Tacoma completes $9M floodwall project at wastewater treatment plant

The City of Tacoma will mark the completion of a $9 million project to build a flood wall around Tacoma’s Central Wastewater Treatment Plant during a ribbon-cutting ceremony in June.

During large storm events, the plant receives and treats more than 130 million gallons of wastewater per day before the treated wastewater is discharged to Commencement Bay, according to City officials. A major flooding event at the plant would destroy treatment equipment and would cause millions of gallons of untreated wastewater to overflow into Puget Sound with potentially negative impacts to businesses, wildlife and recreation, City officials report.

The project, which began last spring, involved building a 2,500-foot-long wall that stretches along the outside of the plant, ranges from one to eight feet high, and extends 25 feet below ground. In addition to three manual gates, three hydrostatic lift gates were installed that will operate automatically during a flooding event. The project was paid for using nearly $3 million in utility customer rates, as well as $6 million in Pierce County Flood Control Zone District funds. According to City staff, the project was completed within budget and two months ahead of schedule.

Tacoma’s Wastewater Treatment Plant serves customers in Fife, Fircrest and unincorporated Pierce County — in addition to Tacoma.

City of Tacoma Environmental Services Director Mike Slevin, Pierce County Executive Pat McCarthy, and Tacoma City Councilmember Ryan Mello are scheduled to join local leaders during a ribbon-cutting ceremony at 1 p.m. on Weds., June 3, at the Central Wastewater Treatment Plant, located at 2201 E. Portland Ave., in Tacoma. The event will also include a demonstration of the automatic flood gates.

More information about the Central Wastewater Treatment Plant is available online here.

Tacoma's Central Wastewater Treatment Plant. (PHOTO COURTESY CITY OF TACOMA) — Tacoma’s Central Wastewater Treatment Plant. (PHOTO COURTESY CITY OF TACOMA)

To read the Tacoma Daily Index’s complete and comprehensive coverage of the Central Wastewater Treatment Plant flood protection project, click on the following links: