What is FOG?
Fats, Oil and Grease! FOG comes from food such as cooking oil, lard, shortening, meat fats, sauces, gravy, mayonnaise, butter, ice cream and soups. Sink, dishwasher, hood and floor cleaning wastewaters and food scraps may also be sources of FOG. FOG can either be liquid or solid and may turn viscous or solid as it cools in the underground sewer. For additional information, select the Notice to Food Service Establishments and Best Management Practices link located below.
FOG can pollute the environment!
When not disposed of properly, FOG can cause blockages in the sanitary sewer which can result in sewer backups inside a restaurant or spew wastewater from sewer manholes onto private property and the streets. These sanitary sewer overflows can then pollute our streams, the Potomac River and the Chesapeake Bay.
FOG can cause costly repairs!
FOG can create acidic conditions that can corrode or dissolve concrete or iron sewer pipes. Wastewater overflowing out of sewers can potentially “wash out” roads, contaminate groundwater and pollute our environment. Dischargers of FOG may be held liable for cleanup and repair costs related to sanitary sewer damage, backups and overflows.
How can you control FOG damage?
Learn to control the disposal of FOG during food preparation, cleanup and kitchen maintenance. Wipe off dishes, pots, pans and cooking utensils before rinsing or washing. Collect waste cooking oils in grease barrels and schedule the pickup of the barrels before they are full. Install a grease trap (typically inside) or grease interceptor (typically outside) to trap the FOG before it enters the county sewer lines. Check the depth of grease and food solids in the trap/interceptor regularly. Grease traps may be cleaned by restaurant staff or a licensed sewage handler. Interceptors must be cleaned by a licensed sewage handler. Schedule a clean out by a licensed sewage handler before the combined depth layer of the floating FOG and settled solids total more than 25 percent of the operating depth of the grease unit on the outlet side of the tank. The operating depth is the depth from the water level at the outlet pipe to the bottom of the tank.
Track the performance of your grease trap/grease interceptor!
Keep a record of the cleanout dates, the depths of the floating FOG layer and settled solids in the grease tank, approximate volume removed, and the name of the employee/licensed sewage handler who cleaned the grease tank. Post the maintenance log near the sink or maintain it in a file. Fairfax County inspectors will periodically check the record during inspections.
If you have any questions, please call the Department of Public Works and Environmental Services' Industrial Waste Section at 703-550-9740, extension 252, TTY 711.