The Chambers Creek Regional Wastewater Treatment Plant near Tacoma in Pierce County, Washington, provides wastewater management, collection, and treatment services to about 252,000 customers who generate an average of 19 million gallons of wastewater per day. It also uses that waste to produce a portion of its own energy. The facility is currently undergoing an expansion that will meet the wastewater treatment needs of the growing population beyond 2025 while concurrently offsetting some of its energy needs (instead of consuming energy from external sources). The expansion will include new digester-gas fueled steam boilers to heat the plant and two additional anaerobic digesters, which will increase the production of methane gas used for electricity in the fertilizer manufacturing process According to a Seattle Daily Journal of Commerce article by Tom Paul of Mortenson Construction, “The energy produced at Chambers Creek will be used to heat the plant year-round and will support the creation of SoundGRO fertilizer. Using fertilizer like SoundGRO made from biosolids is a safe and effective way of closing the loop and recycling natural resources.” 

Project start: September 2012 Estimated completion: Spring of 2016 Capacity expansion from 28.7 MGD to 43 MGD