By Jared Ebersole in Video 01 Aug 2026

Denny Farrell Riverbank State Park: The Park Above a Sewage Plant

Riverbank State Park sits on a 28-acre platform above the North River wastewater plant, supported by thousands of caissons driven into Hudson River bedrock.

Denny Farrell Riverbank State Park has swimming pools, playing fields, a running track, skating, a theater, lawns, and open views across the Hudson.

It also has four enormous exhaust stacks.

The stacks reveal what the landscaping is built on: one of New York City's largest wastewater treatment plants.

Where it is

679 Riverside Drive, New York, NY 10031

For much of its history, New York treated the Hudson River as part of its sewer system. Wastewater could be discharged with little or no treatment, carrying pathogens and pollution into the water surrounding the city.

Federal clean-water requirements forced cities to change. Manhattan's west side needed a major treatment facility, but there was no convenient 28-acre industrial parcel waiting beside the neighborhoods whose wastewater it would serve.

The city built into the river instead.

The North River Wastewater Resource Recovery Facility occupies a reinforced-concrete platform between roughly West 137th and West 145th streets. The plant began operating in 1986 and can treat hundreds of millions of gallons on a wet-weather day.

Supporting that facility required reaching through river sediment to reliable rock. The platform rests on approximately 2,300 concrete caissons pinned into bedrock as deep as 230 feet beneath the river.

The structure had to carry more than tanks and machinery.

West Harlem residents fiercely opposed placing a sewage plant beside their homes. The history was not abstract: communities of color had repeatedly received infrastructure that served the wider city while bearing its local pollution, traffic, noise, and odor.

The park was part of the response.

Inspired by projects in Japan that placed recreation over treatment facilities, New York built a public landscape on the plant's roof. Riverbank State Park opened in 1993, 69 feet above the river. Its 28 acres now receive nearly four million visits in a typical year.

This is not a thin green roof.

The deck supports soil, trees, pools, an athletic complex, skating rink, theater, restaurant, paths, and crowds. Buildings on the platform use lightweight construction where possible, limiting loads on the structure below. The park's geometry also has to coexist with ventilation, access, treatment equipment, and the operational needs of a facility that cannot simply close for a weekend.

The most visible compromise is the stacks.

Wastewater treatment produces air carrying hydrogen sulfide and other odor-causing compounds. Enclosing process areas captures that air, but it must then be treated and released. At North River, contaminated air is scrubbed with chemicals and passed through activated-carbon systems before fans discharge it through the tall rooftop stacks.

For years, the system did not solve the neighborhood's odor problem.

Residents continued reporting foul smells, and pressure for improvements persisted long after the park opened. In 2013, the Department of Environmental Protection completed a $106 million odor-control and monitoring project. Work included covering settling tanks, improving air capture, installing new ducts, scrubbers, adsorbers, and fans, and expanding real-time monitoring inside the plant, in the park, and in the surrounding community.

The need for those upgrades complicates the uplifting version of the park's story.

Riverbank is an extraordinary public space, but it did not erase the environmental burden underneath. The community had to keep fighting for the plant to operate as promised. A rooftop track is not a substitute for clean air.

At the same time, the combination is a powerful model for dense cities. Essential infrastructure consumes land, and hiding it at the urban fringe often transfers its harms to communities with less political power. North River instead places a working plant, a major public park, and the neighborhood's demands in the same visible structure.

Every visitor is moving across a piece of environmental machinery.

The pools and fields exist because engineers found a way to carry an entire landscape over the Hudson. The stacks exist because the machinery below still has to breathe.

The park hides a sewage plant, but never completely.

That may be the most honest part of its design.