Strategies to combat centralized sewer overflows

CSOs can significantly impair water quality and impact public health and wildlife. After non-point source pollution such as agricultural runoff and stormwater, CSOs are a leading source of water pollution in the US. Communities with extensive impervious surfaces such as parking lots, roofs, and sidewalks are particularly vulnerable. CSOs flood waterways and coastal watersheds with contaminants...

Capturing runoff where it falls in urban settings remains one of the primary goals in reducing CSOs, however given the urban setting this can be difficult as open land area can be in short supply and wet-weather water management can be difficult for communities faced with the challenge of discharging large volumes of minimally treated wastewater. Engineers and designers are discovering that the...

Separate the waste at the source. Separating storm and sanitary sewers is one solution; however it can prove very costly. A mid-sized US city with a population of less than 250,000 may have a wastewater utility district with over 805 kilometers (km) (500 miles) of sewer piping and approximately half of that may be combined sewers. The cost of upgrading and separating 402.5 km (250 miles) of...

While governments provide some funding for wastewater and stormwater infrastructure improvements, most funds are generated at the state and municipal level. Billions of dollars will be needed by local communities in the US alone just to meet federal regulations. As communities continue to grow and rain events become more intense, the need to enhance capacity of the wastewater and stormwater...

Dennis F. Hallahan, PE, is the technical director at Infiltrator Water Technologies, based in Old Saybrook, Connecticut, US. With more than 30 years of experience with onsite wastewater treatment systems’ design and construction, Hallahan has been responsible for technology transfer between Infiltrator and the regulatory and...