Yesterday, OHNY’s staff got to tour the Motor Vessel Red Hook, one of three sludge boats in D.E.P.’s fleet. The tour started at the North River Plant (one of New York City’s 14 wastewater treatment plants) with Steve Askew, the Plant Superintendent.

Located on the Hudson River, west of the West Side Highway from 137th Street to 145th Street, the plant provides wastewater treatment for a third of Manhattan’s waste (from residents from Bank Street in Greenwich Village to Inwood Hill). North River, which Steve described as a ‘mega’ plant, treats about 125 million gallons of wastewater every day during dry weather and can handle up to 340 million gallons a day when the weather is wet! 150 people work at this facility and it is basically a 24 hour operation.

North River Plant lobby

Built on a 28-acre reinforced concrete platform over the Hudson River, the roof is home to Riverbank State Park, making it the only wastewater treatment in NYC to have a public park built on top. Planning for the plant began in 1962 but it did not open for advanced preliminary treatment until 1986. (Before then, untreated wastewater flowed into the Hudson River.)

Designed by Phillip Johnson, North River has been widely recognized for its innovative design. Johnson’s utilized plain geometric shapes in order to create ‘a modernist sculpture.’ The design was modified during the following two decades while the foundation, made up of hundreds of caissons put directly into the bedrock, was built. The resulting concrete facade of arches spans ten blocks and faces the river.

Boarding the M.V. Red Hook

After learning about the North River Plant, we boarded the Red Hook, a 1.2-million-gallon sludge vessel that took three years to build and is the newest and largest vessel in D.E.P.’s fleet. Captain Chris Reil led us through the boat, which is more than 350 feet long, about 53 feet wide and weighs more than 2,098 tons. The Red Hook is ~1 1/2 years old and the lifespan of the sludge boats is typically 30-40 years. Named after wastewater treatment plants, the Red Hook is joined by the Newtown Creek and the North River. In 2007, the Owls Head was retired after more than 50 years in service and sold in West Africa.

Captain Chris Reil shows us around

The Red Hook’s eight storage tanks can accommodate 150,000 cubic feet, or 1.2 million gallons, of sludge. Sludge is most of the residual material removed during the treatment process. (Another portion of this is called centrate, a liquid heavy in nitrogen that looks like crude oil.) Eight of the 14 wastewater plants in NYC have dewatering facilities and six do not. The sludge boats transport liquid sludge from those six plants to the eight wastewater treatment plants with dewatering facilities, to complete the process.

The Captain shows us the controls

The first step involves the “digestion” (hence the digester eggs at Newtown Creek) of raw sludge in oxygen-free tanks, where it is heated and mixed for several days. This process stabilizes the sludge by converting most of the organic material into water, carbon dioxide and methane gas. The “digested” sludge is then pumped through giant hoses onto the sludge boat, to be taken to one of the eight dewatering plants. At the dewatering facility, the sludge is sent to centrifuges which remove most of the water. Once the sludge is treated and dehydrated, it turns into cake and either gets sent out to landfills or beneficially re-used as fertilizer. As Steve told us, NYC’s wastewater treatment plants use physical, chemical and biological processes to remove more than 90% of the organic material in the sewage.

Read more about the wastewater treatment process and how sludge is treated here.

The engine room

A crew of six, including Captain Reil and an Engineer, Assistant Engineer, Mate, and two Sailors, make 7-10 trips a week, and spend quite a lot of time on board. In addition to the Captain’s office where he mans the boat, the engine room, and the control pump room, the boat also has a fully equipped galley and conference room.

Our favorite color (see our new OHNY Weekend buttons)!

Before 9/11, the North River Plant had regular public tours on Tuesdays but has since had to stop those tours. Lucky for you, the Motor Vessel Red Hook will be docked (although not at North River) and available to tour during the upcoming 8th Annual OHNY Weekend! Look for the tour in the OHNY Weekend event guide and online listings, coming in late September!

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