Last updated 2026-08-19
TL;DR
Colorado does not sell a statewide grease trap license. You pay for the interceptor, a licensed plumber, local plumbing or wastewater paper, and first year pumping under your city FOG rules. Indoor units often land in the low thousands installed. Outdoor gravity tanks cost more once excavation starts. There is no official state average. Confirm sizing and fees with your utility and the plumbing board before you buy.
How much does a grease trap cost in Colorado?
A grease trap in Colorado runs from a few hundred dollars for a small indoor box (plus plumber time) to well into five figures for an outdoor gravity interceptor once you add excavation, concrete, and traffic-rated lids. The state publishes no official average. Your city and the dirt under the parking lot move the number more than any national blog post ever will.
The sticker on the tank is the least honest part of any quote. The number that matters is installed and accepted. That means a licensed plumber, a plumbing permit, any wastewater or FOG review your utility wants, saw-cutting or excavation if the unit sits outside, bedding, piping, a sample tee if the district asks for one, and the first pump-out so you have a clean baseline. Indoor hydromechanical units (the under-sink or in-floor boxes rated in gallons per minute) are the cheap end of the hardware. Outdoor gravity interceptors are a civil job that happens to include a tank.
Nobody has a clean Colorado-wide price study. National consumer sites toss around wide bands, then mix homeowner grease traps with restaurant interceptors. Ignore those as bids. Get three contractor numbers in the same city, same size, same lid rating. A Denver alley job is not a gravel lot in an unincorporated county. Labor tracks licensed plumbing wages, and the Bureau of Labor Statistics publishes the federal median for plumbers, pipefitters, and steamfitters in its Occupational Outlook Handbook. Read the current median there before you decide a labor line looks drunk [14].
Comparing states for a multi-unit concept? Skim what grease trap cost in Arizona or grease trap cost in California looks like, then throw the comparison out. Those pages will not pay your Denver inspector. Hardware catalogs look similar. The paper and the dirt do not.
My rule on money: pay for the size the local utility will accept, installed by someone who has pulled that permit on that street. Do not pay for a shiny European box a salesman swears is "code plus." Code is whatever Colorado has adopted and whatever your city wrote on top. Confirm both.
Do you need a license for a grease trap in Colorado?
No. Colorado issues no statewide grease trap license. Installing one is plumbing, and plumbing takes a license from the state plumbing board under Title 12, Article 155 of the Colorado Revised Statutes [5][7]. If you serve food to the public, you need a retail food establishment license under Colorado's retail food rules, which CDPHE writes and local public health agencies issue [8]. If you pump other people's interceptors, you need the hauler and disposal approvals your county and the receiving plant actually give you. Those are different desks. Do not let a course seller mash them into one fictional card.
The install side is the part people get backwards. A restaurant owner does not become a plumber by buying a tank. C.R.S. Title 12, Article 155 is the plumber statute. The Department of Regulatory Agencies plumbing page is where you confirm who may pull the permit and which license class covers the work [5][6]. I would not let an unlicensed handyman drop a 1,000 gallon can in a city right-of-way and hope the inspector is in a good mood.
The food side is separate paper. CDPHE's retail food program is the state frame. Your county or city health department is the counter you actually stand at [8]. They care that the kitchen can be cleaned and that wastewater goes where it should. They will send you to the utility for the interceptor details more often than they will size the tank themselves.
The pump-out side is a third stack. Interceptor waste is not the same as a jug of fryer oil you sell to a renderer. The plant that takes the slurry sets the rules. Metro Water Recovery runs industrial pretreatment for a large piece of the Denver metro area, and they are a real desk, not a vibe [11]. County health still matters if the building is on an on-site system under Regulation 43 [9].
Someone tries to sell you a "Colorado grease trap operator license"? Ask for the statute number. Then call the board they named. If the board stares at you, you almost bought a class.
How long does a grease trap take in Colorado?
The tank can go in during a kitchen build in a day or two once the permit is in hand. Outdoor gravity interceptors take longer because of excavation, bedding, inspections, and sometimes traffic control. Permit review is local. I will not quote a state processing clock because there is not one. Ask the building department that will stamp the drawings, then add weather and inspector load.
New construction is the easy version. The interceptor is on the plumbing set. The plumber coordinates with the general contractor. You still wait on plan review like every other fixture. Tenant-improvement jobs in old Denver or Colorado Springs buildings drag when nobody knows where the old line runs. I have seen the saw-cut take longer than the set. Budget time for that discovery. Do not promise a landlord a Friday open based on a catalog lead time.
A site on a septic system puts you in Regulation 43 territory and on the county health department's calendar, more than the city plumber's [9]. That can be slower. It can also be simpler if the county already knows the designer. Confirm. Do not assume Front Range city timing applies in a mountain county.
First acceptance is not the end of the clock. FOG programs want a maintenance plan, a pumping interval, and a place to keep manifests. That paper can take longer than setting the tank if you ignore it until opening week. Build the logbook while the concrete cures.
What size grease trap does Colorado actually expect?
Colorado publishes no statewide gallon chart for every restaurant. Sizing sits in the plumbing code the state plumbing board has adopted, plus whatever your wastewater utility added [6]. Indoor units are usually picked by flow rate in gallons per minute and certified to standards such as PDI-G101. Outdoor gravity interceptors are usually picked in gallons of holding volume, often from a fixture-count or menu formula the local program likes.
This is where people waste money. They buy a 20 gpm under-sink box for a full-service grill because it was in stock, then fail the first inspection. Or they let a vendor drop a 2,000 gallon vault in a parking lot when the utility would have accepted a smaller approved unit with a tighter pump schedule. Oversizing is not automatically virtuous. It is more tank to pump, more lid to maintain, and more hole to dig.
Ask the utility for their sizing method in writing. Some Front Range cities point at the plumbing code and stop. Some hand you a worksheet. Metro-area industrial pretreatment programs exist because federal rules expect large plants to control what comes in [2][11]. Your job is to match their method, not a YouTube rule of thumb.
Look at grease trap cost in Idaho or grease trap cost in Illinois and you will see the same hardware families. The acceptance test is still local. Bring the cut sheet, the certification, and the sample-port detail the district wants. Leave the vibes at home.
What permits and paper sit on top of the tank price?
The tank is one line. The paper is several. A typical Colorado food service build stacks a plumbing permit for the interceptor, whatever building or excavation permit the hole needs, a retail food establishment license, and a FOG or industrial-user packet if your sewer authority runs one [5][8][11]. None of those is a "grease trap license."
Federal pretreatment rules are why the packet exists at all. 40 CFR 403.5 prohibits "Solid or viscous pollutants in amounts which will cause obstruction to the flow in the POTW resulting in interference" [1]. That sentence is why cities make you buy a box. Colorado implements pretreatment through CDPHE and the approved local programs [11]. Plants with design flow over 5 million gallons per day are the ones federal rules generally push into a full pretreatment program [2].
Walk the paper in this order. First, call the wastewater authority and ask if they have a written FOG or grease interceptor policy. Second, ask the building department how they want the interceptor shown on the plumbing set. Third, ask retail food licensing what they want to see at opening inspection [8]. Fourth, if you are on a vault or septic, open Regulation 43 with the county [9].
Do not pay a consultant to "expedite" a two-page local form unless that person has a real relationship with that counter. Most of this is filling the form the city already posted and showing up.
GreaseTrapPath sells a $199 Interceptor + Manifest Kit if you want a single place to keep the install packet and the pump tickets together. The city will not ask for our logo. They will ask for the same facts the utility already listed.
How much is first-year pumping and maintenance in Colorado?
First-year pumping is the cost people forget and then resent. Cities care about the 25 percent rule more than they care about your favorite enzyme. When grease plus solids hit about a quarter of the tank, it is time. Some programs write a default interval (often monthly or quarterly for a new kitchen) until you prove a longer cycle. I will not invent your city's interval. Read the policy they handed you [11].
Price per pump varies with tank size, access, and how far the truck is going. Downtown Denver with a lid under parked cars costs more than a wide lot off the interstate. Mountain towns add drive time. There is no state tariff. Get a hauler quote in the same zip code as the tank, and ask where the waste actually goes. If they dodge the disposal site, pick someone else.
Add lids, gaskets, and a broken cleanout to the first-year mental budget. Outdoor units collect asphalt grindings and idiots with snowplows. Indoor units collect dishwashers who discover the baffle is a shelf. Budget a service call.
