FOR IMMEDIATE RELEASE11-74
August 1, 2011
Farrell Sklerov/Michael Saucier (DEP) (718) 595-6600
Susan Craig/Chanel Caraway (DOHMH) (347) 396-4177
Update on North River Wastewater Treatment Plant Fire and Impacts
Overview of Incident
The North River Wastewater Treatment Plant was taken offline on Wednesday afternoon, July 20, following a four-alarm fire in the engine room that started at approximately 11:45 am that morning. At approximately 5:15 pm Wednesday, untreated wastewater started to be directly discharged into the Hudson River. The North River plant has been in operation since 1986 and treats an average of 120 million gallons of wastewater a day from Manhattan’s west side from Bank Street through northern Manhattan.
Status of Plant Operations
On On Friday, July 22, DEP made significant progress in making the plant operational by bringing two engines back online and, as a result, all untreated discharges into the Hudson River, stopped Friday night as of approximately 9:30 pm. Saturday morning, July 23, at approximately 5:00 am, an electricity feeder that supplies power to the North River Wastewater Treatment Plant went offline because of an electrical utility manhole fire. Con Edison was able to isolate the failed feeder, which helped DEP restore internal power. Both engines started again in less than an hour, but as a result of the power interruption, a pump connected to one of the engines did not take flow for several hours due to a mechanical issue related to the power stoppage. Because of this, the plant temporarily was able to treat roughly 104 million gallons a day of wastewater with primary treatment and chlorine disinfection; while the second pump was offline, untreated wastewater was discharged into the Hudson River at a rate of roughly 15-25 million gallons a day. The second pump was restored to service at approximately 2:00 pm Saturday afternoon, and the rate of untreated discharges quickly decreased until they stopped completely at approximately 3:30 pm on Saturday. Since then, no dry weather discharges have occurred.
All health advisories were lifted on Thursday, July 28. Please refer to the Environmental, Health and Community Impacts section of this release for more information.
DEP is still working around the clock to stabilize the operations that have been restored and put affected systems back in working order. Of the plant’s five engines used to pump wastewater into the facility, only two engines need to be operating during dry weather to handle the wastewater flow into the plant. On Wednesday, July 27, DEP successfully restarted a third engine at the plant, providing critical redundancy during dry weather and adding additional capacity during storms. As a backup in the event of further operational disruptions, and to increase treatment capacity during wet weather, DEP last week installed additional pumping system in case any further issues with the existing system arise. That installation is now fully online, providing an additional 24 million gallons a day of pumping capacity. With three engines online and the supplemental pumping capacity that has been installed, DEP has operated with nearly full wet-weather pumping capacity at North River since the end of last week.
Full secondary treatment is also now online. Early last week, two of the three critical systems necessary to achieve secondary treatment, aeration tanks and final settling tanks, come online and were in operation. The third system—aeration achieved by blowers that supply oxygen to the process—was partially operating, with two of the three blowers needed to achieve secondary treatment currently online. On Sunday, July 31, a third blower was restored to service—the final step to achieving full secondary treatment at North River. Though only two blowers were in operation until yesterday, DEP has been averaging federal wastewater treatment standards for Total Suspended Solid Removal and Carbonaceous Biochemical Oxygen Demand—a measure of how much dissolved oxygen in a waterway gets depleted by sewage—since Monday, July 25.
Because the plant has enough pumping redundancy with the addition of the third engine and back-up pumping systems that were installed, DEP deactivated small “pump arounds” that were temporarily pumping wastewater flow out of an 84-inch sewer at West 117th St. in Manhattan to a 42-inch sewer at Frederick Douglass Boulevard and 117th, which flows to the Wards Island Wastewater Treatment Plant.
In addition to an investigation of the cause of the July 20 fire currently under way by FDNY, DEP has commissioned an independent review of the incident to learn what went wrong, steps the agency can take to prevent similar incidents in the future, and to generate any other recommendations for operational or safety improvements at North River, or any one of the city’s 13 wastewater treatment plants.
Environmental, Health and Community Impacts
On Thursday, July 28, the New York City Health Department lifted the beach pollution advisory for Sea Gate in Brooklyn as well as the beach closure notices for South Beach, Midland Beach and Cedar Grove Beach in Staten Island. At the time, the most recent water quality sampling indicated that bacteria levels found at these locations and in New York Harbor had returned to acceptable levels. Additionally, the Health Department determined that recreational activities could resume in the Hudson River, the East River from the Robert F. Kennedy Bridge to Verrazano Bridge, the Harlem River and the Kill Van Kull to the Goethals Bridge, making these waterways fit for recreational activities that entail possible direct contact with water. Consuming fish caught from these areas was also deemed permissible, provided that individuals follow the New York State guidelines for consumption of fish caught in New York City waterways. That information can be found here.
Warning signs at beaches and kayak launches were removed as a result. Specific beach information continues to be available to the public through website postings at the City’s beach website www.nyc.gov/health/beach, at www.nyc.gov under NYC Right to Know, and at www.nyc.gov/health, the City Information Hotline 311, and those who have signed up to Notify NYC will receive up to date status information relating to public beaches via Twitter, RSS, email and SMS.
In the event of rainfall that would trigger a wet weather advisory, the Health Department will issue standard wet weather advisories for public beaches through 311, Notify NYC and its Web page. Descriptions of wet weather advisories can be found here.
DEP and the Health Department continue to take samples in the harbor and at permitted beaches to ensure that bacteria levels remain within acceptable ranges. For the most up-to-date information, go to the NYC Health website at www.nyc.gov/health, the DEP website at www.nyc.gov/dep, or call 311. Individuals can also receive proactive alerts by signing up through 311 for Notify NYC, the city’s official source for information about emergency events and important city services. Riverbank State Park, located atop the treatment plant, is open. Westchester County and New Jersey DEP are also performing water sampling and water flow modeling to determine any impacts on their rivers and beaches.
Because all public health advisories have been lifted and the plant has resumed full operations, this update will be the last routine advisory on the status of the North River Wastewater Treatment Plant fire and impacts. DEP will notify the press and public if there are any significant status changes at the plant or related health impacts when they arise.
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