Sewage and Stormwater Overflows
Water Quality Information by Topic
Wastewater and sewage treatment are important topics in any society, all throughout history and into today. Improperly disposed of or treated sewage can cause disease and harm the ecosystem. That is why when a sewage overflow occurs it garners negative news attention.
• Water Science School HOME • Water Quality topics •
Urban Water Quality: Sewage Overflows
Credit: Alan Cressler, USGS
Many sewer lines are constructed next to streams to take advantage of the continuous, gradual slopes of stream valleys. Blockages, inadequate carrying capacity, leaking pipes, and power outages at pumping stations often lead to sewage overflows into nearby streams. There are three types of sewer systems:
- Storm sewers carry storm runoff from streets, parking lots, and roofs through pipes and ditches, and eventually into streams.
- Sanitary sewers carry raw sewage from homes and businesses to wastewater-treatment facilities.
- Combined sewers carry a combination of raw sewage and stormwater runoff.
This picture of a sanitary sewage overflow illustrates a common problem concerning sewage overflows that occur in urban areas. This overflow happened in Sept. 2009 during historic flooding in Atlanta, Georgia, USA. Sanitary sewer overflows occur when sewer pipes clog or pumping stations break down. As shown here, mixed sewage and rainfall runoff overflows from manholes and leaking pipes into nearby streams rather than backing up into homes and businesses.
Combined sewer overflows occur during storms when there is more stormwater flowing than the pipes leading to a treatment plant can handle. The excess runoff flushes human and industrial wastes, oil, toxic metals, pesticides, and litter into streams.
Want to learn more about urban water quality? Follow me to the Urban Land Use and Water Qaulity website!
Wastewater and sewage treatment are important topics in any society, all throughout history and into today. Improperly disposed of or treated sewage can cause disease and harm the ecosystem. That is why when a sewage overflow occurs it garners negative news attention.
• Water Science School HOME • Water Quality topics •
Urban Water Quality: Sewage Overflows
Credit: Alan Cressler, USGS
Many sewer lines are constructed next to streams to take advantage of the continuous, gradual slopes of stream valleys. Blockages, inadequate carrying capacity, leaking pipes, and power outages at pumping stations often lead to sewage overflows into nearby streams. There are three types of sewer systems:
- Storm sewers carry storm runoff from streets, parking lots, and roofs through pipes and ditches, and eventually into streams.
- Sanitary sewers carry raw sewage from homes and businesses to wastewater-treatment facilities.
- Combined sewers carry a combination of raw sewage and stormwater runoff.
This picture of a sanitary sewage overflow illustrates a common problem concerning sewage overflows that occur in urban areas. This overflow happened in Sept. 2009 during historic flooding in Atlanta, Georgia, USA. Sanitary sewer overflows occur when sewer pipes clog or pumping stations break down. As shown here, mixed sewage and rainfall runoff overflows from manholes and leaking pipes into nearby streams rather than backing up into homes and businesses.
Combined sewer overflows occur during storms when there is more stormwater flowing than the pipes leading to a treatment plant can handle. The excess runoff flushes human and industrial wastes, oil, toxic metals, pesticides, and litter into streams.
Want to learn more about urban water quality? Follow me to the Urban Land Use and Water Qaulity website!