants for sites that have closed with an environmental restrictive covenant (ERC) or other controls.

IDEM is also in the process of rewriting its 2001 RISC Technical Guide, a non-rule policy document, which provides both default and non-default approaches to site closure. Some of the possible changes to the RISC guidance documents are the addition of: (1) a technical impracticability chapter which may allow IDEM to require cleanup of contamination to the extent practicable unless it is "technically impracticable"; (2) a land use controls appendix which will address IDEM's approach to the use of institutional controls; (3) a vapor intrusion appendix; (4) a plume stability appendix; (5) appendix containing tables with new default closure levels; and (6) considerations for "green remediation."