Grease trap license in Colorado and the real paper path

Last updated 2026-08-19

Do you need a license for a grease trap in Colorado?

No. Colorado doesn't issue a standalone grease trap license. What people mean by a grease trap colorado license is usually other paper. You need a plumbing permit and a licensed plumber for the install. You need the local FOG registration or an OWTS permit for the use. The State Plumbing Board licenses the person who sets the device. Your city or sanitation district polices what you pour down it. ^[7][8]

That split surprises people who moved from a state with one FOG office. Colorado puts water quality in the Colorado Department of Public Health and Environment. It puts the trade license in the Department of Regulatory Agencies. Cities and sanitation districts run the day-to-day interceptor rules because they own the pipes. ^[4][2]

Federal law sits under all of it. Publicly owned treatment works have to keep solid and viscous wastes from blocking the system. 40 CFR 403.5(b)(3) requires POTWs to prohibit "Solid or viscous pollutants in amounts which will cause obstruction to the flow in the POTW resulting in Interference." Kitchen grease is the viscous pollutant inspectors have in mind. ^[1]

So you do need legal permission. You just won't find a form titled Grease Trap License on a Colorado state website. If a salesperson says they can pull the state grease trap license for you, ask which statute they mean. I'd hang up.

Opening a kitchen? Start with two calls. Call the building department that issues plumbing permits at that address. Call the wastewater utility or county health department for the same address. Those two desks rarely share a lobby. They also rarely accept each other's forms.

People comparing states can see how different the paper path is in grease trap license in California and grease trap license in Arizona. Colorado is closer to a local-utility model than a single state card.

Who issues grease trap permits in Colorado if the state does not?

Permits come from the city or county building department for the install, and from the wastewater utility or county health department for the use. CDPHE oversees pretreatment and on-site systems at the state level, but it doesn't stamp your interceptor the way a local inspector does. Confirm the current form names with the desk that will walk the site. ^[4][10]

The layers don't merge. Keep them straight.

Layer	Who	What they actually issue
Federal pretreatment	EPA under 40 CFR 403	Standards the treatment plant must enforce
State water	CDPHE, Regulation 61 and Regulation 43	Discharge framework and the OWTS rule
State trade	State Plumbing Board, C.R.S. Title 12, Article 155	Plumber licenses and the plumbing code
Local	City building plus the utility, or county health	Plumbing permit, FOG file, or OWTS permit

Federal pretreatment rules in 40 CFR Part 403 tell large treatment plants they must run a program when commercial waste can pass through or interfere with treatment. 40 CFR 403.8(a) applies those program requirements to POTWs "with a total design flow greater than 5 million gallons per day (mgd) and receiving from Industrial Users pollutants which Pass Through or Interfere with the operation of the POTW." Colorado writes the discharge-permit piece into Regulation 61, the Colorado Discharge Permit System. ^{[2][3][5][14]}

The State Plumbing Board writes trade rules in 3 CCR 720-1 and issues master, journeyman, and residential plumber licenses under C.R.S. Title 12, Article 155. That board doesn't size your interceptor. It doesn't set your pump-out schedule either. ^[6][7]

Local building departments issue the plumbing permit and inspect the set. Local utilities write FOG rules for food service shops on their sewers. Denver's industrial pretreatment program, Metro Water Recovery's industrial pretreatment program, and city programs in places like Boulder all sit in this layer. ^[12]

County health departments issue OWTS permits when the kitchen is on a septic tank. That path lives in Regulation 43. ^[9]

If two offices give you different interceptor sizes, get both answers in writing. Don't guess which one wins. Design to the inspector who can fail the final.

What plumbing license do you need to install a grease trap in Colorado?

You need a Colorado plumber license in the class that fits the job (residential, journeyman, or master) to install or relocate a grease interceptor. The work is plumbing under C.R.S. Title 12, Article 155 and the State Plumbing Board rules in 3 CCR 720-1. Confirm the current license class and permit path with the board and the local building department. ^[7][6][8]

A master plumber is the person who normally pulls the permit. A journeyman does the pipe work under that structure. An apprentice needs supervision. I wouldn't let a general contractor drop the tank in without a plumbing permit. Inspectors notice.

The statute also creates limited exemptions. Some property owners can do certain work on their own property. A commercial kitchen is a bad place to test that exemption. If the building is leased, you don't own it. If the work ties into the sanitary sewer, the city still wants a permit. Confirm any exemption in writing with the State Plumbing Board before you open a trench. ^[7][8]

Installation isn't the same job as pumping. A hauler who only pumps and hauls may not need a plumber card. They may need a completely different local registration. Don't mix the two files.

