By Michael Kopper, Centrisys

It takes big ambition to tackle big projects and make them a success. A leading North American manufacturer of decanter and thickening centrifuges and dewatering systems, Centrisys Corporation was eager to take on the $67 million comprehensive energy-efficient upgrade at two of New York City’s largest wastewater treatment plants. As part of a series designed to improve pollution control and treatment efficiency, the NYC Department of Environmental Protection chose to install thirty-two American-made CS26-4 Centrisys decanter centrifuges. 


Midwest-based Centrisys Corporation provided the New York City Department of Environmental Protection with thirty-two CS26-4 Centrisys decanter centrifuges to improve the efficiency of the wastewater treatment process at two high-use locations:

  • The Wards Island Wastewater Treatment Plant is the second largest of the fourteen wastewater treatment facilities in New York City, serving nearly one million people.
  • Hunts Point Wastewater Resource Recovery Facility in the south Bronx cleans more than 200 million gallons of wastewater produced by 700,000 residents every day of the year.

The Centrisys engineering team integrated a centrifuge stand, diverter gate, and interconnecting pipework into the plant design. These design elements created a “drop in place” centrifuge system, allowing for easy integration with only few minor modifications to the existing floor plan.


Centrifuges are used in the wastewater treatment process to dewater solids (sometimes called “sludge”) after anaerobic digestion. The older centrifuges were removed and replaced with newer models in groups of four to ensure the continued operation of the plant throughout the project that began in 2015. The new Centrisys centrifuges will consume 60 percent less electricity, and reduce 826 metric tons of greenhouses gases annually between the two plants. To date, the upgrade has resulted in savings of $1.1 million per year in power, polymer, and biosolids disposal costs and have greatly improved New York City’s dewatering operational efficiencies. 

With more than thirty years in business, the NYC project exemplifies what our team of engineers can do. As a company, Centrisys takes great pride in our technology. Putting systems in place that have an evolving impact on the communities it serves while reducing the environmental footprint and cost of the wastewater treatment process, is of utmost importance. 

The Centrisys engineering team integrated a centrifuge stand, diverter gate, and interconnecting pipework into the NYC plant design. These design elements created a “drop-in-place” centrifuge system, allowing for easy integration with only a few minor modifications to the existing floor plan. 

In July 2017, the Wards Island Process Control Laboratory conducted a test that showed Centrisys’s CS26-4 centrifuge installation demonstrated better than specification performance results.

Field acceptance test results at Hunts Point Wastewater Treatment Plant from spring of last year also show the benefits of the Centrisys CS26-4 centrifuge.

Additional plant updates included: 

  • Ancillary equipment, including sludge and polymer feed pumps with associated instrumentation and controls. 
  • A new build of an operator workstation equipped with an online solid monitoring system and a new motor control center.
  • Replacement of piping, specialized pumps, valves, and other wastewater equipment that work in direct support of the centrifuges. 
  • Additionally, lighting fixtures in the centrifuge room, the control room, the conveyor room, and the polymer bulk storage area will be upgraded to more energy-efficient models. 
The data acquired is from the Wards Island Process Control Laboratory. The New York DEP randomly selected two Centrisys CS26-4 decanter centrifuges #5703 and #5705, from the 10 installed centrifuges at the time, to conduct the 48-hour performance test.
Prior to the field acceptance test, it was agreed to run only one Centrisys CS26-4 decanter centrifuge #5707 to validate previous acceptance testing. The previously installed centrifuge was also operating.


Andy Torres is the Centrisys NYC project manager who assisted with the project upgrade and worked most closely with the municipality. 

“Although this was a challenging project due to the age of the older system, design of the facilities, the amount of energy required, and the sheer number of individuals dependent on the technology to continue working throughout upgrades, we knew our decanter centrifuges were the ideal solution for NYC,” says Torres.


Michael Kopper is president and CEO of  Centrisys/CNP. Centrisys is a USA manufacturer of dewatering centrifuges, sludge thickeners, and provides global centrifuge service, repair, and parts for all decanter centrifuge brands. CNP, a division of Centrisys, supplies nutrient recovery and advanced biosolids treatment systems for phosphorus recovery and thermal hydrolysis processes. For more information, visit

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