BEFORE THE DEPARTMENT OF ENVIRONMENTAL QUALITY

OF THE STATE OF MONTANA

 

In the matter of the amendment of ARM 17.50.1612, 17.50.1617, 17.50.1618, 17.55.109, 17.56.507, and 17.56.608 pertaining to incorporation by reference

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NOTICE OF PROPOSED AMENDMENT   (STATE SUPERFUND, PETROLEUM TANK CLEANUP, AND SOLID WASTE)   NO PUBLIC HEARING CONTEMPLATED

 

TO: All Concerned Persons

 

1. On May 20, 2024, the Department of Environmental Quality proposes to amend the above-stated rules.

 

2. The Department of Environmental Quality will make reasonable accommodations for persons with disabilities who wish to participate in this rulemaking process or need an alternative accessible format of this notice. If you require an accommodation, contact the Department of Environmental Quality no later than 5:00 p.m. on February 1, 2024, to advise us of the nature of the accommodation that you need. Please contact the Department of Environmental Quality at P.O. Box 200901, Helena, Montana 59620-0901; phone (406) 444-1388; fax (406) 444-4386; or e-mail DEQMAR17-438rule@mt.gov.

 

            3. General Reason Statement:  Through this rulemaking, the department is proposing to adopt and incorporate by reference the most recent edition of the federal Drinking Water Maximum Contaminant Levels (MCLs), the U.S. Environmental Protection Agency Regional Screening Levels (RSLs), the Reportable Quantities for Hazardous Substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), and the Montana Risk-Based Corrective Action Guidance for Petroleum Releases.  The department conducts periodic reviews of the Montana Risk-Based Corrective Action Guidance for Petroleum Releases to determine if changes to methods and toxicity information warrant updating the guidance.  In addition to minor editorial changes, the following substantive updates were made in the December 2023 edition:

 

Readability and Usability of the Document: New tables were added to the document to walk the user through the Tier 2 risk-based screening level (RBSL) adjustment, and instructions were added to help the user determine the appropriate Tier 2 RBSL for each release.

A new Appendix D was added to provide an expanded discussion on the derivation of groundwater RBLSs and a discussion on actions needed based on exceedances of water quality standards or screening levels.

The order of compounds in the screening tables was rearranged to be consistent with the most common laboratory reports.

 

Revisions for Montana-specific Conditions: Residential and commercial worker RBSLs were recalculated to incorporate the Montana State Exposure Frequencies.  These include factors specific to Montana's weather patterns, specifically frozen ground during the winter.

 

Increased Protection for Construction Workers and Other Users: Several construction worker RBSLs were recalculated using sub-chronic toxicity values rather than chronic toxicity values.

Clarification was added for evaluating construction worker exposure using soil sample data collected throughout the entire 0 - 10 foot interval.

All direct contact non-carcinogenic RBSLs were recalculated to incorporate a hazard quotient of 0.1 (instead of 0.125) to ensure protectiveness in the initial screening phase. This will allow up to 10 (instead of 8) non-carcinogenic compounds present in the initial screening.

 

Toxicity and Data Reference Updates: Comprehensive review was completed of all equation inputs for both direct contact (soil) and water RBSLs. Updates were made where needed based on updates to chemical specific toxicity values or data reference updates. Final RBSLs either increased or decreased based on the chemical and receptor.

 

A copy of the Montana Risk-Based Corrective Action Guidance for Petroleum Releases (December 2023) may be obtained by contacting Terri Mavencamp at (406) 444-5595.  In addition, a copy of the document has been posted to the department's website at https://deq.mt.gov/public/publiccomment. 

 

Reasons for the remainder of the proposed incorporation by references updates are discussed below.

 

4. The rules as proposed to be amended provide as follows, new matter underlined, deleted matter interlined:

 

(2) and (3) remain the same.

 

AUTH: 75-11-319, 75-11-505, MCA

IMP: 75-11-309, 75-11-505, MCA

 

REASON: In (1)(c), the department is proposing to adopt and incorporate by reference the most recent edition of the Tables set forth in the U.S. Environmental Protection Agency, Regional Screening Levels (RSL) for Chemical Contaminants at Federal Superfund Sites (November 2023) to provide the most current screening levels to protect human health and the environment.  RSLs provide a screening level calculation tool to assist risk assessors, remedial project managers, and others involved with risk assessment and decision-making at sites in developing or refining screening levels. In (1)(d) the department is proposing to adopt and incorporate by reference the most recent Reportable Quantities for Hazardous Substances under section 102(a) of the Comprehensive Environmental Response, Compensation and Liability Act published at 40 CFR Part 302. Spills or overfills of a hazardous substance over its reportable quantity under 40 CFR Part 302 result in a release to the environment.

            A copy of the U.S. Environmental Protection Agency, Regional Screening Level Tables (November 2023) may be obtained by contacting Terri Mavencamp at (406) 444-5595.  In addition, a copy of the document is available at https://www.epa.gov/risk/regional-screening-levels-rsls-generic-tables.

 

 

5. Concerned persons may submit their data, views, or arguments concerning the proposed action in writing to the Department of Environmental Quality, P.O. Box 200901, Helena, Montana, 59620; telephone (406) 444-1388; fax (406) 444-4386; or e-mail DEQMAR17-438rule@mt.gov, and must be received no later than 5:00 p.m., February 9, 2024.

 

6. If persons who are directly affected by the proposed actions wish to express their data, views, or arguments orally or in writing at a public hearing, they must make written request for a hearing and submit this request along with any written comments to the department at the above address no later than 5:00 p.m., February 9, 2024.

 

7. If the agency receives requests for a public hearing on the proposed action from either 10 percent or 25, whichever is less, of the persons directly affected by the proposed action; from the appropriate administrative rule review committee of the Legislature; from a governmental subdivision or agency; or from an association having not less than 25 members who will be directly affected, a hearing will be held at a later date. Notice of the hearing will be published in the Montana Administrative Register. Ten percent of those directly affected has been determined to be 227 persons based on the combination of:  the number of regulated petroleum facilities in Montana (1,199), the number of petroleum release sites currently undergoing remediation (896), the number of state superfund facilities (175), and the number of permitted landfarms (3) where one or more of the updated references would be applicable. It is possible other entities may be directly affected by the proposed action (e.g., sites with contamination not yet identified, etc.), but it would be difficult to definitively identify them so the department has conservatively used its lists of identified/regulated sites where these screening levels are applicable.

 

8. The department maintains a list of interested persons who wish to receive notices of rulemaking actions proposed by this agency. Persons who wish to have their name added to the list shall make a written request that includes the name, e-mail, and mailing address of the person to receive notices and specifies for which program the person wishes to receive notices. Notices will be sent by e-mail unless a mailing preference is noted in the request. Such written request may be mailed or delivered to the contact person in paragraph 5 or may be made by completing a request form at any rules hearing held by the department.

 

9. An electronic copy of this proposal notice is available through the Secretary of State's web site at http://sosmt.gov/ARM/Register. 

 

10. With regard to the requirements of 2-4-111, MCA, the department has determined that the amendment of the above-referenced rules will not significantly and directly impact small businesses.

 

 

/s/ Nicholas Whitaker                                   /s/ Christopher Dorrington            

NICHOLAS WHITAKER                              CHRISTOPHER DORRINGTON

Rule Reviewer                                             Director

                                                                     Department of Environmental Quality

           

Certified to the Secretary of State January 2, 2024.