WALNUT CREEK, Calif. — Pierce County, Wash., celebrated the groundbreaking of the $353 million Chambers Creek Regional Wastewater Treatment Plant expansion on Nov. 15 in University Place. The expansion integrates the cutting-edge nitrogen removal technology, DEMON®, as well as alternative delivery approaches and construction management by Brown and Caldwell to limit impact to the adjacent golf course, which will host the U.S. Open in 2015.

Tim Ramsaur, Pierce County’s Wastewater Utility Manager, said the day “marks the start of a project that has been in the works for several years, and we are pleased to move forward with the first construction package of this expansion.”

With the service population of Pierce County expected to increase by 130 percent over the next 30 years, Brown and Caldwell was charged with developing an expansion plan that could accommodate the full range of potential effluent limitations.

“The expansion project is crucial to our efforts to serve our customers, protect the environment, and support economic development,” said Pierce County Executive Pat McCarthy. “We are building for the future now to save money in the long run, and our proactive approach means we will increase wastewater treatment capacity in time to meet the needs of Pierce County communities.”

Areas of the plant to be upgraded, renovated, and expanded include: utilidor and solids stream improvements, liquid stream improvements, plant laboratory, maintenance and administration buildings, odor control and primary sedimentation tank rehabilitation, and biosolids and energy recovery. The plant upgrade from carbon to nitrogen removal also provided the opportunity for junior engineers and company leaders to conduct DEMON® pilot studies, utilizing the industry-leading anammox process. By using anammox, Pierce County stands to save $6 million while reducing the size of the aeration basins and enjoying other benefits.

Brown and Caldwell’s program manager, Chris Cleveland, praised the county for having the foresight and courage to take on a project of this magnitude. “The technologies, GC/CM process, financial planning, and asset management practices are all on the forefront of what is happening in other sewer utilities across the country.”

One of the unique challenges of this project is that the plant is located adjacent to the Chambers Bay Golf Course, the location of the 2015 U.S. Open. Construction will need to be carefully coordinated around a two-month window in early summer 2015 with no visible construction, limited traffic access, and no off-site impacts. Because of this and other challenges, the county selected a GC/CM contracting approach with approval from the state’s Capital Projects Advisory Review Board. Mortenson will lead construction, with up to 400 tradeworkers employed in various aspects at the peak of construction. Brown and Caldwell will provide construction management services through the life of the project.

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