Revealing Wastewater Ecologies: A Combined Sewer Overflow Strategy and Treatment Facility Design for Seattle's Georgetown Neighborhood

Abstract

The 21st century infrastructure used to convey and treat sanitary waste and stormwater runoff is largely screened, hidden or buried from public view. In much of Seattle, as in many older cities, stormwater is conveyed in the same pipe as sewage to distant wastewater treatment plants, leading to frequent combined sewer overflows of contaminated water into rivers, streams and the Puget Sound during storm events. This thesis proposes a new strategy for addressing combined sewer overflows occurring on one stretch of the Duwamish River. Specifically, this thesis will investigate how the design of a combined sewer overflow treatment facility and site, conveyance route and discharge in Seattle's Georgetown neighborhood can become a community amenity, increase ecological function and raise awareness of urban runoff and water quality issues in the built environment and the high costs of conveying water to distant and energy-intensive treatment plants.