Sewage Spills and Backups

Sewage spills (sanitary sewer overflows) are caused by the clogged of pipes and/or too much flow. Clogged pipes are caused by blockages from fats, oils and grease as well as rubbish, roots and other foreign or unwanted objects in the sewer system. Too much flow is caused by infiltration and inflow i.e., groundwater and rainwater getting into the sewer system). The following sections discuss each cause in detail.

Keeping fats, oils and grease out of the sewer system

Fats, oils, and grease, and other byproducts of cooking come from meat, lard, shortening, butter, margarine, food scraps, sauces, and dairy products. They present a significant clogging problem for sewer systems. Fats, oils and grease stick to the inner walls of sewer pipes and reduce the diameter of the pipes over time. This eventually causes clogged sewer pipes and sewage spills.

Clogging is further caused by chunks of grease breaking away from the pipe walls and becoming stuck further down the line. Grease balls that form when grease combines with sand, grit, and other sewage debris can even become large and hard enough to clog sewage pumps!

Fats, oils and grease also flow down to the wastewater treatment plant where it disrupts operations and increases maintenance costs.

Regulations require restaurants and other commercial food handling facilities to install large grease separation devices to protect sewers from grease problems. 

How should we properly dispose of grease and oils?

Everyone can do their share to prevent clogged sewers by following these simple do’s and don’ts

DO's:

DON'Ts:

Some other points to remember:

Keeping rubbish out of the sewer system

Your toilet and sewer system are only designed to dispose of human wastes and toilet paper (which quickly breaks down). Unfortunately, people use the toilet as a wastebasket out of convenience. It is a huge "out of sight, out of mind" problem because people often don't see the mess sewer overflows cause and the problems that sewer workers need to deal with.

Almost any type of rubbish may restrict sewage flow, clog sewers, and cause sewage overflows. Keep the following from going down your toilet and sinks:

Why is it a problem?

Rubbish and other objects often combine with hair, grease and other debris to cause clogging of the sewer system. Even something as small as a cotton tip swab with other attached debris can cause a blockage in sewer pipes. Rags and stringy material can clog sewage pumps. Malfunctioning sewage pumps, like clogged pipes, prevent sewage from flowing through the system and are a cause of spills. Any rubbish-type items that you dump in toilets and sinks at home, work, schools, shopping centers, movie theaters, or parks can contribute to sewage spills.

Do your share to keep rubbish from clogging our sewers by following these simple Do's and Don'ts.

DO's:

DON'Ts:

 If liquid is coming out of a manhole cover with "Sanitary Sewer" on it, it is probably sewage. Note that sewage is not brown or yellowish in color but actually looks like dirty gray dishwater. Especially during heavy rain, take note of and report any sewer manhole covers that you see lifting up and spilling sewage.

Quick action is required to reduce the risk of public exposure to raw sewage by stopping the overflow, monitoring its impact, and ensuring proper cleanup.