After more than 16 years on the job, influent pump No. 1 at the Sutter Avenue wastewater treatment plant has reached the end of its useful life. So, on Monday, about a dozen workers and two cranes removed the pump from its resting place at the Modesto plant.
That was no small task. The pump weighs about 54,000 pounds, is 8 feet in diameter and more than 40 feet long. It’s essentially a giant screw encased in a cylinder.
The workers and the cranes eventually set the pump on a flatbed trailer attached to a tractor. The tractor-trailer will haul the pump roughly 2,500 miles to Evoqua Water Technologies in Thomasville, Ga., where workers will determine whether it can be fixed or needs to be replaced.
A city report states that Evoqua is the only facility in the nation with equipment large enough to work on the pump, as well as the technical expertise to do the job. The company has repaired other influent pumps for Modesto.
The report estimates it will cost $357,000 to repair the pump and as much as $800,000 for a new pump. The city expects to spend $47,000 for the cranes to remove and reinstall the pump. A Bay Area company provided the cranes used Monday. The money for the project is coming from wastewater fund reserves.
The Sutter Avenue plant has four of these pumps, which also are known as internalift screw pumps. They lie at an angle against the plant’s head works and each day lift millions of gallons of raw sewage about 40 feet into the head works, which is the beginning of the treatment process.
The plant relies on gravity as the sewage flows downhill through the rest of the treatment process.
Modesto expects the three remaining pumps can handle the plant’s needs while the fourth is being worked on.