If you're still mapping the whole business, read how to start grease trap in Colorado next. The license question is only the install slice.

Fees for plumber applications change. I won't quote a number I can't pin to today's board fee schedule. Look at the Division of Professions and Occupations plumbing page and confirm before you write a check. ^[8]

How do Denver and other Colorado cities regulate grease traps?

Denver metro does not use one shared grease trap form. Denver runs an industrial pretreatment program through its wastewater group. Metro Water Recovery runs industrial pretreatment for a large share of metro treatment capacity. Nearby cities such as Boulder publish their own FOG program pages. Each one can demand a different interceptor style, sample port, or pumping record. ^[12]

Call the utility that bills sewer at the address, not a friend in another suburb. Aurora is not Denver. Lakewood may sit in Metro Water Recovery's world and still have city plumbing permits. The building permit and the FOG registration are different counters.

I see people buy a small under-sink unit for a full-service grill because the box said grease trap. Plenty of Colorado utilities want an outdoor gravity interceptor for that load. The cheap indoor unit then becomes scrap. Get the utility's sizing method in an email first.

Outdoor tanks on the Front Range need thought about freeze, traffic lids, and a spot where a pumper truck can actually sit. A tank under the only dumpster pad is a headache you'll pay for on every service visit.

Other state writeups help only as contrast. Grease trap license in Alaska is a different climate and a different agency map. Don't copy an Anchorage plan onto a Denver alley.

How much does a grease trap cost in Colorado?

There is no official Colorado price for a grease trap. Installed cost follows the device type, the digging, the plumber, and the local permit fee. Confirm today's permit fee on the city or county fee schedule that will inspect the work. Confirm the interceptor spec with the utility before you order steel or concrete.

Nobody publishes a Colorado-wide interceptor price series. The closest honest method is local plumber quotes against a utility spec.

Cost piece	Who sets it	How to confirm
Interceptor unit	Manufacturer and the plumber's quote	Written quote for the spec the utility named
Install labor	Licensed plumber	Bid that includes permit pulling
Plumbing permit	City or county building department	That office's current fee schedule
FOG or OWTS paper	Utility or county health	Their published form and fee list
Pumping	Hauler and the receiving plant	Contract plus an approved disposal site

Cost piles up in pieces. The interceptor itself. Excavation and bedding. Inlet and outlet piping. A sample port if the utility wants one. Traffic control if you cut a driveway. The plumbing permit. A possible FOG registration fee. Then the pumping contract for the life of the kitchen.

Waste of money: a hydromechanical unit the utility will reject. Also a huge gravity tank for later expansion that the site can't pump because the truck can't reach it. Pay for access, more than gallons.

Used tanks are tempting. Inspectors can still fail an old interceptor with a rotten baffle or no sample tee. If you buy used, budget for the same permit and inspection as new.

For a side-by-side of how another state splits costs and boards, grease trap board in Arizona is a useful contrast, not a template.

How long does a grease trap take in Colorado?

Colorado doesn't publish a statewide clock for grease trap work. Permit review, inspection slots, and utility plan checks all sit with local offices. Confirm current turnaround with the building department and the FOG or OWTS desk for that address. Nobody can honestly promise you a date from a state chart.

Field time is a different question. Swapping an indoor hydromechanical interceptor can be a one-day plumbing job plus the inspection. Setting an outdoor gravity interceptor is civil work. Locate the utilities. Saw-cut. Excavate. Set. Connect. Inspect. Backfill. Weather stalls concrete and open holes. Spring thaw and midwinter both make Front Range digging slower.

The paper can take longer than the shovel. Some cities treat FOG registration as a short form. Others want drawings, a menu, fixture counts, and a hauler contract before they sign off. A restaurant already open and replacing a failed tank is not the same queue as a new build.

I would not schedule the health inspection or the opening party on the same week you hope the plumbing final happens. Leave slack. Reinspection after a fail adds another visit.

If a contractor guarantees two days, permitted and passed, anywhere in Colorado, they're selling. Permits are local. ^[8]

People asking the same timing question in other states hit the same wall. See how to start grease trap in Arizona for another local-permit model.

What size grease interceptor does Colorado require?

Colorado has no single statewide gallon chart for grease interceptors. Sizing comes from the plumbing code the State Plumbing Board has adopted (the International Plumbing Code, with Colorado amendments) and from the local utility's FOG rules. Confirm which edition and which local amendment apply at the address. ^[6][8]

Utilities size by different methods. Drainage fixture units. Seating. Menu and hours. A dishwasher and a wok line are not a sandwich shop. Gravity interceptors and hydromechanical interceptors are not interchangeable just because both get called grease traps.

