Tunneling for new water pipe

Work continues on the city’s Wastewater Treatment Plant (WWTP) Outfall Relocation project. From the plant, a new pipe will go 1,631 feet to the shoreline, where the pipe will reduce to a 42-inch outside diameter pipe for 1,030 feet with an 86-foot diffuser angled to better match the bidirectional current. The total length of the pipe will be 2,661 feet from the plant continuing into Guemes Channel. The new pipe will be east of the current outfall, terminate in deeper waters farther from the shoreline, and be able to convey larger effluent volumes. Marine and shoreline construction has been completed. The project has changed the method of construction from blasting to tunneling for the section of pipe under 3rd Street and U Avenue. The contractor is currently working on opening the manhole #1 shaft, which also serves as the launch pit for the tunnel boring machine. Overhead utility relocation work is scheduled to be completed in April. (Photos from U Avenue tunneling site. Tunneling contractor from Canada.)