Additives as a substitute for pumping are a waste of money in most FOG programs, and some cities restrict them. A bottle that promised you would never need a truck is selling you a backup into the main. Pump the tank. Keep the ticket.
Indoor hydromechanical vs outdoor gravity interceptor in Colorado?
Indoor hydromechanical interceptors are the compact boxes. They are rated in gpm, often tested to PDI-G101, and they need frequent pumping because they are small. They fit remodels and tight Denver basements. They fail when the kitchen is too big for the rating or when the dishwasher is tied in against the listing.
Outdoor gravity interceptors are the big vaults. They give you detention time. They need a hole, proper bedding, traffic lids if cars roll over them, and a path for the pumper truck. They are the default for many full-service restaurants on city sewer. They are also the jobs that blow the budget when someone forgot about groundwater, rock, or a fiber line.
Colorado winter is not a reason to panic about a buried concrete tank. It is a reason to keep risers findable after a plow berm and to spec lids that can take the load. I would not leave a shallow plastic unit in a drive lane and hope January is kind.
Pick the type the utility will accept for your menu and seating, not the type that looked cheaper on a supply-house shelf. A cheap indoor unit you replace in eight months is not cheap. An outdoor vault you cannot access without towing the owner's truck is not clever.
Who inspects grease traps in Denver, Aurora, and Colorado Springs?
Inspectors come from more than one building. The plumbing inspector looks at the install against the adopted plumbing code [6]. The wastewater or industrial pretreatment staff look at sizing, sample tees, and later at maintenance. Retail food inspectors look at whether the kitchen is operable, and they will notice a missing or overflowing interceptor [8]. On septic, county health owns more of the story under Regulation 43 [9].
Use this as a call sheet, then confirm names and emails on the live pages. Staff titles move. The desks do not.
| City or district | Desk that actually answers | What to ask |
|---|---|---|
| Denver | DOTI Wastewater Management plus Community Planning and Development for the plumbing permit | interceptor policy, sample port, who signs the FOG packet |
| Boulder | City FOG program | required device, pumping records, inspection contact [11] |
| Fort Collins | Utilities industrial pretreatment | local limits, interceptor approval, hauler rules [11] |
| Metro Denver treatment | Metro Water Recovery industrial pretreatment | whether your discharge sits in their program and what they want on paper [11] |
| Unincorporated / septic | County health plus CDPHE Regulation 43 | whether a grease interceptor is part of the OWTS design [9] |
Colorado Springs Utilities runs its own pretreatment conversation. Call them. Do not use a Denver checklist in Springs and pray.
Used to how grease trap cost in Florida or grease trap cost in Georgia cities split health and water? The split here will feel familiar. The letterhead will not.
What do Colorado haulers and manifests have to show?
A manifest is the chain of custody for the slurry. Date, address, tank size or gallons pulled, hauler name, and where it went. Your city FOG program will tell you the exact fields. Keep copies on site. Inspectors have a sense of humor about empty binders. It is not a good sense of humor.
The receiving facility sets who may dump. That may be a wastewater plant that takes FOG, a private processor, or a landfill program that takes dewatered solids. Metro-area pretreatment staff care about this because the federal program sits behind them [1][11]. Do not let a cash truck "take it somewhere." You own the waste until a lawful facility takes it.
Used cooking oil in a closed barrel is a different commodity. Do not mix fryer oil and interceptor sludge in your head or in a tote. Renderers want oil. Plants and processors that take interceptor waste want the wet, ugly stuff. Mixing them can get a load rejected. Then you pay twice.
Pump for other kitchens and you are in a small regulated business, not a side hustle with a shop-vac. County hauler rules, vehicle standards, and disposal contracts are the real license path. Confirm each piece with the county and the plant. There is no single state "grease pumper card" that replaces those calls.
What I'd actually budget if I were opening a kitchen in Colorado
I would put five buckets on one page. Hardware. Install labor and site work. Permits and utility review. First-year pumping. A contingency for the surprise in the alley. I would not publish fake dollar totals for those buckets because they move with city, size, and whether you are cutting a finished parking lot. I would get real bids into each bucket before I signed a lease that assumed a $900 miracle box.
I would hire a plumber who has closed interceptor permits in that exact city in the last year. National median plumber pay from BLS is only a sanity check on the labor line, not your bid [14]. Local shops that know the inspector save more than they charge.
