Combined Sewer Overflows


Since the mid- 1800’s, cities have been constructed with sewer systems that carried both wastewater and storm water in the same pipe, which are referred to as combined sewer systems (CSS). CSS’s are sewers that are intended to collect storm water, domestic sewage, and industrial wastewater in the same pipe.

CSS’s are designed to convey their wastewater to a sewage treatment plant, where it is treated and then discharged into a water body. During periods of heavy rainfall or snowmelt, however, the wastewater volume in a CSS can exceed the capacity of the sewer system or treatment plant. Because of this, CSS’s are designed to overflow occasionally and discharge excess wastewater directly into nearby streams and rivers. The system was designed in this way to direct wastewater away from the city and to protect human health. These combined sewer overflows (CSO) can contain storm water, untreated human and industrial waste, toxic material, and debris. Without proper monitoring and management, CSO’s cans pose human health and environmental concerns to communities.


Currently, combined sewer systems serve about 772 communities and 40 million people. 
The Federal Environmental Protection Agency (EPA), West Virginia Department of Environmental Protection (WVDEP), along with the Huntington Sanitary Board (HSB) is taking steps to address pollution concerns created by CSO’s. The EPA has developed nine minimum controls which the HSB is currently implementing that help reduce the effects CSO’s have on water quality and human health. These measures include proper operation and regular maintenance programs for sewer systems and CSO outfalls, maximizing collection systems for storage, pollution prevention, public notification, and compliance monitoring of CSO overflows.

The city of Huntington has also implemented a Long Term Control Plan in accordance with the HSB’s WV National Pollutant Discharge Elimination System Water Pollution Control Permit, in order to manage and monitor its discharge’s from the 25 CSO’s within its system and better protect the citizens of Huntington, WV and to keep our water clean.

How Can I Help?

• keep paints, oils, pesticides and other harmful chemicals out of storm drains
• litter prevention, recycling, & proper disposal of yard waste
• detach roof downspout from combined sewer system (rain barrels, rain gardens, etc.)
• water conservation
• plant trees

Stay Safe!

• avoid contact with CSO river and stream locations during and for at least 48 hours after a rain event 
• as always wash hands and face after contact with any stream, river or lake.

Combined Sewer Overflow Locations