Subdivision Review Program

The Department of Environmental Quality Subdivision Program reviews divisions of land comprising  less than 20 acres, as well as condominiums and recreational camping vehicle and mobile home parks, regardless of the size of the parcel where they are located.  This review under the sanitation in subdivisions regulations is limited to sanitation facilities, including the water supply, sewage disposal, solid waste disposal, and storm drainage systems.  Proper design and location of these facilities is necessary to protect the quality of water for public water supplies, domestic uses, and other beneficial uses, including uses related to agricultural, industry, recreation, and wildlife.

Subdivisions are reviewed prior to creating the parcels to assure that adequate sanitation facilities can be constructed, operated, and maintained to support each parcel. Planning ahead for proper design and location of the facilities helps protect both our surface and ground water in Montana.  Design manuals have been developed to provide standards for wastewater treatment systems, water supply development, and storm drainage systems. The regulations also set out minimum separation distances between water supply sources and potential contamination sources such as wastewater treatment systems, surface waters, and floodplains.

The regulations and subdivision review are structured to prevent pollution problems through the proper design, location, operation, and maintenance of sanitation facilities.



Subdivision News

The new DEQ Stormwater Circular (DEQ-8) will be effective August 11, 2018. The Department has scheduled a number of training's on the new circular and updated rules at various locations across the state:

• Missoula on August 29th, 1 PM to 4 PM – Missoula County Environmental Health Office, 301 West Alder Street, Missoula MT 59802

• Kalispell on August 30th, 9 AM to Noon – Flathead County Environmental Health Office, South Campus Conference Room, 1035 1st Avenue West, Kalispell, MT 59901
• Bozeman on September 11th, 1 PM to 4 PM – Gallatin County Courthouse Community Room (Third Floor), 311 West Main, Bozeman, MT 59715
• Billings on September 14th, 1 PM to 4 PM – Billings Public Library, 123 510 North Broadway, Billings, MT 59101

• MEHA in Helena on September 19th, numerous trainings on DEQ related topics

Training Presentation


Proposed Rule and Circular DEQ-8 Changes

MAR 17-392 pro-arm

DEQ-8 Subdivision Storm Water Drainage

DEQ-8 Simplified Plan Spreadsheet

DEQ-8 Standard Plan Spreadsheet

DEQ-8 IDF Spreadsheet