News Release 493

DNR investigates sewer overflow in Columbia

Volume 37-493 (For Immediate Release)
Contact: Renee Bungart

JEFFERSON CITY, MO., DEC. 21, 2009 -- The Missouri Department of Natural Resources is investigating a sewer overflow in Columbia that resulted in the release of more than 50,000 gallons of untreated wastewater into an unnamed tributary to Cedar Lake Friday.

The Boone County Regional Sewer District officials reported to DNR Friday that grease and rags blocked part of the sewer line causing untreated wastewater to overflow a manhole that serves the Rock Bridge Estates. The district discovered the overflow at 1:30 p.m. Friday. The district notified the department shortly before 5 p.m. about the overflow and reported it had stopped.

Investigators from the department’s Northeast Regional Office in Macon have been dispatched to the scene to collect water samples and investigate the incident.

The discharge of untreated or partially treated sewage from sanitary sewer collection systems, known as sanitary sewer overflows, or SSOs, are a significant threat to public health and the environment.

SSOs occur for several reasons. As sewer systems age they develop openings where excessive rainfall or snowmelt can enter and cause the water and sewage to exceed the sewer’s capacity. SSOs also occur when a community has an undersized sewer system, which means the sewers and pumps are too small to carry sewage from residential or commercial areas. SSOs also contaminate lakes and streams, causing serious water quality problems.

Communities across Missouri produce millions of gallons of wastewater that must be properly transported and treated before being released to waterways. However, some communities are facing SSO challenges in accomplishing this. In order to protect public health and the environment, the department requires communities to take appropriate action to eliminate their SSOs issues. To do this, communities should develop a system to track information about SSOs, including the date, time, location and size of SSOs, weather data, who notified them, when they notified the department and the measures taken to respond. The community can then use this data to aid in developing a plan to inspect the collection system and plan and finance upgrades the system to reduce SSOs.

For more information on sanitary sewer overflows or other water quality issues, contact the Department of Natural Resources’ Water Protection Program at 573-751-1300 or 800-361-4827 or visit the department website at

To report an environmental emergency, including sewage overflows, please contact the DNR spill line at 573-634-2436. For more information contact the department at 800-361-4827 or 573-751-3443, or visit the department's Web page at