Fats, Oils and Grease (F.O.G)

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Grease GoblinWhat is F.O.G. ?

Fats, Oils and Grease or “F.O.G.” comes from cooking oil, shortening, lard, margarine, butter, dairy products and meat fat in food scraps.

Durham County has a F.O.G. Removal System Policy that regulates commercial establishments, such as restaurants, bakeries, grocery stores, schools, and institutions with on-site cafeterias. Residential customers are also significant contributors. But, there is no policy to regulate residential customers. Durham County has established a two hundred milligram per liter (200 mg/l) limit for the amount of oil and grease that can be put into the sewer system. The F.O.G. policy can be found in Durham County’s Sewer Use Ordinance (SUO) [PDF]

F.O.G. poured down kitchen drains accumulates inside sewer pipes. As it builds up, the flow through the pipe is restricted and can cause sanitary sewer overflows (SSO). The end result is sewage backing up into homes, yards, streets, storm drains and into creeks. These SSO’s can damage property, harm the environment and create health hazards.

Do’s and Don’ts

The following Do’s and Don’ts will help you avoid expensive sewer backups, plumbing emergencies, rate increases needed to cover maintenance and repairs and help to protect water quality.

  • Recycle used cooking oil or properly dispose of it by pouring it into a sealable container and placing the container in the trash.
  • Put food scraps in the trash and not the sewer system.
  • Use a “Dry Cleanup Method” by using a paper towel to scrape wet scraps from pots, pans and other cooking utensils into a can or trash for disposal.
  • Ever pour fats, oils or grease into sink drains.
  • Ever use a toilet as a wastebasket.
  • Ever use cloth towels or rags to scrape plates or clean greasy dishware. When the towels are washed the grease will end up in the sewer.


Guidelines for Requesting a
Grease Trap Cleaning Variance



  1. Before requesting a variance, the establishment must be in compliance with the Durham County Sewer Use Ordinance.  Section 26-102(c) pertains to “Fats, Oil, and Grease Removal Systems.”
  2. The establishment must request a variance in writing via letter or email sent to the Durham County Deputy Director of Engineering and Environmental Services – Utilities Division.

  3. Once the request for a variance has been received, the Pretreatment Project Coordinator must collect a sample from the grease trap effluent within 24 hours before a scheduled cleaning and have the sample analyzed for Total Oil and Grease.  Approved EPA and NC State guidelines shall be followed for sample collection, handling, and analysis. A NC certified laboratory shall perform the analysis.  The monitoring results shall be provided to the POTW for review.

  4. Less frequent cleaning may be permitted if it can be demonstrated that the proposed cleaning schedule will result in a discharge of fats, oil, and grease that is below 200 mg/L and there are no problems with sewer line maintenance as a result of the change in schedule.

  5. The Deputy Director/POTW Director will reply with a letter to the establishment either granting or denying the request for a variance.  If a variance is granted, a new cleaning schedule will be defined.

Variance Guidelines - PDF/Printable page