Grease Interceptor Maintenance


Grease interceptor maintenance is required to keep fats, oils and grease (FOG) from entering the sewer system and causing overflows. A grease interceptor is an outdoor, in-ground device that removes FOG from wastewater before it enters the sewer.

Wastewater enters the interceptor from kitchen drains, and is slowed down so solids can settle to the bottom. Grease, being lighter than water, floats to the top. Interceptors are one of the most effective grease removal devices for food service establishments (FSE).

The required maintenance frequency for grease interceptors may be significantly reduced with the proper grease disposal practices. Refer to the Proper Disposal of Fats, Oils and Grease BMPs instruction sheet for more information.


Maintenance of interceptors includes removing all of the liquids and solids and disposing of the material in accordance with all federal, state, and local laws.  Cleaning policy of an interceptor is when the interceptor when 25 percent of the total volume is a combination of grease and solids. The best way to determine the appropriate pumping interval is to check the interceptor frequently after installation and estimate how long it takes the interceptor to fill up to 25 percent with grease and solids. Consulting with a reputable grease hauler can help to determine the appropriate maintenance schedule for your business.

Check the interceptor monthly, at a minimum, and pump out completely at least once every three months. Waiting too long to clean an interceptor can create an odor problem.


Removal of solids and liquids from a grease interceptor must be performed by a licensed grease hauler or recycler/renderer. Please refer to the Selecting Reputable Grease Haulers information sheet for more information on licensed grease haulers. If possible have an employee verify the grease waste hauler has completely pumped all liquids and solids out of the interceptor. Dry pumping is recommended; having the interceptor recharged, refilled by grease hauler, may contain unwanted waste.


The grease hauler should record the volume of grease and liquid removed and provide a receipt. Keep receipts from a West Virginia licensed grease waste haulers for two years to demonstrate proper interceptor maintenance.


Stop water flowing to the interceptor and notify the Beckley Sanitary Board of the spill by calling 304-256-1760 as soon as possible. You probably will need to call a plumber to clean sewer lines and verify the interceptor is working properly. If cleaning sewer lines, clean from the interceptor outlet to the main sewer line in addition to cleaning the lines from the building to the interceptor inlet. This will help avoid future overflows. Prevent outdoor grease over flows from impacting public health and the environment, including storm drains by containing the overflow using dirt if necessary, or another substance, until all grease is cleaned up. Clean any FOG that is on the ground by using absorbent materials, then placing the materials in plastic bags and place in the trash. Never use water to clean FOG spills.

Got Questions? Contact Beckley Sanitary Board Today.