Hazardous Waste Program

Missouri Risk-Based Corrective Action Process for Petroleum Storage Tanks

What's New

• June 3, 2011: The department issued an errata notice pertaining to the April 2005 version of Table 4-1, Soil Concentration Levels to Determine the Need for Groundwater Evaluation During Tank Closure, of the RBCA guidance. The notice concerns incorrect target levels in the table pertaining to TPH-GRO, TPH-DRO, C6-C8 Aliphatics, C8-C10 Aliphatics, C10-C12 Aliphatics and C12-C16 Aliphatics.

• Dec. 10, 2010: The department held a meeting/webinar to explain the tanks RBCA process and solicit participation for a stakeholder group that will help develop the tanks RBCA rules.

• Nov. 6, 2009: The department issued an errata notice pertaining to Appendix D of the January 2004 guidance. The notice concerns an incorrect conversion factor in the Appendix.

• Missouri Risk-Based Corrective Action, or MRBCA workshop – The Missouri Department of Natural Resources held an MRBCA workshop in Jefferson City on Oct. 9. The workshop covered the content and structure of the current Risk-Based Corrective Action rulemaking efforts and the revisions to the Tanks Risk-Based Corrective Action guidance document. The agenda, handouts, presentations, a Q-and-A document and a link to the draft rules are available on the workshop Web page. For more information, visit the departmental MRBCA Web page.

• The technical guidance currently in place and which will remain in place until the department's RBCA rules are effective is posted below.

Technical Guidance

• Soil Gas Sampling Protocol (04/05).
• Notice of Modifications to the Process and Interim Guidance Pertaining to Application of the New Soil Type Dependent Tier 1 Risk-Based Target Levels (03/05).
• Soil Type Determination Guidelines (03/05).
• Default Target Levels, Levels Triggering Groundwater Evaluation at Tank Closure and Tier 1 Soil Type Dependent Risk-Based Target Levels (06/11).

Note: These soil type dependent RBTLs replace those found in sections 3, 4 and 7 of the 2004 guidance found below.

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• Title Page, Acknowledgements, Foreword, Abbreviations (2004).
• Table of Contents, List of Tables (2004).
• Important Contact Information, Useful Internet Web Sites, DNR Regional and Satellite Offices (2004).
• Section 1 -- Introduction and Background (2004.)
• Section 2 -- Overview of MRBCA Process (2004).
• Section 3 -- Site Discovery and Initial Response (2004).
• Section 4 -- UST Closure Guidance (2004).
• Section 5 -- Site Characterization and Other Data Requirements for MRBCA Process (2004).
• Section 6 -- General Considerations for Risk Assessment (2004).
• Section 7 -- Tier 1 Risk Assessment (2004).
• Section 8 -- Tier 2 Risk Assessment (2004).
• Section 9 -- Tier 3 Risk Assessment (2004).
• Section 10 -- Risk Management Plan (2004).
• Section 11 -- Activity and Use Limitation Policy (2004).
• Section 12 -- Reporting (2004).
• Section 13 -- References (2004).
• Appendix A (2004).
• Appendix B -- Development of Risk Based Target Levels (2004).
• Appendix C -- Evaluation of Indoor Inhalation Pathway (2004).
• Appendix D -- A Method for Determining if a Water Bearing Unit Should be Considered an Aquifer (2009).
  • Nov. 6, 2009: The department is issuing an errata notice pertaining to Appendix D of the January 2004 guidance. The notice concerns an incorrect conversion factor in the Appendix.
• Appendix E -- Estimation of Representative Soil and Groundwater Concentrations (2004.)
• Appendix F -- Consideration of Total Petroleum Hydrocarbons within the MRBCA Process (2004).
• Appendix G -- MRBCA Report Forms (2004) -- For interactive Excel® versions of the MRBCA  forms, look under Reporting Forms header in  column to the right.

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Related Documents

• MRBCA Vapor Pathway Tech Memo Final (12/04).
• Comparison of Soil Type Dependent Tier 1 Risk-Based Target Levels For Benzene and TPH-GRO (12/04).
• Log of Tier 1 - Tier 2 Form changes (0804).
• Letter to Underground Storage Tank owners (03/04).
• Beneficial Use of Petroleum Contaminated Soil.
• City of St. Louis Groundwater Ordinance and Memorandum of Understanding with the department.
  • St Louis Groundwater MOU.

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Fact Sheets: MRBCA for Petroleum Storage Tank Sites

• Preservation of Samples Analyzed for Volatile Organic Compounds Fact Sheet-- PUB2159 (04/05).
• Sampling for Polynuclear Aromatic Hydrocarbons, Fact Sheet-- PUB2160 (04/05) .
• Analysis of Petroleum Hydrocarbon Fractions, Fact Sheet-- PUB2161 (04/05).
• Applicability of Vapor Pathway to Soil, Fact Sheet-- PUB2162 (04/05) .

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Reporting Forms

• Tier 1 - Tier 2 Assessment Forms Zip XLS (11/04).

Note: When opening the Tier 1 - 2 Excel files, a series of dialogues will be presented.
Click OK if "missing file" warnings appear, there are no missing files
Click Enable Macros when given the option. Several functions of the forms use macros.
Click No when asked to update links, there are no external links to update.

Note: The risk-based target levels that appear on forms Tier 1-12(1) through Tier 1-12(10) are not current and, therefore, the forms should not be used as part of a risk assessment report. Alternatively, forms Tier 2-2(1) through Tier 2-2(10) or a table or spreadsheet of your own construction may be used for Tier 1 reporting. To use the Tier 2-2 forms at Tier 1, enter both a representative concentration and a current, soil type dependent risk-based target level on the forms. Cross through the form number in the upper right corner and write in the corresponding Tier 1 form number (e.g., Tier 1-12(1)).