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Food Service Industry and FOG (Fats, Oils and Grease)

The Grease Problem

Manhole outside local restaurant  filled with grease.When businesses disregard sewer regulations and improperly dispose of fat, oil and grease to drain, sewer lines can become clogged causing sewage to backup into basements of homes and businesses. This picture was a sewer manhole outside of a Longmont restaurant. In response to this violation and other sanitary sewer overflows due to grease, the City began a FOG Control Program in 1998 which included educational outreach to local food establishments.

To work effectively, sewer systems need to be properly maintained from the drain to the treatment plant. Grease is an example of a waste that the sewer system cannot handle, and therefore should not be put down drains. The City needs businesses and individuals to do their part in maintaining the system. Repeated repairs and maintenance deplete City resources, and are disruptive to residences and businesses. Furthermore, the Longmont Municipal Code requires proper disposal of grease by commercial establishments.

Since 1998, we have expanded our education program to include institutions, wholesale bakeries, nursing homes and residents. For businesses in violation of the Code, enforcement actions (warning letters, notice of violations, administrative orders, civil penalties and criminal enforcement actions) have been employed to swiftly bring the businesses back into compliance. And, we have seen a marked decrease in the number of sanitary sewer overflows related to grease.

In 2009, the Industrial Pretreatment Program again made improvements to the program by increasing the number of regulatory inspections of all food establishments.


GI Installation

GI Maintenance

Recycling Cooking Oil

Storm Water BMPs


Informational Brochure

Installation (486 KB)

Trap vs Interceptor (68 KB)

Sizing Example (97 KB)

Maintaining Interceptors

Maintaining Traps (243 KB)

Spanish (108 KB)

Trap Maintenance Logs (39 KB)

Spanish (39 KB)


IP Program


501 East 1st Avenue

Longmont, CO 80501

Phone (303) 651-8667

or email

BUSINESSES LISTED IN BROCHURES AS THOSE SERVICING THE LONGMONT AREA- Business listed in the above brochures are provided for your convenience. Inclusion or omission of any business listed in brochures in no way implies endorsement or rejection by the City of Longmont or the Industrial Pretreatment Program. Any business servicing Longmont interceptors (or fryer oil recycling) may call 303-651-8667 to be included in future printings.

Can't view pdf files? More information is available for installing Acrobat Reader.
Or call (303) 651-8667 for hardcopies.


Grease Interceptor - Installation

The City's Municipal Ordinance (Section 14.08.415) requires all commercial establishments engaged in the preparation and sale of food, have commercial garbage grinders or produce amounts of grease that have the potential to cause partial or full blockage of the sewer to install and maintain an adequately sized grease interceptor. Examples of businesses in this category are (but not limited to): restaurants, fast food restaurants, cafes, lunch counters, bars, coffee shops, kitchens in hotels, bakeries, dairies, ice cream shops, slaughterhouses, grocery stores with delis and any business that has a cafeteria (hospitals, country clubs, industries, etc.).

Failure to install an interceptor is a noncompliance of the City Ordinance and therefore, unlawful.

Contact the City's Building Inspection Department to obtain permits at (303) 651-8322. Chapter 16 of the Municipal Code requires that sizing, installation and design conform to the currently adopted plumbing code. This requires that the manufacturer's criteria be used. The City does not provide design or sizing consultation. It is the owners responsibility to ensure that the interceptor is adequately sized and correctly installed.

It is recommended that the Boulder County Health Department is contacted for information on other requirements such as the requirement for air gaps between the trap and the fixture.

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Grease Interceptor - Maintenance

The Municipal Code (Section 14.08.416) requires that the interceptor be inspected and maintained regularly. Another requirement is that the maintenance must be documented.

All establishments with grease interceptors should use Best Management Practices to reduce the amount of grease entering the sewer. Failure to inspect and maintain your interceptor is a violation of the Code. The City suggests maintenance be performed when the interceptor is about 60% full of grease and solids. Cleaning out more often will not increase the efficiency of the interceptor, but will result in higher costs. Cleaning out less often will reduce the efficiency of the interceptor and may produce odor problems or a corrosive environment that will shorten the life of the interceptor.

All maintenance is at owners expense and must be documented. Documentation for interceptors is the haulers manifests. For traps, keep a written log to show when maintenance is performed. During City inspections, your documentation will be reviewed. Lack of documentation is a violation of the Code.

Chemical/Biological Treatment

The use of these products does not absolve dischargers from installation, inspection/cleaning or documentation required by the Code. Frequently, the IP Program is approached by sellers of these products. The City does not give written permission to sell any product to Longmont businesses. The City does not promote the use of these products. The City does not give advice on how to best sell any product to Longmont customers. The City does not provide lists of customers to sellers.

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Pollution Prevention|Industrial Pretreatment Program|Wastewater Treatment |Public Works & Natural Resources|City of Longmont

This page was updated August 16, 2013
City of Longmont Public Works & Natural Resources
Industrial Pretreatment Program