I would not buy a used gravity tank unless the inspector has a path to accept it and a leak test is in the contract. I would not pre-order a unit from an out-of-state catalog until the utility signed off on the cut sheet. Lead times hurt less than a rejected model.
Rural or mountain sites on OWTS need the designer and the county in the same conversation as the kitchen planner [9]. I have watched people buy a city-style indoor unit for a lodge on a vault and then redo it. Mean way to learn Regulation 43.
Want a comparison datapoint for a second unit in another state? grease trap cost in Alabama and grease trap cost in Alaska show how fast the paper path diverges. Use them as a reminder to call the Colorado desk, not as a spreadsheet input.
What is a waste of money on Colorado grease trap jobs?
Paying for a statewide grease trap license course. It does not exist. Paying for enzyme programs that claim to replace pumping. Most FOG desks still want the truck and the ticket [11]. Paying a middleman to submit a form you can download. Buying the next size up "just because" when the utility already approved a smaller listed unit. Decorative indoor units that lack PDI or ASME listings the inspector recognizes.
Also a waste: opening without a sample tee the district asked for, then cutting finished floor to add one. Read the detail before tile goes down.
Not a waste: a plumber who has failed this inspection before and will not fail it with your money. A traffic-rated lid where cars actually park. A riser you can find after a snow storage pile moves. Photos of the open tank before backfill. Those photos settle arguments.
How do Colorado cities differ on FOG rules?
They differ more than the hardware does. Big utilities on the Front Range tend to have written FOG or pretreatment pages, inspection programs, and opinions about gravity versus hydromechanical units [11]. Smaller towns may only enforce through the plumbing permit and a complaint when the main backs up. Ski towns on small plants can be stricter than Denver because one bad kitchen is a larger share of their flow. Confirm. Do not guess from Instagram.
EPA's overflow estimates are the reason even a small town gets cranky. "EPA estimates that there are at least 23,000 to 75,000 SSOs per year" in the United States, not counting indoor backups [3]. Grease is one of the usual villains in those blockages. Your city did not invent this to annoy chefs.
Food trucks are the gray edge. Some Colorado cities want the truck tied to a commissary that has an interceptor. Some want a device on the vehicle. Some mostly care where you dump the wastewater. Ask the same retail food desk that licenses the truck [8]. Do not take advice from the guy in the next space at the brewery lot.
GreaseTrapPath is an independent publisher, not a law firm and not a hauler. Want the kit that holds interceptor cut sheets and pump manifests in one pile? It is $199 and lives at /start. The useful move is still the same. Call the plumbing board, the utility, and health. Write down what they said. Buy the tank that matches that note.
Frequently asked questions
Do you need a license for grease trap in Colorado?
No statewide grease trap license exists. Installation is plumbing under C.R.S. Title 12, Article 155, so a licensed plumber pulls that work. Food businesses still need a retail food establishment license from local public health. Haulers need county and disposal-plant approvals. Confirm each desk. Do not buy a course that pretends those are one card.
How much does grease trap cost in Colorado?
There is no official state average. Small indoor hydromechanical units plus plumber time often land in the low thousands installed. Outdoor gravity interceptors with excavation and traffic lids can run much higher, sometimes into five figures. Permits, first-year pumping, and site surprises sit on top. Get local bids for the same size and lid rating.
How long does grease trap take in Colorado?
Setting an indoor unit can take a day or two after the permit is issued. Outdoor tanks take longer because of digging, inspections, and sometimes traffic control. Plan review is local and has no statewide clock. On-site systems under Regulation 43 follow the county's calendar. Ask the department that will stamp your set.
Can I install my own grease trap in Colorado?
Only if you hold the right Colorado plumbing license for that work, or you hire someone who does. The state plumbing board, not the restaurant license, controls who may install plumbing. Homeowner exceptions that people remember from a bathroom remodel usually do not cover a commercial interceptor on a business. Confirm with DORA's plumbing page before you pick up a shovel.
How often do you pump a grease trap in Colorado?
Whenever grease and solids hit the limit your utility wrote, often around 25 percent of the tank, or on the default interval in your FOG packet. New kitchens are commonly on a short cycle until they have data. There is no single state schedule. Read the local policy and keep every manifest.
Does Denver require an outdoor interceptor?
