Why do overflows exist?
Many years ago, prior to the existence of an environmental protection agency or Clean Water Act,  it was considered best engineering practice to design such relief points in a sewer system in order to prevent backups into homes during wet weather.

Where are the overflow points located?
Discharge locations that may activate are along the Olentangy River from Worthington to First Avenue, on the Scioto River from around Neil Avenue to S.R. 104, and on Alum from Main Street to I-70.   The locations are marked with signage.  View a map link here. 

Are overflows an issue in other U.S. cities?
Yes.  Solving wet-weather issues is the biggest challenge facing most sewer districts today. 

What is the City of Columbus doing about overflows?
The Division of Sewerage and Drainage (DOSD) entered into agreements with the State of Ohio in 2002 for SSOs and in 2004 for CSOs. To meet these orders, A Wet Weather Management Plan was submitted to the Ohio EPA in July, 2005. The plan is expected to generate $2.5 billion in capital improvement projects over the next 40 years. Please see the Project Clean Rivers page for more information. 

How will the elimination of overflows affect sewer rates?
In order to pay for the improvements, sewer rate increases will be necessary.  An affordability analysis was conducted to ascertain the community's ability to pay for the projects. Rate increase needs will be reviewed on a yearly basis. 

How are sewer improvements financed?
Unless federal funding becomes available, sewer improvements will be financed through customer sewer rate revenue and by low-interest loan programs such as the Water Pollution Control Loan Fund through the Ohio EPA.

How will central Ohio residents benefit?
Anything that improves our environment and water quality benefits the entire community.  Solving wet weather sewer issues will also reduce sewer backups into basements.

How many overflow points are in Columbus?
There are 41 SSO and 20 CSO discharge points owned by Columbus that can potentially overflow. There are multiple engineered relief points within the sewer system that share common discharge points.  An additional 10 SSO discharge locations are owned by other municipalities, two of which are maintained by Columbus under contract.

How often do they overflow?
The most active one is the Whittier Street CSO on the Scioto, which receives partial treatment. The frequency and volume depend on the amount of rainfall and other factors. View discharge information here or view the previous year's annual report submitted to the Ohio EPA.

If I see an overflow warning sign, is it safe to swim near it?
No. First, be aware that swimming in local waters is prohibited by Columbus City Code and is considered a dangerous drowning risk in some locations due to low-head dams and utility crossings. To avoid possible negative health effects, always avoid water contact near a sewer overflow location, especially following periods of heavy rain. For more information, please click here for reports from the U.S. EPA on the health and human impacts of CSOs and SSOs. 

Can residents help prevent overflows?
Yes.  Check your downspouts and foundation drains to make sure they are not connected to the sanitary sewer. These outdated connections, which were common in homes built prior to 1963, add excess water to the system during wet weather. For an instructional disconnection brochure, please call (614) 645-2123.

Disposing of grease properly is also important as grease can block city and homeowner pipes, causing overflows and backups. Do not pour grease into sinks and drains. Place grease in the trash after it cools in a sealed container such as a coffee can. Also, please attend to any known repair needs on your home sewer line to prevent excess water from entering the system through cracks and tree roots.

Should residents report a suspected sewer overflow or basement backup?
Yes.  Please report any suspected overflow or basement backups in Columbus immediately to the city's 24-hour Sewer Maintenance Operations Center at (614) 645-7102.  This is also the first step to determine eligibility for the Project Dry Basement backflow prevention program to prevent sewer backups into single and two-family homes.

For questions, please email us or call (614) 645-7175.