Barton CSO Control ProjectGreen stormwater infrastructure 
April 30, 2012 Update
King County hosted two community meetings on March 28 and 31. The meetings included a short presentation on bioswale design and street selection followed by sessions to discuss selected streets in detail and receive neighborhood feedback. Now posted: meeting minutes and breakout session notes.
Note: breakout session notes allow residents to see what other small groups discussed. Answers to comments and questions can be found in meeting minutes or FAQs. For additional comments or questions, please contact Kristine Cramer: 206-263-3184 or Kristine.cramer@kingcounty.gov
To view preliminary design locations, look at the breakout area sessions map and then click on the detailed area maps (Area 1, Area 2, Area 3 and Area 4).
Field work investigations, findings and implications for design
Between February 2011 and January 2012, the Barton CSO Control Project team completed field investigations to better understand the above and below ground characteristics of the project area. The results of this field work have informed project design. Learn more. 
Barton basin and project location.
Barton CSO Control Project GSI area and Barton basin (PDF)
Project descriptionKing County is designing bioretention swales, a type of green stormwater infrastructure, in the City of Seattle’s parking strips in the Sunrise Heights and Westwood neighborhoods. Street runoff will be diverted away from storm drains and into the vegetated swales. Once in the swales, the water will filter through soil to an underdrain, which will take the water deep underground and allow it to slowly infiltrate into the soils. This bioretention swale system is needed to reduce the amount of stormwater entering the combined sewer system which can cause combined sewer overflows (CSOs) of sewage mixed with stormwater at the Barton Pump Station near the Fauntleroy ferry dock. Why does King County need to do this project?The county must meet current regulations set by the Washington Department of Ecology that require no more than one untreated discharge per year on average. Taking stormwater out of the conveyance system in Sunrise Heights and Westwood will reduce CSOs at the Barton Pump Station. Like many older cities, Seattle built one system of pipes to carry both wastewater and stormwater to treatment plants. To prevent sewer backups into homes and streets, the conveyance system includes overflow locations that release excess flows directly to Seattle water bodies during storms. CSOs contain more harmful chemicals and disease-causing pathogens than stormwater alone. King County currently averages four overflows per year at the Barton Pump Station, releasing approximately four million gallons of dilute sewage and stormwater into Puget Sound. Why is this project happening in Sunrise Heights and Westwood?There are two primary reasons for siting the bioretention swales in this area. - Most of the neighborhood (150 acres) is connected to the combined sewer system. That means that when you run water in your house, the wastewater flows into pipes that also capture stormwater.
- 45% of all the combined sewer and stormwater flows to the Barton Pump Station comes from Sunrise Heights and Westwood.
Capturing the stormwater before it enters the sewer pipes and sending it deep underground reduces flows in the pipes during large storms and prevents overflows, which helps King County meet its regulatory requirements and reduces pollution into Puget Sound. Project schedule
King County is committed to working closely with project area neighbors. Please contact us at any time for more information, to ask questions, voice concerns, or request a block meeting. Please contact Kristine Cramer, Kristine.cramer@kingcounty.gov or 206-263-3184.
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