Denver decides from the plumbing code plus Wastewater Management review, not from a blog rule. Many full-service kitchens end up with an outdoor gravity interceptor. Some smaller operations can use a listed indoor unit if the utility accepts the sizing. Ask DOTI Wastewater and the plumbing reviewer on your specific menu and fixture count.
Do food trucks need a grease trap in Colorado?
Sometimes. Many cities want the truck tied to a commissary that has a working interceptor. Others ask about onboard devices or where wastewater is dumped. Retail food licensing is the first call. The sewer authority is the second. Do not copy another truck's setup without asking both desks in that city.
What happens if I skip the interceptor?
You can fail plumbing or opening inspection, pick up a wastewater enforcement case, and pay to cut finished work later. Federal pretreatment rules already ban viscous discharges that obstruct the plant. Local FOG programs exist to keep that grease out of the main. Skipping the box to save a month of cash is how people buy two boxes.
Are grease trap permits the same in mountain towns?
No. Small plants and county OWTS programs do not copy Denver's packet. Some ski towns are stricter because one kitchen is a large share of flow. Unincorporated sites may live under Regulation 43 instead of a city FOG page. Confirm with that town's building department and the county health agency that licenses the kitchen.
Does a used interceptor pass inspection in Colorado?
Only if the local inspector will accept it and it still meets the listing, sizing, and condition they enforce. Buried tanks hide cracks and missing baffles. I would not buy used without a contract that includes inspection, a leak test, and removal if it fails. New listed equipment is boring. Boring passes.
Who hauls grease trap waste in Colorado?
Private liquid-waste haulers that the receiving facility will admit, sometimes also registered with the county. Ask your utility for a list if they keep one, then call the dump site and confirm the hauler is still welcome. Keep the manifest. A truck with no disposal ticket is not a hauler. It is a liability.
Is cooking oil the same as interceptor waste?
No. Fryer oil in a closed container is a commodity renderers buy. Interceptor slurry is mixed wastewater solids. Mixing them can get a load rejected and can violate the receiving site's rules. Separate barrels, separate tickets, separate vendors if that is how your town is set up.
How much is a plumbing permit for a grease trap in Denver?
Denver publishes building and plumbing fee schedules, and those numbers change. I will not invent this year's fee. Look up the current Community Planning and Development permit fee schedule and ask whether your interceptor is valued with the plumbing fixture set or as a separate valuation. Confirm before you write the check.
Do I need a grease trap on a Colorado septic system?
Often yes for a food service building on an on-site wastewater treatment system. Regulation 43 and the county health department control that design, not a city FOG brochure. The designer sizes pretreatment, including any grease interceptor, as part of the OWTS. Do not drop a city under-sink box on a lodge vault and assume it counts.
Sources
- eCFR 40 CFR 403.5 Prohibited discharges: Federal pretreatment rules prohibit solid or viscous pollutants in amounts that will cause obstruction to POTW flow
- eCFR 40 CFR 403.8 Pretreatment program requirements: POTWs with total design flow greater than 5 MGD that receive industrial pollutants are generally required to establish a pretreatment program
- U.S. EPA Sanitary Sewer Overflow (SSO) Frequent Questions: EPA estimates at least 23,000 to 75,000 SSOs per year in the United States
- Colorado DPO Plumbing program page: Colorado requires state plumbing licensure for plumbing work, administered by the state plumbing board
- Colorado DPO Plumbing laws, rules, and policies: The state plumbing board publishes the adopted plumbing code and the statutes that govern licensed plumbing
- Colorado Revised Statutes Title 12 (Professions and Occupations): C.R.S. Title 12, Article 155 is the Colorado plumber licensing statute
- CDPHE Retail Food program: Colorado retail food establishments are licensed under state retail food rules administered with local public health agencies
- CDPHE Regulation 43 On-site Wastewater Treatment Systems: On-site wastewater systems in Colorado, including many rural restaurants, are regulated under Regulation 43 and county health departments
- CDPHE wastewater pretreatment program: Colorado implements the federal pretreatment program through CDPHE and approved local pretreatment programs, including Metro Water Recovery and Front Range utilities
- U.S. BLS Occupational Outlook Handbook, plumbers: BLS publishes the current median pay for plumbers, pipefitters, and steamfitters used to sanity-check labor lines