BARTON GSI FOR CSO CONTROL PROJECT | SEATTLE, WA
Owner/Client: King County Wastewater Treatment Division
SvR Role: Prime (Design)/Subconsultant (Study) - Planning, Civil Engineering & Landscape Architecture
Planning & Design Dates: 2011-Ongoing
Study Dates: 2007-2011
SvR is providing planning, civil engineering and landscape architecture services for the use of Green Stormwater Infrastructure (GSI) to control CSOS in Seattle’s Barton Basin. The proposed improvements are an alternative to controlling CSOs by the conventional concrete storage tank approach.
SvR worked with the King County Wastewater Treatment Division to design GSI facilities (specifically roadside bioretention/infiltration) for CSO control. SvR’s work included a feasibility review of retrofitting an existing residential neighborhood with GSI. The results of this work were presented to the community and the County’s key decision makers including the County Executive who selected GSI as the preferred alternative.
SvR has continued work on developing the improvements with King County, the City of Seattle and the Washington State Department of Ecology. The SvR team conducted geotechnical investigations, modeling calibration, and initial permitting activities to select the locations for GSI. Once technically feasible locations for GSI were identified, a conceptual design was developed and its performance reviewed using EPA SWMM modeling. SvR completed 30%, 60% and complete PS&Es for the entire project. Throughout the design SvR has partnered with King County in an extensive community relations program targeting area residents.