News Release 559

Department of Natural Resources investigates St. Louis-area wastewater overflows

Volume 38-559 (For Immediate Release)
Contact: Larry Archer

JEFFERSON CITY, MO, SEPT. 23, 2010 – A pair of wastewater overflows from a feature designed to help deal with stormwater resulted in the release of nearly 75,000 gallons of wastewater into a St. Louis-area creek Wednesday and today, according to the Missouri Department of Natural Resources.

Officials with the Metropolitan Sewer District contacted the department Wednesday to report an overflow of an estimated 52,000 gallons of wastewater from a constructed overflow, located behind 3620 Big Bend Blvd. in Maplewood, into Deer Creek.

The sewer district conducted a cleanup of the area, but when an inspector from the department’s St. Louis Regional Office arrived at the site this morning, a second overflow was in progress – this time releasing an estimated 22,500 gallons. District crews were able to stop the overflow and again clean the area.

Constructed overflows are features designed to minimize sewage backup into homes during heavy storms by directing the wastewater-stormwater mix into local streams once it becomes too much for the wastewater treatment system to handle.

The releases reported Wednesday and today were not caused by stormwater. Wednesday’s release was reported to have been caused by debris in the wastewater collection system. The cause of the second overflow is under investigation.

The department considers discharges of wastewater from sanitary sewer collection systems to be potential threats to public health and the environment. Such discharges have the potential to contaminate lakes and streams, causing serious water quality problems.

Sanitary sewer overflows can be caused by infiltration of rainwater and snow melt into aging systems, obstructions in sewer lines, mechanical failure, or undersized systems that cannot compensate for sudden increases in wastewater.

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 challenges in accomplishing this.

In order to protect public health and the environment, the department requires communities to take appropriate action to eliminate their sanitary sewer overflow issues. To do this, communities should develop a system to track information about such incidents, including the date, time, location and size of the overflow, 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 system upgrades.

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 webpage 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 website at