North Castle Moves Ahead to Upgrade Sewer Plant for Downtown Armonk

North Castle officials are planning improvements to the wastewater treatment plant for the sewer district that serves downtown Armonk rather than opting for the far more expensive facility expansion to accommodate additional downtown development.

Last week, the Town Board agreed to authorize Environmental Design & Research (EDR) of Syracuse, an engineering and environmental consulting firm, to complete final design for the upgraded treatment plant.

The town had previously considered expanding the plant’s capacity from the current 500,000 gallons of flow a day to either 600,000 or 700,000 gallons, but the cost was estimated to be at least twice as much as the projected $4.5 million upgrade project.

Sal Misiti, the town’s director of water and sewer, said the municipality’s Request for Proposal with EDR to improve the treatment process focused on five areas that would not cause the plant to exceed its daily flow capacity while maintaining the mandated nitrogen removal requirements.

He said the five improvements would include adding granular carbon filtration to a remove additional nitrogen from the effluent; upgrading the existing ultraviolet disinfection system; upgrading the sludge thickening equipment to increase efficiency; install a water system using clean plant effluent to complete the facility’s processes, thereby easing demand on the town’s Water District #4; and upgrading three pumping station control panels.

Misiti said the town needs to show the state that it can accept the flow from the projects that may be built and to better control the carbon and nitrogen levels.

“What this does is really polish off our effluent to a greater degree,” Misiti said. “Once we supply that data to the regulatory agencies with higher flows, it won’t be as much as an impact on our current limit of loading on the Long Island Sound.”

Officials are confident that with the upgrade, the town can accommodate the approved projects and those under consideration in and around Armonk that would Sewer District #2.

While Councilman Saleem Hussain asked if the town could look for ways to pare down the upgrade to save some money, Town Attorney Roland recommended the town be more proactive.

“We’re trying to stay ahead of the development that we know is on the heels because that development, once on line, will pretty much cap the plant at capacity, and since we’re not increasing capacity, we need to be confident that the plant will run at its existing capacity, which is 500,000 gallons per day,” Baroni said.

Robert Butterworth, principal at EDR, said the $4.5 million estimated cost were based on historical perspectives, although costs over the past year are much higher because of the pandemic. He mentioned that the firm also estimates to the high side so there aren’t surprises later in the process.

“You want something to come in that we have considered ourselves for some of the worst-case scenarios because we’re developing these costs doing a worst-case scenario,” Butterworth said. “We are trying hard to make sure that as costs come in, they’re lower than ours. Cane we guarantee that? No, but that’s our goal.”

There may also be opportunities from grants from various governmental agencies that could reduce costs by 20 to 25 percent. Then there is always the hope that Congress passes an infrastructure spending plan that includes money for sewer and water improvement projects such as this.

During the Apr. 28 Town Board meeting, officials agreed that they must proceed with the design phase of the project. Councilwoman Barbara DiGiacinto said the proposed upgrade “is not a luxury, it’s a necessity.”

“Make no mistake, it’s something that’s definitely needed,” added Councilman Barry Reiter. “Sal’s put together an incredibly detailed report of what has to be done. There’s the question expenses and costs, obviously. It’s long overdue.”

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