Laws and Regulations

Administrative Rules of Montana

DEQ is responsible for administering and enforcing several chapters of rules within Title 17 of the Administrative Rules of Montana (ARM). The links below to the specific chapters on the Montana Secretary of State website are provided as a convenience for interested parties. Administrative rules are periodically reviewed and revised by DEQ and some lapse in time may occur between adoption and the electronic posting of new or revised rules. Electronic rules on the Secretary of State website are updated quarterly and may not reflect the most current version adopted. For an official version of the Administrative Rules of Montana, please contact the Secretary of State at (406) 444-2055.

Table of Contents (Title 17)

Chapter 1 - Organization of Department
Chapter 4 - Procedural Rules
Chapter 8 - Air Quality
Chapter 20 - Major Facility Siting
Chapter 24 - Reclamation
- Hard Rock Mining - Subchapter 1
- Opencut Mining - Subchapter 2
- Coal Mining - Subchapters 3-18
Chapter 30 - Water Quality
Chapter 35 - Vessel Pumpout Facilities
Chapter 36 - Subdivisions/On-Site Subsurface Waste Water Treatment
Chapter 38 - Public Water and Sewage System Requirements
Chapter 40 - Water Treatment Plants and Operators
Chapter 50 - Solid Waste Management
Chapter 53 - Hazardous Waste
Chapter 54 - Hazardous Waste Management (repealed)
Chapter 55 - CECRA Remediation
Chapter 56 - Underground Storage Tanks / Petroleum & Chemical Substances
Chapter 57 - Aboveground Storage Tanks
Chapter 58 - Montana Petroleum Tank Release Compensation Board
Chapter 74 - Occupational Health (Asbestos)
Chapter 80 - Tax Certification - Pollution Control Equipment and Energy Facilities
Chapter 84 - Renewable Energy Credit and Loan Program
Chapter 85 - Alternative Energy Revolving Loan Program
Chapter 86 - Wind Generation Facility Decommissioning and Bonding
MCA-ARM - MCA to ARM Cross Reference

Montana Code Annotated

The laws in the Montana Code Annotated are passed by the Montana State Legislature, which consists of the Montana House of Representatives and the Montana Senate. DEQ is charged with protecting a clean and healthy environment as guaranteed to our citizens by our State Constitution in Titles 75, 76, and 82, Montana Code Annotated.

Statutes

Final Rule Adoption and Amendment Notices

In the table below you will find information on DEQ rulemaking for the past two years. Each archived rule notice includes a link to official public notices on the Montana Secretary of State's website. If you are looking for older information, please contact Loryn Johnson 406-444-1388.

