Combine Sewer Overflows (CSO's)
Managing Risk to Water Quality
Since the mid-1800s,cities have been constructed with sewer systems that carried both waste water and storm water in the same pipe. Original designs were configured to carry all the wastes and runoff to local streams, lakes, and rivers. By the 1950s, citizens and municipal authorities recognized the need to separate these flows and began constructing waste water treatment plants. As sewers were replaced, or when new ones were constructed, storm water collection was confined to its own drainage system, and wastes were sent to the treatment plant.
Without proper monitoring and management, combined sewer overflows (CSOs) from existing sewer systems pose a significant threat to communities where they are in place. Currently 40 million people in 900 communities nationwide (about 390,000 people in 56 counties in WV ) live in areas with CSOs. CSOs contain untreated domestic waste and may contain commercial and industrial wastes, surface runoff containing contaminant from various sources, and particulate pollution in the air.
Outbreaks of communicable diseases such as typhoid, cholera, dysentery and hepatitis
have been traced to contaminated drinking water. Swimming and other water-contact
recreation in areas affected by CSOs also can put you at risk, especially if you
have cuts or scrapes where bacteria can enter the body.
The EPA and WVDEP are taking steps to address hazards created by CSOs. In August 1989, the EPA issued a national strategy for better managing CSOs. This strategy requires states to identify all CSOs and categorize them according to their level of compliance with the Clean Water Act requirements.
The EPA has developed nine control measures to help reduce the effects CSOs have on water quality. These measures include proper operation and regular maintenance programs for sewer systems and CSO outfalls, maximizing collection systems for storage and minimizing the flow of storm water into the CSO.
Below is a map of Moundsville, WV with CSOs marked in read. You can click an overflow
to link to a more site specific page.