Sanitary Sewer Overflows (SSOs)

Engineering Director

Thomas V. Clabo, P.E.
[email protected]
(865) 215-2148

400 Main St., Suite 475
Knoxville, TN 37902

Last item for navigation
  • Share on Facebook
  • Share on Twitter
  • Share via Email
Sanitary sewer overflows (SSOs) are a violation of NPDES permits that are issued by Tennessee Department of Environment and Conservation (TDEC).

What is an SSO?

A sanitary sewer overflow (SSO) is raw untreated sewage that discharges from the sanitary sewer system without first passing through a wastewater treatment plant. A typical SSO may occur at a manhole during wet weather, but can also occur in dry weather for a variety of reasons. An SSO is a public health hazard and a violation of federal, state and local discharge regulations.

Sign of SSOTypical signs of an SSO include:
  • Water flowing from manholes 
  • Toilet paper or other "flushables" 
  • Smell of sewage 
  • An unusually steady flow of water 
  • Residues, stains, or discolorations 
  • Displaced manhole lids 

Oftentimes, the SSO discharge may not look or smell unusual. The toilet paper may have been "filtered" within the sewer pipe or somewhere upstream. Or the discharge may be diluted by groundwater or surface water infiltration.

How you can learn more:

EPA - Raw Sewage Enforcement Alert [PDF]
Benefits of Protecting Your Community From SSOs [PDF]
Sanitary Sewer Overflows (EPA 832-K-96-001) [PDF]
EPA Web Site: Overview of Sanitary Sewer Overflows
EPA Web Site: Fact Sheets and Outreach Materials

Notice of SSO dischargeWhat you should do:

  • Avoid all contact with SSO discharges. 
  • Discourage children from playing in it. 
  • Report the SSO immediately to KUB switchboard at 865-524-2911. 
  • Report the SSO to local TDEC office at 865-594-6035 and to the City of Knoxville Water Quality Hotline at 865-215-4147 during business hours. 
  • Take notes and pictures to document the SSO problem for authorities. 
  • If you do not get satisfactory results with the steps above, please contact the US Environmental Protection Agency at: 404-562-9724.