Latest DEQ adopted ARMS

Effective Date	Purpose & Link to Online Rule Notices
March 28, 2025	MAR 17-451 - Notice of Adoption (ARM 17.8.101, 17.8.308, 17.8.743, 17.8.1601, 17.8.1701, 17.24.101, 17.24.206, 17.24.212, 17.24.218, 17.24.219, 17.24.221, 17.24.222, 17.24.225, 17.24.313, 17.24.321, 17.24.324, 17.24.639, 17.24.815, and 17.24.1303) Issue 6 of the 2025 MAR.
January 11, 2025	MAR 17-449 - Notice of Amendment and Repeal (ARM 17.4.101 and 17.4.202) Issue 1 of the 2025 MAR.
January 11, 2025	MAR 17-448 - Notice of Amendment (ARM 17.50.411, 17.50.540, 17.50.801, 17.50.806, and 17.50.810) Issue 1 of the 2025 MAR.
September 21, 2024	MAR 17-446 - Notice of Amendment and Repeal (Underground Storage Tanks - amendment of ARM 17.56.101, 17.56.306, 17.56.1303, 17.56.1304, 17.56.1402, 17.56.1403, 17.56.1404, 17.56.1406, and 17.56.1407 and the repeal of ARM 17.56.1308, 17.56.1309, and 17.56.1409). Issue 18 at page 2201 of the 2024 MAR.
September 21, 2024	MAR 17-444 - Notice of Amendment (Subdivision - amendment of ARM 17.36.126 adoption of a new version of Department Circular DEQ-8). Issue 18 at page 2191 of the 2024 MAR.
September 7, 2024	MAR 17-442 - Notice of Adoption and Amendment (Public Water Supply - adoption of NEW RULE I and the amendment of ARM 17.36.126, 17.38.101, 17.38.234 and the amendment to Circular DEQ-1). Issue 17 at page 2144 of the 2024 MAR.
August 24, 2024	MAR 17-447 - Notice of Amendment (Water Quality - amendment of ARM 17.36.103). Issue 14 at page 2057 of the 2024 MAR.
August 24, 2024	MAR 17-445 - Notice of Amendment (Air Quality - amendment of ARM 17.8.102, 17.8.103, 17.8.202, 17.8.301, 17.8.302, 17.8.342, 17.8.604, 17.8 740, 17.8.744, 17.8.802, 17.8.902, 17.8.1002, 17.8.1107, 17.8.1202, 17.8.1313, 17.8.1402, and 17.8.1815). Issue 16 at page 2056 of the 2024 MAR.
July 27, 2024	MAR 17-443 - Notice of Amendment and Repeal (Major Facility Siting Act - amendment 17.20.1304, 17.20.1505, 17.20.1604, 17.20.1606, 17.20.1607, and the repeal of 17.20.818, 17.20.907, 17.20.920, 17.20.921, 17.20.922, 17.20.923, 17.20.924, 17.20.928, and 17.20.929). Issue 14 at page 1879 of the 2024 MAR.
July 27, 2024	MAR 17-441 - Notice of Amendment (Motor Vehicle Recycling and Disposal - amendment of ARM 17.50.213) Issue 14 at page 1878 of the 2024 MAR.
June 6, 2024	MAR 17-439 - Notice of Amendment (Water Quality amendment of ARM 17.30.508, 17.30.517, 17.30.702, 17.30.715, 17.30.716, and 17.30.718). Issue 13 at page 1581 of the 2024 MAR.
May 11, 2024	MAR 17-438 - Notice of Amendment (State Superfund, Petroleum Tank Cleanup and Solid Waste - amendment of ARM 17.50.1612, 17.50.1617, 17.50.1618, 17.55.109, 17.56.507, and 17.56.608). Issue 9 at page 1062 of the 2024 MAR.
May 11, 2024	MAR 17-437 - Notice of Adoption, Amendment, and Repeal (Mining Bureau - NEW RULE I, the amendment of ARM 17.24.102, 17.24.107, 17.24.116, 17.24.118, 17.24.128, 17.24.132, 17.24.141, 17.24.144, 17.24.145, 17.24.146, 17.24.150, 17.24.159, 17.24.166, and 17.24.171, and the repeal of ARM 17.24.165 and 17.24.170). Issue 9 at page 1060 of the 2024 MAR.
April 13, 2024	MAR 17-436 - Notice of Amendment and Repeal (Asbestos - amendment to ARM 17.74.350, 17.74.351, 17.74.352, 17.74.353, 17.74.354, 17.74.355, 17.74.356, 17.74.357, 17.74.358, 17.74.359, 17.74.360, 17.74.362, 17.74.363, 17.74.364, 17.74.365, 17.74.366, 17.74.367, 17.74.368, 17.74.369, and 17.74.409, and repeal of ARM 17.74.343, 17.74.370, 17.74.371, and 17.74.372). Issue 7 at page 723 of the 2024 MAR.
March 9, 2024	MAR 17-435 - Notice of Repeal (State Superfund - ARM 17.55.110). Issue 5 at page 471 of the 2024 MAR.
February 24, 2024	MAR 17-440 - Notice of Amendment and Repeal (Petroleum Tank Release Compensation Board - ARM 17.58.336 and 17.58.344 and the repeal of ARM 17.57.101, 17.57.102, 17.57.103, 17.57.104, 17.57.105, 17.57.106, and 17.57.107). Issue 4 at page 329 of the 2024 MAR. Petro Board
February 10, 2024	MAR 17-433 - Notice of Adoption and Amendment (Water Protection - NEW RULE I and NEW RULE II and the amendment of ARM 17.30.1001, 17.30.1005, 17.30.1010, 17.30.1022, 17.30.1023, 17.30.1024, 17.30.1033, 17.30.1040, and 17.30.1041). Issue 3 at page 262 of the 2024 MAR.
February 10, 2024	MAR 17-432 - Notice of Amendment and Repeal (MAR 17-432A, MAR 17-432B, MAR 17-432C, MAR 17-432D, and MAR 17-432E) Issue 3 at pages 253 through 261 of the 2024 MAR.MAR 17-432C hearing transcript
December 23, 2023	MAR 17-431 - Notice of Amendment (Air Quality - ARM 17.8.202). Issue 24 at page 1863 of the 2023 MAR.
December 23, 2023	MAR 17-430 - Notice of Adoption and Amendment (Subdivision - NEW RULE I and NEW RULE II and the amendment of ARM 17.36.101, 17.36.112, 17.36.123, 17.36.310, 17.36.321, 17.36.323, 17.36.605, 17.36.610, 17.36.802, 17.36.914, 17.36.918, 17.38.101, and 17.38.102, and amendments to Circular DEQ-4 and Circular DEQ-20). Issue 24 at page 1861 of the 2023 MAR.

