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Architecture & Engineering

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January 23, 2017

National finalist: Gold award
Waste and stormwater
Brown and Caldwell

Photo courtesy of Brown and Caldwell
Expansion work took place during the 2015 U.S. Open golf tournament at nearby Chambers Bay.

Project: Chambers Creek Regional Wastewater Treatment Plant expansion
Client: Pierce County Public Works and Utilities

Public utilities across the country are struggling with aging facilities that need major renovations at a time when water quality regulations are tightening along with local government budgets.

Brown and Caldwell won this gold award because they were able to make the impossible possible and in the process far exceed expectations for the client, Pierce County Public Works and Utilities, as well as the citizens who need the public services.

The Chambers Creek Regional Wastewater Treatment Plant is located on 180 acres within a 920-acre regional park with 2.5 miles of marine waterfront on Puget Sound. The Chambers Bay golf course, also in the park, was the site for the 2015 U.S. Open tournament. In addition, the park shelters a wetland/watershed reserve.

Great credentials for a public park, yes, but with a projected service population increase of at least 130 percent over the next 30 years, some serious planning and renovations were needed. Not only did Pierce County need to upgrade its wastewater treatment plant, but it also needed to plan for continual tightening of environmental regulations as well as the eventual need for even more expansion of service.

This is when Brown and Caldwell (BC) entered the picture. First, they designed an integrated facilities plan spanning 30 years that provides the county with a clear strategy for adjusting the rate of level-of-service improvements in tune with regulatory changes, public demand, and the need to create cutting-edge technology to remove contaminants from the water.

Then BC tapped a relatively new proprietary technology developed at the University of Innsbruck in Austria called Demon. This technology treats high-strength ammonia streams through “deammonification,” a process where naturally occurring bacteria remove ammonia from wastewater with minimal energy input.

BC and Pierce County conducted one of the first pilot tests of the technology in the United States, proving its efficacy as well as the substantial environmental and economic benefits the county could realize. In fact, Demon enabled the county to reduce the size of the biological treatment system by 20 percent and cut chemical and oxygen demands by 50 percent and 25 percent, respectively.

Leading up to the facilities planning effort, BC conducted a plant performance test that resulted in a re-rating of the plant’s National Pollutant Discharge Elimination System permitted capacity from 18 million to 31.7 million gallons per day without any capital expenditures, saving the county more than $50 million.

An interesting side story to this project is that the plant renovations took place during the 2015 U.S. Open golf tournament at Chambers Bay. With 30,000 daily visitors plus logistics for a national sporting event, construction was carefully coordinated around a two-month window in early summer 2015 with no visible construction, limited traffic access and no off-site impacts. In fact, during the event, the project’s construction offices were even used as a security command post.

This project ultimately pioneered a model for sustainably co-locating community infrastructure within a highly visible and publicly cherished recreational area without compromising the utility’s ability to provide a high level of service.

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