In partnership with Seattle Public Utilities and Granite Construction, WaterTectonics conducted a three-month pilot project treating municipal stormwater runoff from a 234-acre industrial urban watershed. The project site was located in the South Park neighborhood in South Seattle and situated directly on the Duwamish River. Seattle Public Utilities assembled a Sampling & Analysis Quality Assurance Project Plan, provided automated sampling equipment, collected storm event samples, and helped with site logistical support. Granite Construction provided site grading and water storage tanks. WaterTectonics designed a five-step treatment process that included: grit chambers, electrocoagulation, clarification, media filtration, and carbon filtration. Multiple equipment configurations were trialed in order to determine the contributing effectiveness of each step of the process in overall pollutant reduction.