Constructed Wetlands for CSO Treatment: A Full-scale Pilot in Onondaga County, NY

As a signature project in the Onondaga County, NY “Save the Rain” combined sewer overflow (CSO) abatement program, the Harbor Brook CSO 018 Constructed Wetland Pilot Treatment System will treat combined sewer discharges up to the 1-year, 2 hour storm event that previously discharged to Harbor Brook without treatment. This full scale pilot program will test the effectiveness of three technologies — floating wetland island, vertical downflow wetland, and surface flow wetland — for reduction of bacteria, nutrients, total suspended solids, and 5-day biochemical oxygen demand. The goal of the pilot project is to confirm the technical, economic, and regulatory feasibility of using constructed wetlands for CSO abatement; confirm pollutant removal performance in a northeast climate; collect data to be used in optimizing the system; demonstrate wildlife and community benefits; and provide a basis for building local and nationwide acceptance of this green infrastructure concept.