Indoor hydromechanical units are rated in gallons per minute and grease storage. Outdoor gravity tanks are rated in gallons of volume. If your utility says gravity, a GPM rating will not talk them out of it.

Ask for the written sizing worksheet. Do the math in that worksheet. Then buy that tank. Arguing from a manufacturer's brochure at final inspection is a weak plan.

Sample tees, cleanouts, and traffic-rated lids are part of sizing in the real world. A correctly gallon'd tank with no access is still a fail.

If the kitchen later adds a fryer, the old calculation is stale. Tell the utility before the new equipment ships.

What paperwork do you keep after the grease trap is installed?

After the tank is in, you keep the paper that proves it is sized, installed, and pumped. Typical file: plumbing permit and final, interceptor cut sheet, as-built location, FOG registration or OWTS permit, hauler contract, pump manifests, and a log of dates. Local programs vary. Confirm the retention period with the utility or county health department. ^[12][9]

Manifests matter when a blockage happens two streets down. The utility will ask who pumped you, when, and where the waste went. A pile of unmarked invoices is better than nothing. A consistent manifest is better than a pile.

Want that file in one binder? GreaseTrapPath sells a $199 one-time Interceptor + Manifest Kit. It is optional. Colorado utilities do not require that kit. A cheap folder works if you actually put the tickets in it. If your staff won't fill a log, don't buy a nicer log.

Don't let the hauler be the only one with records. Companies sell, drivers change, and PDFs vanish. Keep your own copies on site and off site.

Training the night crew not to dump fryer oil in the sink will save you more than any form. The paper documents the tank. It doesn't stop a prep cook with a 5-gallon bucket.

Some cities ask for photos of the open interceptor at pump-out, showing the 25 percent layer some programs use as a trigger. If your utility wants photos, put that in the hauler contract. Confirm the percentage they use. It is a local rule, not a Colorado statute.

Do grease trap pumpers need a separate Colorado license?

A pumper in Colorado is not licensed by the State Plumbing Board just for pumping. Plumbing licenses cover install and repair of the piping system. Hauling grease-trap waste is a transport and disposal job. Cities and receiving facilities set most of the pumper rules. Confirm whether your city keeps an approved hauler list. ^[7][4]

The receiving end is the real gate. A wastewater plant, a renderer, or a transfer facility has to accept the load. If your driver can't name the disposal site, don't hire them.

Some loads go to rendering. Some go to a receiving station. Dumping interceptor waste on a field or in a ditch is how you buy a water-quality case under the same Colorado discharge rules that sit in Regulation 61 and the Water Quality Control Act. ^[5][15]

Ask the hauler for proof of where the last several loads from restaurants like yours went. Ask if they are on the city's list. Price-only bidding is how grease ends up in a storm inlet.

If you also want to install tanks, that's a plumbing business. If you only pump, don't pay for a master plumber exam you don't need. Spend the time on disposal contracts and local registrations.

Grease trap license in Alabama shows another state's split between trade cards and hauler rules. Use it as a comparison, then follow Colorado desks.

What if the kitchen is on a septic system instead of city sewer?

If the kitchen is on a septic system, you leave the city FOG program and enter county OWTS permitting. Colorado's on-site rules live in Regulation 43 (5 CCR 1002-43). County health departments issue the permits. CDPHE writes the state regulation. Confirm interceptor and tank requirements with the county that will sign the OWTS permit. ^[9][10]

Commercial kitchens on septic in Colorado are permitted by county health departments under Regulation 43 (5 CCR 1002-43). That sentence is the whole path for off-sewer sites. It is not a grease trap license. It is the on-site wastewater regulation. ^[9]

Commercial kitchens put a lot of grease into a septic tank. Counties often want a grease interceptor upstream so the drain field doesn't clog. That interceptor is still plumbing. You can still need a licensed plumber and a building permit on top of the OWTS permit. Two counters again.

I would not reuse a tiny under-sink unit and hope the county looks away. Drain-field replacement in Colorado mountain or clay soils is a brutal bill. The interceptor is cheaper.

OWTS design usually needs a person the county recognizes. That's a different roster than the city FOG coordinator. Bring the menu, fixture list, and peak covers.

If you later connect to city sewer, the OWTS file doesn't automatically become a FOG file. You'll start over with the utility.

What happens if you skip a grease trap in Colorado?