Litigation Accountability

DEQ is committed to maintaining transparency regarding litigation activities.

To fulfill our commitment to transparency and accountability, DEQ provides litigation updates on this page, including:

Cases where DEQ prevailed in court
Case trends
Cases where DEQ incurred attorney fees/costs

For complete court filings, opinions, and orders, please contact the respective County District Court or Montana Supreme Court.

Cases Prevailed

Case information where DEQ prevailed in court

Case Name	Court	Case Number
Shepherd Landfill	Montana Thirteenth Judicial District Court Yellowstone County	DV-24-732
Yellowstone MS4 *On Appeal Court: Supreme Court Case No.: DA 25-0710	Montana Thirteenth Judicial District Court Yellowstone County	DV-24-80
Protect the Clearwater	Board of Environmental Review of Montana	BER 2023-02 OC
AM5	Board of Environmental Review of Montana	BER 2022-05 SM
Big Hole River	Montana First Judicial District Court Lewis & Clark County	BDV-25-265
Yellowstone Club	Montana Eighteenth Judicial District Court Gallatin County	DV-24-828
Signal Peak AM6	Montana Thirteenth Judicial District Court Yellowstone County	DV-24-1218
Rosebud AM5 WQ	Montana Sixteenth Judicial District Court Rosebud County	DV-23-14

Case Trends: Constitutional Challenge

Case information for constitutional challenges

Case Name	Court	Case Number
Black Site	Montana Eighteenth Judicial District Court Gallatin County	DV-24-838
Protect the Clearwater	Montana Fourth Judicial District Court Missoula County	DV-25-677
Friends of the Jocko	Montana Twentieth Judicial District Court Lake County	DV-25-18
Coal Minor Revision	Montana First Judicial District Court Lewis & Clark County	BDV-25-736
Gallatin Canyon Area Pipeline Project	Montana Eighteenth Judicial District Court Gallatin County	DV-25-1847
Quarry II	Montana Eighteenth JudicialDistrict Court Gallatin County	DV-25-956
Held v. State 2.0	Montana First Judicial District Court Broadwater County	DV-26-07

Attorney(s) Fees/Costs

Case information for attorney(s) fees and costs

Case Name	Court	Case Number
AM4	Montana Sixteenth Judicial District Court Rosebud County	DV-24-732
Held v. State *On Appeal Court: Montana Supreme Court Case No.: DA 23-0575	Montana First Judicial District Court Lewis & Clark County	CDV-2020-307

Table of Contents (Title 17)

Statutes

Cases Prevailed

Case Trends: Constitutional Challenge

Attorney(s) Fees/Costs

Contact Us

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Notices