Publicly owned treatment works

Stickney Water Reclamation Plant

Publicly Owned Treatment Works (POTW)

Publicly Owned Treatment Works (POTW) are wastewater treatment facilities that are owned and operated by a government entity, typically a municipality or public utility. These facilities are responsible for treating domestic sewage and industrial wastewater to ensure that it meets the standards set by the Clean Water Act before being discharged into the environment.

History

The development of POTWs in the United States began in earnest with the passage of the Clean Water Act in 1972. This legislation provided federal funding for the construction and upgrading of wastewater treatment plants, significantly improving the quality of water bodies across the country.

Function

POTWs are designed to remove pollutants from wastewater through a series of physical, chemical, and biological processes. The primary stages of treatment include:

• Primary Treatment: This involves the removal of large solids and debris through screening and sedimentation.
• Secondary Treatment: This stage uses biological processes to degrade organic matter in the wastewater. Common methods include activated sludge and trickling filters.
• Tertiary Treatment: This advanced treatment stage further removes nutrients and contaminants through processes such as filtration, disinfection, and chemical precipitation.

Regulation

POTWs are regulated under the National Pollutant Discharge Elimination System (NPDES) permit program, which is administered by the Environmental Protection Agency (EPA) and state environmental agencies. These permits set limits on the types and amounts of pollutants that can be discharged from the treatment works.

Challenges

POTWs face several challenges, including:

• Aging Infrastructure: Many POTWs were built decades ago and require significant investment to maintain and upgrade.
• Emerging Contaminants: New pollutants, such as pharmaceuticals and personal care products, are increasingly being detected in wastewater and pose treatment challenges.
• Climate Change: Increased frequency and intensity of storms can overwhelm POTW systems, leading to combined sewer overflows (CSOs) and other issues.

See Also

• Wastewater treatment
• Clean Water Act
• National Pollutant Discharge Elimination System
• Environmental Protection Agency
• Combined sewer overflow