Construction Update: December 2025
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It was a snowy start to winter in Westfield. Despite the snow and holidays, construction crews still made progress on our new plant.
Crews continued placing and installing two new raw water pipes through December. One pipefitter was tasked with climbing inside the 60” pipe to “parge” or seal the seams with concrete.
Indoors, we made progress with optimizing the new Backwash Facility. Specifically, we added new piping to create a “recycle,” which will allow us to send lower flows to the existing and new plant during the backwash process.
Dewatering the south tank (left), then coring a hole through the concrete floor (right).
The Backwash Facility houses three backwash pumps, which keep the rapid sand filters functional and effective by pumping water up through the filters to regularly scour and flush out accumulated filtered material. Completed in fall 2023, this new facility was designed to work with the existing plant and eventually connect to the new one. The redundancy of two underground tanks located directly below the facility (which hold filtered water to use in the backwash process) with a total storage capacity of one million gallons allows for upgrades or maintenance exactly like this. This was not possible with the previous backwash tank (known as the “clearwell”), which was a converted 1920s slow sand filter chamber located on the site of the future plant.
The three new backwash pumps have a limited range in pumping velocity, which is common for such equipment. A wider range of flows is needed, however, to optimize the effectiveness of the backwash process. The newly installed piping will enable lower flows from the pumps by sending excess water back into the storage tanks. To connect the new piping to the Backwash Facility, crews carefully drained and cleaned out the north tank while the plant continued operations using the south tank. They cut a large hole through the concrete slab, prepped and coated it for the new pipes, then hauled in and installed the new pipes. Once the tank was refilled, they moved to the south tank to repeat the process.
Eventually, the new plant will be connected at a junction point located just outside the Backwash Facility. In the meantime, the existing rapid sand filters in the 1974 plant will cleaned at a more effective pace.