Grease Trap Maintenance

Grease traps require frequent maintenance in order to remove fats, oils and grease (FOG) from wastewater before it enters the sewer. Grease traps are generally under the sink, but can be found in the floor.

There are two types of grease traps: manual and automatic. You should know where your grease trap is located and how to open and maintain it.

Grease traps are only permitted when physical limitations will not allow a grease intercepter to be installed with in 30 feet of the fixtures served.


Follow the Proper Disposal of FOG Best Management Practices (BMPs) so that traps do not have to be cleaned as often. Refer to the Proper Disposal of Fats, Oils and Grease BMPs instruction sheet for more information.


Automatic indoor grease traps do not clean themselves. Automatic indoor grease traps should be easily accessible and cleaned daily by removing grease and cleaning out the screening baskets. Manual grease traps need to be cleaned at least weekly, but if the trap is more than 25 percent full of grease after one week, the trap should be cleaned more often. Never use hot water, acids, caustics, solvents or emulsifying agents when cleaning grease traps. Dishwashers should not be plumbed to grease traps, because of the higher temperature of dishwater and detergents that keep grease from separating from the water.

Automatic Indoor Grease Trap - Once Per Day
Manual Indoor Grease Trap - Once Per Week


Grease from automatic grease traps can be mixed with used oil and grease that is placed in a recycling bin (i.e. tallow bins). After removing grease from a manual grease trap, solidify by mixing with an absorbent material, such as kitty litter, and bagging before disposing in the trash.


Food service employees or cleaning services may maintain indoor grease traps. Grease trap maintenance records should be kept for three years to demonstrate proper maintenance of the grease trap. Maintenance records should include who cleaned the trap, on what date, and the approximate amount of substance removed.


Stop the water flowing to the grease trap, let management know immediately and take immediate action to contain the overflow. The local sewer agency may need to be notified and a plumber called to clean sewer lines and check if the trap is working properly.

Got Questions? Contact Beckley Sanitary Board Today.