Puget Sound Beach CSO Control Projects

King County begins selection process for Beach CSO Control Project alternatives fall 2009

Click on map location for project details.

Combined Sewer Overflows (CSOs) occur in older parts of King County’s wastewater system that carry both wastewater and stormwater to the treatment plant. When heavy rains fill the pipes, excess stormwater and sewage flow directly into local waterbodies. The combined sewer overflows are about 90 percent stormwater and the rest is diluted sewage. Historically, CSOs were designed into the system to avoid damage to facilities and sewer backups into homes and businesses and onto streets during storms.

Today, CSOs are a concern because untreated wastewater and storm water may be discharged to Puget Sound during large storms posing risks to public health and the environment. To meet state regulations, King County's goal is to reduce the number of CSOs each year, with a long-term goal of less than one untreated discharge per location per year.

As part of its CSO Control Program, King County is identifying CSO control approaches for Barton, Murray, North Beach, and South Magnolia. These locations are top priority because people are most likely to come in contact with water during recreational activities such as swimming.

Basin-specific approaches to CSO control

The CSO Program assembles a “toolkit” of potential approaches for CSO control. CSO Project teams work to identify approaches in that toolkit that address the problem defined in each project area. The approaches will be developed into alternatives specific to each basin.

You can participate during alternatives selection

Beginning in fall 2009, the project team will begin evaluating a broad range of alternatives using a range of criteria. Preferred alternatives will be brought forward for further evaluation. King County will select a final alternative for each basin in 2010.

Public comment will inform the alternatives selection process. Visit the Alternatives Selection page to find out where King County's decision process is at, and how you can participate.

King County is committed to working with you

King County will work with the public throughout the life of these projects, providing information and opportunities to express comments, questions, and concerns:

• Work with each basin's community and interested citizens during the alternatives selection process
• Identify potential community and environmental impacts in the environmental and design review processes.
• Continue an information and involvement program throughout design, construction and of the facilities
• Provide 24/7 contact information for questions and concerns during operation