Fats, Oil, & Grease (FOG) - Sewers

Fats, oil and grease, also known as FOG, causes sewer blockages, leading to spills and overflows that are hazardous to our health. These spills can result in damage to our homes; pollute our local waterways and groundwater; and harm fish and wildlife habitats. The good news is, community members like us have the power to easily prevent damage from FOG, contributing to a better quality of life here in Delaware.

FOG in liquid form may not seem harmful, but don’t let that fool you. As FOG cools, it congeals and hardens, making it a toxic substance for the sewage system. It sticks to the inner lining of drainage pipes and restricts the wastewater flow, eventually causing a blockage. Using detergents or bleach may appear to help, but this is not the case. It is only a temporary solution. FOG will soon return to its thick, solid state—cleaners just send the FOG further down the sewage line. FOG build up is the number one cause of public and private sewage spills. Luckily, these situations are entirely preventable.

What is FOG?

FOG includes animal fats, vegetable fats, and oils used to cook and prepare food. FOG is a solid or viscous substance, which will ultimately create an obstruction in the sewer system if not properly disposed. Restaurants deal with larger volumes of FOG than homeowners and renters, but we all need to do our part. FOG can have a very negative impact if not handled properly. It can cause serious damage to the sewage system, your property and that of your neighbors, as well as damage to streets and waterways from sewage overflows. Cleanup can be very costly and this expense translates to higher bills for sewer customers. By being aware of what FOG can do to your surroundings it is easier to take that extra minute to prevent FOG from ending up in the sewer.

Where does FOG come from?

A byproduct of cooking, FOG comes from meat, fats, lard, oil, shortening, butter, margarine, food scraps, sauces, and dairy products. When washed down the drain, FOG sticks to the inside of sewer pipes. Over time FOG can build up, block entire pipes, and lead to serious problems. Directly pouring FOG down the drain after cooking is not the only way it gets into the sewer system; it drips off scraps that make their way into the sink and even items that are broken up by the garbage disposal can send FOG down the drain. Washing dishes (either in the sink or a dishwasher) can also cause FOG to get into the pipes if they aren’t wiped out before washing them.

What happens when FOG isn't properly disposed?

A wastewater sewer system works similarly to the circulatory system of the human body. Wastewater flows through pipes, is pumped at the pump stations, and is cleaned by the wastewater plant. FOG creates blockages within the sewer system that can lead to system failure as it builds up. FOG clings to the walls of the sewer system. FOG builds up one layer at a time making a smaller, narrower path for the water to travel through.

FOG in the sewer system can cause:

Raw sewage overflowing into homes—clean up is expensive and unpleasant, and often must be paid for by homeowners
Raw sewage overflowing into yards, streets and parks
Exposure to disease-causing organisms
An increase in operation and maintenance costs for local sewer departments, brining about higher sewer bills for New Castle County sewer customers

How should FOG be handled at home?

To dispose of FOG properly, follow these simple steps:

Never pour FOG into your sink or toilet
Pour FOG into a can- a coffee can works well
Place a lid over the top
Store it to be reused until full
When the can is full, throw it in the trash
When there is FOG residue in a pan or on a dish, wipe it with a paper towel before washing and throw that towel in the trash
Also, place a strainer in the kitchen sink drain to catch food scraps and other solids, then empty the strainer into the trash