This project studies the creation of a wetland landscape on a barge that could be moored under Combined Sewage Overflows (CSOs) to treat effluent before it reaches New York Harbor.
This un-built project offers a solution to one of New York City’s greatest infrastructural problems: the discharge, during storm events, of untreated sewage and stormwater into New York Harbor from CSOs. More than 27 billion gallons of raw sewage and polluted stormwater discharge out of 460 CSOs into New York Harbor each year. As little as one-tenth of an inch of rain in an hour, or four-tenths of an inch of rain in a day, can cause CSOs to discharge. CSO events occur approximately once a week with an average weekly discharge of 500 million gallons of polluted water Citywide.
New York City is in the process of implementing long-term strategies to reduce the volume and frequency of CSO discharges, including providing rain barrels, encouraging green roofs, planting additional street trees and converting paved surfaces into plant beds. However, these changes will not likely have a measurable effect for decades. The CSO-to-go project seeks an interim strategy that is highly flexible and easily deployed, in order to immediately reduce the impact of CSO discharges on Harbor water quality.
The project team has developed a schematic design for a wetland landscape on a barge with 4 treatment zones targeted to remove the most common pollutants in NYC stormwater and sewage. The barge is designed to be moored at CSOs to treat effluent before it reaches the Harbor, and to provide educational and recreational interest at the waterfront. A fleet of such barges can efficaciously and cost-effectively improve Harbor water quality.