Fat Free Sewers
How to Prevent Fats, Oils, and Greases from Damaging Your
Home and the Environment
Fats, Oils, and Greases aren't just bad for your arteries and
your waistline; they're bad for sewers, too.
Sewer overflows and backups can cause health hazards, damage home
interiors, and threaten the environment. An increasingly common cause
of overflows is sewer pipes blocked by grease. Grease gets into the
sewer from household drains as well as from poorly maintained grease
traps in restaurants and other businesses.
Where does the grease come from?
Most of us know grease as the byproduct of cooking. Grease is found in
such things as:
- Meat fats
- Cooking oil
- Butter and margarine
- Food scraps
- Baking goods
- Dairy products
Too often, grease is washed into the plumbing system, usually through
the kitchen sink. Grease sticks to the insides of sewer pipes (both on
your property and in the streets). Over time, the grease can build up
and block the entire pipe.
Home garbage disposals do not keep grease out of the plumbing system.
These units only shred solid material into smaller pieces and do not
prevent grease from going down the drain. Commercial additives,
including detergents, that claim to dissolve grease may pass grease
down the line and cause problems in other areas.
The results can be:
Raw sewage overflowing in your home or your neighbor's home;
An expensive and unpleasant cleanup that often must be paid for
by you, the homeowner;
Raw sewage overflowing into parks, yards, and streets;
Potential contact with disease-causing organisms; and
An increase in operation and maintenance costs for local sewer
departments, which causes higher sewer bills for customers.
What we can do to help
The easiest way to solve the grease problem and help prevent overflows
of raw sewage is to keep this material out of the sewer system in the
There are several ways to do this.
Never pour grease down sink drains or into toilets.
Scrape grease and food scraps from trays, plates, pots, pans,
utensils, and grills and cooking surfaces into a can or the trash
for disposal (or recycling where available).
Do not put grease down garbage disposals. Put baskets/strainers
in sink drains to catch food scraps and other solids, and empty
the drain baskets/strainers into the trash for disposal.
Speak with your friends and neighbors about the problem of
grease in the sewer system and how to keep it out. Call your local
sewer system authority if you have any questions.
What Restaurant and Building Owners Need to Know About
Grease Traps or Interceptors
Restaurants, large buildings (such as apartment complexes), and other
commercial establishments may have grease traps or interceptors that
keep grease out of the sewer system. For a grease trap or interceptor
to work correctly, it must be properly
Designed (sized and manufactured to handle the amount that is
Installed (level, vented, etc.), and
Maintained (cleaned and serviced on a frequent basis).
Solids should never be put into grease traps or interceptors. Routine,
often daily, maintenance of grease traps and interceptors is needed to
ensure that they properly reduce or prevent blockages.
Be cautious of chemicals and additives (including soaps and
detergents) that claim to dissolve grease. Some of these additives
simply pass grease down pipes where it can clog the sewer lines in
This brochure was prepared under Cooperative Agreement Assistance
#CX824505-01-0 between the Water Environment Federation (WEF) and the
U.S. Environmental Protection Agency.