Commission reviews cavitation fixes for 4th Street lift station; vendor and engineering assistance offered

Ken Bloom, director of public works, updated the commission on cavitation problems at the 4th Street lift station and relayed vendor-supplied troubleshooting steps. Representatives from Smith and Loveless recommended shutting the discharge valve on the pump until the check valve stops pumping, then slowly reopening the discharge valve and observing whether cavitation recurs. Vendors also recommended confirming that suction lines are positioned at least 6 inches off the wet-well floor inside the lift station.

Darren Pope of engineering firm Vierbicher offered to come on-site at no charge to assist with implementing these checks. Bloom told the commission the original impeller installed in 1974 was 7 3/4 inches and has been trimmed over time but that the utility has no record of the current trimmed size; Paul from William Reid suggested having a machine shop trim one of the spare impellers on hand. Commissioners discussed the possible installation of a variable frequency drive (VFD) as another mitigation option. No formal procurement or replacement decision was made at the meeting.