Skipping a required interceptor, or running one as a dumpster, can bring a notice of violation from the utility or the county. The federal hook is still 40 CFR 403. Pretreatment programs exist because waste that interferes with a POTW is a Clean Water Act problem, bigger than a clogged sink. Colorado's discharge-permit framework is Regulation 61. ^{[1][14][5][4]}

40 CFR 403.8(a) requires pretreatment programs at POTWs with a total design flow greater than 5 million gallons per day when industrial users can pass through or interfere. That 5 mgd threshold is why big Front Range plants run FOG programs even though Colorado has no grease trap license. ^[14]

What you actually see on the ground is more ordinary. A sewer backup. A camera video full of grease. A bill for cleaning the main. A requirement to install the tank you deferred, now on a deadline. Repeat problems can escalate. I have no honest statewide fine table to quote. Penalty amounts are local or case-specific. Confirm the enforcement section in your utility's rules.

Health departments care when grease hits the dining room floor or a backflowed drain. That's a different inspector than the pretreatment person.

If a main backs up into a neighboring basement, you can face more than a utility letter. Don't wait for that.

Keep the tank pumped. Teach the dish pit. Those two habits beat any argument after the fact.

What should you confirm with the local board before you buy anything?

Before you spend money, confirm six facts in writing with the office that will inspect you. Sewer or septic. Required interceptor type. Sizing method. Who may install it. What pumping interval or 25 percent rule they use. What records they want on site. Then confirm the current permit fee on that office's fee schedule. Do not use a blog number, including this one, as the fee.

Get the utility name off a sewer bill if the kitchen already exists. New builds should ask the civil engineer which district they platted into. Metro Water Recovery is not the same as Denver's city program, even when both touch the metro area. ^[12]

I'd skip any contractor who will not write the permit number on the bid. I'd also skip a tank vendor who has never asked which utility serves the lot.

A starting checklist is only a way to organize those calls. GreaseTrapPath is an independent publisher, not a law firm and not a service company. The checklist doesn't replace the board.

For the opening sequence after the license question, use how to start grease trap in Colorado. For another state's board map, how to start grease trap in California shows a heavier state overlay.

Frequently asked questions

Do you need a license for grease trap in Colorado?

Colorado doesn't issue a single grease trap license. Installation is plumbing under C.R.S. Title 12, Article 155, so a licensed plumber and a local plumbing permit are the usual path. Food service on city sewer also needs the local FOG or pretreatment registration. Septic sites go through county OWTS permitting under Regulation 43. Confirm the exact forms with the building department and the utility or county health desk.

How much does grease trap cost in Colorado?

Nobody publishes a statewide grease trap price for Colorado. Installed cost is the tank, digging, plumber labor, the local plumbing permit, and any FOG or OWTS fee. Those fees change by city and by year. Get written plumber quotes against the interceptor spec your utility or county already named. Confirm current permit fees on that office's fee schedule.

How long does grease trap take in Colorado?

There is no Colorado-wide processing time. A simple indoor swap can be a day's plumbing plus inspection. An outdoor gravity interceptor needs excavation, a plumbing permit, and a utility or OWTS review, which can stretch longer than the digging. Weather and reinspection add time. Confirm current review times with the building department and the FOG or county health desk.

Is a grease interceptor the same as a grease trap in Colorado?

People use the words as if they match. Inspectors often don't. A hydromechanical unit (often called a trap) is rated in gallons per minute. A gravity interceptor is a large-volume tank, usually outdoors. Your utility's FOG rules and the adopted plumbing code decide which one is legal at that address. Confirm the device type in writing before you order.

Can I install my own grease trap in a Colorado restaurant?

Treat commercial install as licensed plumbing. C.R.S. Title 12, Article 155 and 3 CCR 720-1 put that work under the State Plumbing Board. Limited owner exemptions exist in the statute, but a leased restaurant is a poor place to test them. The city still wants a plumbing permit for sewer tie-ins. Confirm any self-install idea with the board and the building department first.

Who inspects grease traps in Denver?

Expect two different inspectors. A city plumbing inspector signs the install against the plumbing permit. Denver's industrial pretreatment program (and, for much of the metro treatment system, Metro Water Recovery) can review FOG compliance after the kitchen is operating. Confirm which wastewater authority bills the address. A Denver tap and a suburban tap are not the same desk.

How often do I have to pump a grease trap in Colorado?

Colorado has no single statewide pump interval. Many utilities use a set number of days, a 25 percent grease-and-solids rule, or both. That percentage is a local program rule, not a state license condition. Read the FOG packet for your utility or the OWTS permit for a septic site. Put the interval into the hauler contract so you are not guessing.

