FOG is short for fats, oils and grease. FOG is found in lots of foods such as meats, sauces, salad dressings, foods cooked in deep fat fryers, cookies, pastries, cheese, butter and many, many more. FOG is in many places in all kitchens and food services.

In the sewage collection and treatment business, the answer is YES! Grease is singled out for special attention because of its poor solubility in water and its tendency to separate from the water and adhere to other surfaces.

Fats, oils and grease in the sanitary sewer coats the insides of the pipe, causing maintenance problems. The consequences include reduced sewer capacity and pipe blockages leading to sanitary sewer overflows.

Oil and grease also hamper effective treatment at the wastewater treatment plant. Grease in a warm liquid may not appear harmful. But, as the liquid cools, the grease or fat congeals and causes mats to form on the surface of settling tanks, digesters, and the interior of pipes and other surfaces which may cause a shutdown of wastewater treatment processes.

Problems caused by wastes from restaurants and other grease-producing establishments have served as the basis for this ordinance and other regulations on the discharge of grease materials to the sanitary sewer system. Typically a grease trap or grease interceptor is required to control FOG discharges.

King County Metro requirements for sewer state that FOG discharges are limited to 100 mg/L. This equals one teaspoon per thirteen gallons, a very small amount!

If you discharge FOG to the sewer system then it is likely that you will be required to install either a grease trap or a grease interceptor.

BMP stands for Best Management Practice. BMPs are useful for reducing the amount of FOG that goes down the drain, thereby reducing cleaning frequencies on grease traps and interceptors. Reduced FOG also lowers the risk of clogged pipes and sanitary sewer overflows. An example of a BMP is wiping excess grease out of pots and pans with a paper towel before washing them.