RISC Announcements
Table of Contents
RISC Updates
Changes affecting the RISC process occur from time to time. This page will provide updates on revisions or new procedures that affect site investigations, delineations, testing, and closure procedures.
Determining the Fraction of Organic Carbon in Soil – September 2007
IDEM announces that final Guidance has been issued on the appropriate method for determining the fraction of organic carbon (Foc) in soil samples. This parameter is very influential in calculating the amount of organic contaminants that can leach from the subsurface soil into the ground water and, therefore, in determining the migration to ground water closure level for those organic contaminants. Because the standard source for analytical methods for environmental media, EPA’s SW-846, does not contain a method for this parameter, there has been confusion about the appropriate method for determining the fraction of organic carbon in soil. With this Guidance, IDEM establishes the appropriate method for determining Foc in soils as well as the appropriate sampling procedure for collecting samples for analysis.
This new Guidance, Determining the Fraction of Organic Carbon RISC Nondefault Option, is also available on the Technical Information and Updates page.
RCRA Corrective Action Completion Determinations
Chapter 2 of the RISC User's Guide, "RCRA Closure and Corrective Action Program," has been updated to include a new section on how IDEM's Hazardous Waste Permit Section will process RCRA Subtitle C corrective action completion determinations. The chapter was also updated to be consistent with the changes from the Technical Guide updates. The new section 2.7.6, "Corrective Action Completion Determinations" will replace the existing sections 2.7.6 "No Further Action", 2.7.6.1 "Remediation to Background Concentrations" and 2.7.6.2 "Demonstration of Insignificant Threats to Human Health and the Environment." All of these topics are addressed in the new section which is modeled after U.S. EPA guidance. Also, a copy of the signed 2004 RCRA MOU with U. S. EPA is being added as Section 2.3 of Appendix 2 of the User's Guide.
IDEM Implements Method 5035A for Sampling VOCs
On March 2, 2007, IDEM announced the implementation of EPA SW-846 Method 5035A for volatile organic compounds (VOCs) sampling and issued supplemental guidance on the method. Please see the 5035A Announcement webpage for more information.
RISC Toolbox
The RISC website now includes several calculator tools to aid in default and nondefault site evaluations. Please see the RISC Toolbox webpage for more information and to download these tools.
Trichloroethylene (TCE) Closure Levels
This unique compound has been scrutinized since U.S. EPA released a Draft document with new toxicity information. In that guidance, U.S. EPA described a range of potency values that could be used to determine risk. Many U.S. EPA regions began to use the upper end of that range to calculate their screening levels. IDEM OLQ began actively researching this compound and released a paper, "A Regulatory Approach for Deriving Trichloroethylene Cancer Potency Estimates for use in the Development of Health Based Remediation Closure Levels," with new toxicity potency information for comment through the RISC listserv and RISC Web site on January 4, 2006. The TCE Response to Comments document was released on November 13, 2006. Please see the TCE Closure Levels Information webpage for these documents and other information about TCE closure levels.
If you have questions regarding RISC, please see the Contact about RISC webpage
- What should I do with my old computers and electronics?
- Where can I recycle?
- What are “Pay-as-You-Throw” programs?
- How can I get funding for recycling programs?
- What is “household hazardous waste”?
- Why is mercury dangerous?
- Where can I find information about available IDEM grants, loans, or funds?
- What are the benefits of recycling?
- What is composting and how do I do it?
- Where can I find information about flooding?