Do food trucks need a grease trap license in Colorado?

There is still no statewide grease trap license for trucks. Most health departments want the truck tied to a commissary, and the commissary's interceptor is the device that matters. Grease stored on the truck still has to go to a legal receiver, not a storm inlet. Confirm commissary and wastewater rules with the local health department and the commissary's utility.

What is a FOG program in Colorado?

FOG means fats, oils, and grease. A FOG program is the local utility's way of keeping that waste out of the sewer, using interceptor rules, pumping records, and inspections. It exists because 40 CFR 403 tells treatment plants to stop viscous wastes that cause interference. CDPHE oversees pretreatment at the state level. The forms you fill out are almost always local.

Does CDPHE issue grease trap permits?

Not as a named grease trap permit for a city-sewer restaurant. CDPHE oversees pretreatment and writes Regulation 43 for on-site systems. County health departments issue OWTS permits. City building departments issue plumbing permits. Utilities run FOG registration. Call CDPHE if you need the state rule. Don't expect them to stamp your interceptor lid.

What license does a grease trap pumper need in Colorado?

Pumping is not a State Plumbing Board card by itself. The hard part is legal transport and a receiving facility that will take the load. Some cities keep approved hauler lists. Dumping interceptor waste on the ground can become a Regulation 61 and Water Quality Control Act problem. Confirm local registration and ask where the last loads actually went.

Are under-sink grease traps legal in Colorado?

Sometimes, for a low-flow shop, if the adopted plumbing code and the local utility both allow a hydromechanical unit. Full-service kitchens are often told to install an outdoor gravity interceptor instead. Legal in one suburb can be a fail two miles away. Get the device type from the utility that owns the sewer, then buy that unit.

What happens if my grease trap overflows in Colorado?

Call your plumber and your hauler, then tell the utility if product hit a drain, alley, or storm inlet. Overflows can trigger cleanup bills, a notice of violation, and a demand to resize or pump more often. If sewage backed into the dining room, the health department may get involved too. Keep manifests. They are the first thing an inspector asks for.

Do I need a grease trap for a coffee shop in Colorado?

It depends on fixtures and the local definition of a food service establishment. A shop with only espresso and sealed pastries may be treated differently than one with a dishwasher, grill, or open food prep. The utility or county health department decides, not a statewide grease trap license. Ask before you build the dish pit.

Sources

1. eCFR, 40 CFR 403.5 National pretreatment standards: Prohibited discharges: POTWs must prohibit solid or viscous pollutants that obstruct flow and cause Interference
2. U.S. EPA, National Pretreatment Program: EPA describes the national pretreatment program that local POTWs implement for commercial and industrial discharges
3. U.S. EPA, Introduction to the National Pretreatment Program (EPA-833-B-11-001, 2011): EPA's 2011 manual documents the federal-state-local pretreatment framework Colorado utilities operate inside
4. Colorado Department of Public Health and Environment, Pretreatment: CDPHE administers pretreatment oversight for Colorado
5. Colorado Secretary of State, 5 CCR 1002-61 Regulation 61 Colorado Discharge Permit System: Regulation 61 is Colorado's discharge permit system regulation
6. Colorado Secretary of State, 3 CCR 720-1 State Plumbing Board rules: 3 CCR 720-1 contains the State Plumbing Board rules that govern licensed plumbing work
7. Colorado General Assembly, Colorado Revised Statutes 2023 Title 12: C.R.S. Title 12, Article 155 is the state plumber licensing statute
8. Colorado Division of Professions and Occupations, Plumbing Laws, Rules and Policies: The State Plumbing Board publishes the laws, adopted code, and rules that apply to plumbing installations
9. Colorado Secretary of State, 5 CCR 1002-43 Regulation 43 On-site Wastewater Treatment System Regulation: Regulation 43 is Colorado's on-site wastewater (septic) regulation used by county health departments
10. Colorado Department of Public Health and Environment, On-site Wastewater Treatment Systems: CDPHE hosts the state OWTS program that counties implement under Regulation 43
11. Metro Water Recovery, Industrial Pretreatment: Metro Water Recovery operates an industrial pretreatment program for a large share of Denver-metro treatment capacity
12. eCFR, 40 CFR 403.8 Pretreatment Program Requirements: POTWs over 5 mgd that receive interfering industrial-user pollutants must establish a pretreatment program
13. Colorado General Assembly, Colorado Revised Statutes 2023 Title 25: Title 25 contains the Colorado Water Quality Control Act that frames state discharge authority