Fats, Oils, & Grease (FOG) Program


Wastewater discharges containing high concentrations of fats, oils, and grease (FOG) from food service establishments (FSEs) have the potential to cause blockages within the City’s sewer system.

Blockages can result in:
  • Raw sewage overflows that may enter residential homes
  • Potential costs for damages or maintenance paid by the FSE found responsible
  • Potential contact with disease-causing organisms
  • An increase in operation and maintenance costs within the City Wastewater Division, which results in increased sewer bills for customers

This source of pollution is readily preventable by administering best management practices (BMPs) and the use of grease control devices (GCDs) at FSEs. To address this issue, the City has established a FOG Program.


Types of Fog

FOG refers to 
    Fats               Animal fat, either from trimmings, cooking, or off plates and flatware
    Oils               Generally cooking oil used in food preparation or off plates and flatware
    Grease         Byproducts from ingredients such as dairy, lard, etc.
Grease is commonly used as a general term for all restaurant byproducts.

Yellow grease
is an industry term for used cooking oil. It is collected from sources such as deep fryers or industrial sized griddles. It can be collected in tallow bins or recycling containers and sold for a profit.

Brown grease
is an industry term for the material recovered in GCDs. It is a combination of FOG, solids, and chemicals that are washed down into kitchen drains. GCDs collect brown grease to prevent it from entering the sewer system. It requires proper disposal from certified grease haulers.

Controlling FOG

New FSEs are required to have and maintain a GCD as well as administer kitchen BMPs to reduce the amount of FOG discharged into the sewer system.

Existing FSEs
that do not already have a GCD will not be required to install one unless it is found to be a significant source of FOG buildup. All existing FSEs will be required to administer kitchen BMPs.

Limited FSEs
that are only involved in reheating, hot holding, or assembly of ready-to-eat food products, whose wastewater discharge contains insignificant amounts of FOG, are not regulated by the City FOG Program.

City Environmental Compliance staff will visit restaurants and other FSEs at least annually to evaluate kitchen BMPs practiced and inspect GCDs. The inspector ensures that the equipment is functioning as designed and that it is cleaned and serviced at proper intervals.
  • The combined FOG buildup and solids must not exceed 25% of a GCD’s capacity at any time (25% Rule).
  • GCDs must be cleaned as frequently as needed to maintain efficiency, with servicing no greater than every three months unless a variance is issued by the City. FSEs must keep a record of their GCD maintenance including photo evidence and/or manifests from a rendering company.
Companies for GCD servicing and grease rendering can be found through the CDFA’s Rendering Enforcement Program.

For more information, contact Environmental Compliance staff at (925) 516-6076.

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