RISC Technical Guidance Revision Project Information
Project Overview
The current edition of the Risk Integrated System of Closure (RISC) Technical Resource Guidance Document (Technical Guide) was approved in 2001. Since that time risk assessment science and methodology have advanced and some laws affecting cleanups have changed. The Office of Land Quality is updating and revising the Technical Guide with the following project objectives in mind:
- Bring risk assessment methodology up to date.
- Incorporate guidance for evaluating vapor intrusion and recreational exposure scenarios.
- Implement House Enrolled Act 1162 (now referenced as Public Law 78-2009) amendments enacted during the 2009 legislative session – including new guidance on remedies which manage risks and control completed or potential exposure pathways.
- Streamline the text to improve overall clarity and consistency of application.
- Incorporate a “weight of evidence” approach for site-specific risk assessments.
- Partner with stakeholders throughout the project.
Project status updates will be posted under the Project Status banner below. Draft documents, presentations and other information will be posted under the Project Information banner below.
Project Status
IDEM plans to begin the nonrule policy document approval process with the release of a draft for public comment by the end of the year 2010. Currently work groups comprised of IDEM scientists and managers, and external stakeholders - including environmental consultants, local government officials, water utilities and industry - are discussing a number of topics with the goal of providing technical input to support the policy development process.
IDEM is working with the Midwestern States Environmental Consultant’s Association on the following topics:
- Background & Offsite Sources: This work group is developing procedures for determining concentrations of contaminants unrelated to site activities including naturally occurring background, anthropogenic background and off-site sources.
- Closure Tables: This work group is updating the risk assessment methodology used in calculating the RISC Default Closure Levels.
- Plume Stability: This work group is developing procedures for evaluating the stability of ground water contaminant plumes.
- Site Characterization: This work group is developing recommendations for site investigation procedures including the use of a conceptual site model to facilitate site characterization and risk assessment.
- Total Petroleum Hydrocarbons: This work group is working on a number of technical issues related to TPH with the goal of updating the current TPH content of the RISC Technical Guide.
- Vapor Intrusion: This work group is working to update and revise the 2006 Draft Vapor Intrusion Pilot Program Guidance with the goal of incorporating vapor intrusion guidance into the RISC Technical Guide.
IDEM is working with other stakeholders on the following topics:
- Wellhead Protection Areas: IDEM is working with local government officials, water utilities and other ground water resource stakeholders on a number of topics related to remediation projects in wellhead protection areas.
- Manufactured Gas Plant Sites: IDEM is working with representatives of Citizens Energy, Duke Energy, NiSource and Vectren on the unique environmental investigation and cleanup issues related to former manufactured gas plant (MGP) sites.
Project Information
- HEA 1162 information for local units of government and water utilities - February 18, 2010 [PDF]
- HEA 1162 Interim Implementation Document Consultant’s Day Presentation - December 9, 2009 [PDF]
- House Enrolled Act 1162 Interim Implementation Document - December 7, 2009 [PDF]
For More Information
If you have questions regarding this project, please contact the RISC section staff.
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