Fats, Oils, and Grease Control Program (FOG)


Fats, Oils, and Greases (FOG) enter the sanitary sewer through sinks, floor drains, dishwashers, and other kitchen equipment plumbed to the sanitary sewer. FOG and solid food waste entering your drains may cause blockages in either your plumbing or the sanitary sewer lines by building up along the walls of the pipes. This can lead to a sanitary sewer overflow inside your home, business, adjacent buildings, streets, or the environment. These spills are a safety hazard that can endanger public health and impact the health of our water resources.

FOG Control Program for Businesses

The City of Placentia is required by the Santa Ana Regional Water Quality Control Board (WDR Order 2008-0002) to implement a FOG Control Program. The program is intended to reduce and prevent sanitary sewer overflows (SSOs) caused by FOG blockages in the sewer lines. The City’s FOG Control Program includes the permitting of Food Service Establishments (FSEs). If you own an FSE in the City of Placentia, you may be required to obtain a FOG Wastewater Discharge Permit. 

All FSEs that are permitted will be inspected to ensure compliance with their FOG Permit and the City’s FOG ordinance.  Permitted FSEs must implement Best Management Practices (BMPs) to prevent or reduce the introduction of FOG to the sewer system and prevent SSOs.  Proper practices include the se of grease interceptors and traps that are designed to remove FOG from the wastewater stream.

Grease Traps and Interceptors

Grease traps and interceptors are two types of passive collection devices that protect sewer lines from blockages caused by excessive amounts of fats, oils, and greases. These devices route wastewater from kitchen drains through the interceptor or trap, slowing the flow to allow heavier solids to settle to the bottom while fats, oils, and greases float to the top. Grease will accumulate in the devices and allow relatively FOG-free water to flow from the device into the sanitary sewer system. To be effective, grease interceptors and traps must be installed according to the manufacturer’s specifications by a certified installation service. The Uniform Plumbing Code should be used to determine the proper size and capacity of the interceptor or trap.

Grease interceptors are configured with two or three chambers to catch FOG and other debris before they exit the sewer line. Interceptors are quite large, 500-2,000 gallons, and are usually buried outside the building they serve. A grease interceptor should have at least one manhole opening per chamber for inspection and cleaning and should be inspected at least once a month.

Grease traps are smaller than grease interceptors and are usually found inside the building they serve under a sink. Grease traps are usually single-chambered devices with baffles inside designed to slow the flow of wastewater. Their capacities are rated in gallons of flow and pounds of grease they hold. Being smaller, grease traps foul much easier when food grinders are used, or kitchen practices utilize sinks for waste disposal. Grease traps should be inspected weekly; skimming of collected grease at that time is highly recommended.

A full-service cleaning by a licensed grease interceptor/trap service provider is recommended at least twice per year to ensure that the interceptor/trap is completely cleaned and inspected. Your business is ultimately responsible for the proper use and maintenance of the interceptor/trap.

View more information on the City’s FOG Program.