Fats, oils and greases (FOGs) are expected by-products of food preparation, whether on a large scale as found in the food industry, or the incidental amounts caused by residential cooking. When cooking fats, oils and grease are poured down the drain, they tend to collect and stick to household plumbing and sewer lines. Over time blockages occur that lead to sewer backups, sometimes causing sewage to overflow from plumbing fixtures or sewer system manholes.
Tumwater Municipal Code, Section 13.08.065 prohibits “any wastewater having a fat waste, oil or grease (FOG) content, whether or not emulsified, in excess of one hundred (100) milligrams per liter” from being discharged through the city sewer system to the LOTT wastewater treatment facility. Greases and other food wastes can quickly accumulate and cause blockages in smaller pipes heavily used by food services.
Contributing to the blockage problem is the widespread use of products designed to emulsify wastes or otherwise clear drains of grease build-up. These products include biological and chemical treatment agents, and cleaners such as caustic and lye. While these products may clean or open your drains, they do not render the grease harmless; instead, once the grease moves downstream it tends to coagulate again. If this happens often enough, businesses or homes may experience expensive and inconvenient sewer back-ups. While emulsifiers and cleaners may clear pipes in the short term, they create larger and more expensive problems for you and your sewer utility in the long term.
To avoid future blockage problems, the City of Tumwater has developed the FOG Program to educate food service providers on the proper practices for dealing with FOG. Proper practices include the use of grease interceptors and traps that are designed to remove FOG from the wastewater stream.