Hazardous Waste Program
Missouri Risk-Based Corrective Action, or MRBCA
Departmental Technical Guidance
The Risk-Based Corrective Action Technical Guidance is published by the Missouri Department of Natural Resources' Hazardous Waste Program.
The Hazardous Waste Program administers two risk-based corrective action processes:
- The Risk-Based Corrective Action Process for Petroleum Storage Tanks is applicable to releases from petroleum storage tanks.
- The Missouri Risk-Based Corrective Action process, generally referred to as the Departmental MRBCA, applies to releases from sources other than petroleum storage tanks and is available below. Sites participating in the department’s Brownfields/Voluntary Cleanup Program are evaluated under the Departmental MRBCA guidance and rule 10 CSR 25-18.010, Risk-Based Corrective Action Process, also available below.
The MRBCA process detailed in the guidance below provides a policy for remediation decisions at contaminated sites. The process is used to determine site-specific cleanup standards that are protective of human health and the environment under current and future site use and in consideration of other site-specific characteristics.
The final guidance is posted below. Updates made to the guidance since the initial version was released in April 2006 have been incorporated into this version of the guidance. Information regarding each specific update can be accessed on the MRBCA Updates Web page. Information will be posted to this and the updates page regarding any future changes, and the guidance below will be amended accordingly.
Departmental Missouri Risk-Based Corrective Action (MRBCA) Technical Guidance
(Section 1-13) (April 2006, including all subsequent updates)
Departmental Missouri Risk-Based Corrective Action (MRBCA) Technical Guidance (Appendices) (April 2006, including all subsequent updates)
Missouri Risk-Based Corrective Action Process Rule
The Risk-Based Corrective Action Process rule, 10 CSR 25-18.018, became effective on October 30, 2009. The full text of the rule is available in the online edition of the Code of State Regulations.
Fact Sheet Replaces Oct. 20, 2006 - MRBCA Policy about Off-site Groundwater Contamination (06/10)
The October 20, 2006, “Policy Statement to Be Incorporated in the MRBCA Guidance" has been replaced with a new fact sheet, Closure of Sites with Contamination off the Source Property. The new fact sheet supersedes the October 20, 2006 policy. For more information about the technical bulletin, contact the Brownfield Voluntary Cleanup Program at 573-526-8913.
New Fact Sheet Regarding Management of Contamination Originating off the Property (06/10)
The department has developed a new fact sheet titled Management of Contamination Originating off the Property. The fact sheet addresses situations where contamination has migrated onto a Brownfields/Voluntary Cleanup Program site. For more information regarding the fact sheet, contact the Brownfields/Voluntary Cleanup Program at 573-526-8913.
Additional technical bulletins and fact sheets pertaining to MRBCA, the Brownfields/Voluntary Cleanup Program and other hazardous waste-related issues, are available on the department's publications Web page.
Technical Guidance Sections listed individually:
(Same as above; April 2006, plus all subsequent updates published in June 2006 and June 2008)
Note: All the files listed below are available in Adobe® Acrobat® format.
- Acknowledgements, List of Abbreviations, Table of Contents, List of Tables, List of Figures (April 2006)
- Section 1 -- Background and Objective (April 2006)
- Section 2 -- Overview of MRBCA Process (April 2006)
- Section 3 -- Remediation Authorities in Missouri (April 2006)
- Section 4 -- Management of Imminent Threat(s) (April 2006)
- Section 5 -- Initial Site Characterization and Comparison with Default Target Levels and Water Quality Criteria (April 2006)
- Section 6 -- Development and Validation of Conceptual Site Model (April 2006)
- Section 7 -- Selection of Chemicals of Concern (COCs) for MRBCA Evaluation (April 2006)
- Section 8 -- Tier 1 Risk Assessment (April 2006)
- Section 9 -- Tier 2 Risk Assessment (April 2006)
- Section 10 -- Tier 3 Risk Assessment (April 2006)
- Section 11 -- Long-Term Stewardship for Risk-Based Corrective Action Sites (June 2008)
- Section 12 -- Risk Management Plan (April 2006)
- Section 13 -- References (April 2006)
Technical Guidance Appendices listed individually: (Same as above; April 2006, plus all subsequent updates published in June 2006 and June 2008)
- Appendix A -- Updates and Revisions to the MRBCA Technical Guidance (April 2006)
- Appendix B -- Default Target Levels and Tier 1 Risk-Based Target Levels (June 2006)
- Appendix C -- Estimation of Representative Soil and Groundwater Concentrations (April 2006)
- Appendix D -- Procedure for Review of the Risk-Based Corrective Action (RBCA) Decisions (April 2006)
- Appendix E -- Development of Risk-Based Target Levels (April 2006)
- Appendix F -- Ecological Risk Assessment Checklists (April 2006)
- Appendix G -- A Method for Determining if a Water Bearing Unit Should Be Considered an Aquifer (December 2006)
- Appendix H -- Measurement of Soil Vapor Levels (April 2006)
- Appendix I -- Flexibility in Calculation of Tier 2 and Tier 3 Site-Specific Target Levels (April 2006)
- Appendix J -- Appendix to Section 11 Long-Term Stewardship for Risk-Based Remediation Sites (June 2008)
- Appendix K -- Data Quality Management Plan (April 2006)
- Appendix L -- Definitions (April 2006)
- Appendix M -- Site-Specific Background Concentrations (April 2006)
- Appendix N -- Cleanup Levels for Surfaces and Building Interiors (April 2006)
- Appendix O -- Soil Type Determination Guidelines (April 2006)
- The Missouri Environmental Covenants Act, Fact Sheet -- PUB2414
- City of St. Louis Groundwater Ordinance and Memorandum of Understanding with the department