Montana Grease Trap Regulations (2026)
Everything a Montana restaurant or commercial kitchen needs to know about grease trap requirements: who regulates it, how often you must clean, what permits and registration you need, what records to keep, and what violations actually cost. Citations link to the official source so you can verify every claim — and show your inspector you did.
Montana Requirements at a Glance
| Cleaning frequency | No statewide interval — set by municipal programs and trap size/usage. Missoula requires total removal of interceptor contents at each service. |
| State regulator | Montana Department of Environmental Quality (DEQ) |
| Governing regulation | ARM 17.50.815 (Grease Trap Wastes); Solid Waste program authority under Montana Code Annotated Title 75, Chapter 10 |
| Manifest required | Yes — licensed pumpers keep Land Application and Wastewater Treatment summary logs for each load; disposal sites must be DEQ-approved (ARM 17.50.815) (source) |
| Licensed hauler required | Yes — Montana Septic Tank Pumper License (DEQ Solid Waste Management Section) — the SAME license covers grease trap hauling; expires Dec 31 annually, $125 renewal (source) |
| Penalties | Operating as a grease trap hauler without a valid Montana DEQ Septic Tank Pumper License can bring DEQ-assessed penalties (specific amounts not published). (source) |
Who Regulates Grease Traps in Montana
At the state level, Montana Department of Environmental Quality (DEQ) (program page) oversees FOG (fats, oils, and grease) discharge; the governing rule is ARM 17.50.815 (Grease Trap Wastes); Solid Waste program authority under Montana Code Annotated Title 75, Chapter 10. Day-to-day enforcement — inspections, cleaning intervals, fines — usually happens through your city or county sewer utility's pretreatment program, which can set stricter rules than the state.
Hauler Licensing & Verification
Montana requires grease trap waste to be transported by licensed/registered haulers under Montana Septic Tank Pumper License (DEQ Solid Waste Management Section) — the SAME license covers grease trap hauling; expires Dec 31 annually, $125 renewal. (source) Before signing a contract, verify the hauler's registration on the official lookup — it takes two minutes and it's the single best protection against illegal-dumping liability landing on you.
Manifests & Record Keeping
- Collect a signed manifest (licensed pumpers keep Land Application and Wastewater Treatment summary logs for each load; disposal sites must be DEQ-approved (ARM 17.50.815)) at every service — date, volume removed, hauler license, disposal facility. (source)
- Track everything in one place: free maintenance log and cleaning schedule template.
City Programs in Montana
Cities run their own FOG programs and often set stricter rules than the state:
Billings
- Program: City of Billings wastewater/sewer pretreatment
- Ordinance: Billings Municipal Code §26-604; Ordinance No. 13-5603
- Permit: Food establishments on public sewer must have an approved grease system (trap or interceptor)
Missoula
- Program: City of Missoula FOG Sector Control Program
- Ordinance: Missoula Municipal Code §13.07.260, §13.07.410(C)
- Cleaning frequency: Total interceptor contents removed at each cleaning; frequency by facility usage, with a logbook maintained
- Permit: Individual Wastewater Discharge Permit via Missoula Public Works; variances via the Industrial Interceptor Review Committee
Worth Knowing in Montana
Montana folds grease hauling into its septic program — grease trap haulers need the same state DEQ Septic Tank Pumper License required for septic pumping, with no separate grease credential. ARM 17.50.815 treats grease trap waste as a regulated solid waste requiring DEQ-approved disposal sites. Missoula's FOG Sector Control Program requires a gravity interceptor (not an under-sink trap) for all new and remodeled food facilities.
Frequently Asked Questions
How often must grease traps be cleaned in Montana?
No statewide interval — set by municipal programs and trap size/usage. Missoula requires total removal of interceptor contents at each service. Your city's FOG program may require more frequent service — and regardless of the legal interval, clean before fats, oils, and grease reach 25% of trap capacity.
Do I need a manifest for grease trap cleaning in Montana?
Yes. Get a signed manifest (licensed pumpers keep Land Application and Wastewater Treatment summary logs for each load; disposal sites must be DEQ-approved (ARM 17.50.815)) from the hauler at every service and keep it at least 3 years. It's the document inspectors ask for first.
What are the penalties for grease trap violations in Montana?
Operating as a grease trap hauler without a valid Montana DEQ Septic Tank Pumper License can bring DEQ-assessed penalties (specific amounts not published). Enforcement is usually municipal, so your city's fine schedule controls — the fastest way to stay off it is a maintained cleaning schedule and complete records.
Can anyone pump my grease trap in Montana?
No — use a licensed/registered hauler (Montana Septic Tank Pumper License (DEQ Solid Waste Management Section) — the SAME license covers grease trap hauling; expires Dec 31 annually, $125 renewal). If your hauler dumps illegally, the paper trail you kept is your protection. Verify registration on the official lookup linked above.
Do I need a permit for a grease trap in Montana?
In most Montana cities, yes — food service establishments must register with, or get a permit from, the local FOG / pretreatment program before discharging grease trap waste to the sewer. The exact permit and registration requirements vary by city; the major-city programs are listed above, and your local sewer authority has the specifics for your address.
Next Steps
- Find grease trap cleaning companies in Montana
- Run the Montana-adapted compliance checklist
- Put manifests and pricing in writing (free template)
Official Sources
- https://deq.mt.gov/
- https://rules.mt.gov/gateway/RuleNo.asp?RN=17.50.815
- https://deq.mt.gov/twr/Programs/septic-tank
- https://www.ci.missoula.mt.us/DocumentCenter/View/1033/Municipal-Code-Title-13-Public-Services
- https://www.billingsmt.gov/156/Ordinances
This guide summarizes official sources for general information and is not legal advice. Rules change — confirm requirements with Montana Department of Environmental Quality (DEQ) and your local FOG program.
Montana Grease Trap Costs & Rules by City
City-level pricing, cleaning frequency and permit requirements:
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