A four-year, $239 million expansion to the Chambers Creek Regional Wastewater Treatment Plant near Tacoma comes at just the right time.

Not only does the expansion in University Place add energy-generating capacity to the waterfront facility in University Place, Washington, but it also does so as the facility expects to reach capacity this year.

Currently, the Chambers Creek facility provides wastewater management, collection and treatment services to about 252,000 customers generating 19 million gallons of wastewater on average each day. Without the expansion, the plant would have maxed out this year, but the Mortenson Construction project that started in 2012 will push capacity to meet county growth needs through 2025.

The expansion not only adds capacity, but it boosts the plant’s environmental profile, substantially reducing energy consumption and increasing the production of the locally popular SoundGRO fertilizer, which has been sold out for months. The expansion adds two more anaerobic digesters—totaling five digesters for the site—to help curb the demand for external power. Digested gas runs boilers rather than requiring the use of natural gas or other external power.

Using five anaerobic digesters will allow the heating of Chambers Creek Regional WWTP year-round without added power.

As part of the expansion, now in its final stages, treated water gets disinfected by UV radiation, breaking up DNA chains in bacteria to prevent reproduction. Reclaimed water is also used to water nearby Chambers Bay Golf Course, home of the 2015 U.S. Open.

Follow Tim Newcomb on Twitter at @tdnewcomb.