After decades of operation, the pumps supplying wastewater to the trickling filters at the Cayuga Heights Wastewater Treatment Plant had become inefficient and prone to breakdowns.
To meet permit, two pumps of the three aging end-suction pumps operated continuously, and the third was kept on standby and for backup during routine maintenance or emergency repairs. To balance wear and extend pump life, the backup unit was periodically rotated into service. Despite ongoing modifications and rebuilds, only two pumps remained operational and both were rapidly approaching end of life.
The pumps’ check and butterfly valves had become nearly inoperable. The check valves were designed to ensure unidirectional flow of wastewater, preventing backflow that could damage equipment or disrupt operations. The butterfly valves were essential for shutoff, enabling operators to flow to the pumps during servicing.
The village of Cayuga Heights, New York, rectified the problems by replacing the aging pumps with three Wilo-Rexa Norm horizontal end suction pumps and by replacing the failing check and butterfly valves with high-quality, long-lasting valves from Flomatic.
Urgent need
Built in 1952, the Cayuga Heights treatment plant (2.0 mgd design, 1.5-2 mgd average) serves its home village plus the village of Lansing and small portions of towns of Lansing, Ithaca and Dryden. The trickling filters provide biological treatment and help with phosphorus removal.
Recognizing the urgency of the pump situation, plant contract plant operator YAWS Environmental issued an emergency contract and engaged W2O Pump & System Services, a vendor with extensive experience in pump and valve selection.
“YAWS was very concerned about the condition of the equipment,” says Dereck Withey, owner of W2O. “If either of the two remaining pumps failed, the system would not be able to send enough wastewater to the trickling filters to meet permit requirements.”
Having worked with W2O and Withey for a decade, plant lead operator Mike Albro felt confident in allowing their team to make critical decisions about equipment replacement. “W2O is my go-to when I need a dependable solution,” Albro says. “They’ve handled our routine service and emergency work for years. I trust their guidance and know the decisions they make will be reliable.”
Making upgrades
W2O selected and installed three Wilo-Rexa Norm pumps to replace the old end-suction units. The choice was based on the pumps’ reliability, ease of installation and ability to meet plant performance needs. W2O also replaced the check and butterfly valves with valves from Flomatic chosen for their suitability in wastewater systems with large solids. The valve upgrade included:
12-inch AWWA C517 Flo-E-Centric plug valves to replace the butterfly valves on the suction side (with handwheels) and the discharge sides (with chainwheels)
10-inch lever and weight swing check valves with air cushions installed in a vertical orientation
The valves were designed to meet and exceed AWWA C508. Withey specified air cushions with the swing check valves to prevent water hammer, a pressure surge caused by rapid change in flow velocity.
“The pumps are VFD-driven, but in the event of a power outage, the VFD wouldn’t slow the pump down,” says Withey. “That creates the risk of water hammer and slamming. The air cushion protects against that, absorbing the slam and preventing hammering.”
Effective solution
The valve upgrades resolved the sealing failures in the previous butterfly valves and the unreliable operation of the original check valves. “Working together, YAWS and W2O were able to install the new pumps and valves to prevent a major system failure,” says Albro.
“Our wastewater treatment plant discharges directly into Cayuga Lake, so maintaining proper equipment functionality is critical. The trickling filters provide biological treatment, and without them we would only be chlorinating and discharging. These pumps and valves play an essential role in our treatment process.”
W2O’s trust in Flomatic valves extends beyond the emergency project. “We standardize their valves,” Withey says. “We’ve never had a warranty claim or an issue with any Flomatic valve we’ve installed. I’ve been in the industry for 18 years, and they offer better customer service and responsiveness than any valve manufacturer I’ve worked with.”
He recalled an early experience with the company’s support. “When I started this division at W2O, I ordered a Flomatic pressure relief valve through another distributor but accidentally received a pressure-sustaining valve instead.
“It was an emergency job, and later that evening I was able to connect on a call with Flomatic’s president. He walked me through how to modify the valve to make it work for our application, allowing us to get a well pump online.”
With the new pumps and valves in place, the Cayuga Heights treatment plant is now better equipped for long-term reliability.
