Construction Update: August 2025

In August the first four critical transmission main tie-ins were completed. Treated water is now being rerouted around the project site. This was an important step to complete before the contractor could begin demolishing the slow sand filters.

The construction crew completed the final connections to a new bypass pipe to re-route water around the new water treatment plant site. In order to minimize the amount of time that the transmission main would be offline, the crew worked around the clock, doing double shifts, to make the connection within 48 hours.

For the fourth tie-in, crews first excavated under the century-old 60-inch treated water transmission main that is currently within the footprint of the future plant. The tie-in involved installing a tee connection on the existing pipe to reroute the water. A concrete thrust block will hold the pipe in place as the water makes a 90 degree turn to flow through the existing 60-inch transmission main.

Construction workers formed the thrust block by building a structural form and placing rebar around the pipe to pour concrete.

Then, the existing pipe was cut off and drained. Two new sections of pipe, each weighing thousands of pounds, were lifted by crane into the excavation. The first section connects to the existing facility and will remain in service through construction. The second section was capped to connect to the new treatment plant in the future towards the end of construction. Each section was fitted to the existing pipe and bolted to the thrust block. The rods connecting the end cap to the thrust block helped restrain the initial thrust of water, which was so powerful it could blow apart the pipe. Once the new treatment plant is constructed, the end cap will be removed to be connected to the new facility.

On August 21^st, another significant milestone was reached when water was turned on in the new chemical injection vault, or CIV. In this photo, taken from the top of the CIV, the two thin pipes emerging from the concrete on the right carry two common but critical additives: phosphate for corrosion control and sodium hydroxide (caustic) for adjusting the pH of finished water.

Now that the CIV is functioning, crews have backfilled the area.

There wasn’t much time to celebrate August’s accomplishments before starting prep work for the next set of tie-ins, which will make space for two new pipes that will deliver raw water to the new plant.