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King County
Executive Office

Ron Sims, King County Executive 701 Fifth Ave. Suite 3210 Seattle, WA 98104 Phone: 206-296-4040 Fax: 206-296-0194 TTY Relay: 711
Image: King County Exeutive Ron Sims, News Release

Sept 10, 2008

Video: Smooth sailing for Brightwater outfall pipelines

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Part one Part two

pipeline in transitNarrator says:

It may be the longest item to ever float down the Snohomish river. This is one of the two-one mile long, deep water marine outfall pipes that will bring treated wastewater from the Brightwater Wastewater treatment plant to Puget Sound. The pipelines were constructed at the Port of Everett and stored in the river until it was time to connect them to the onshore system at Point Wells. Tug boats and barges guided the pipe, which is just more than five feet in diameter past the Everett Marina on its 17 mile journey to Point Wells, to be connected to the onshore pipes.

When Brightwater begins operating in 2011, highly treated wastewater from the state-of-the-art plant will be discharged through this outfall pipe, which will be 600 feet deep and a mile offshore. The advanced membrane bioreactor technology at Brightwater treats wastewater seven to 10 times cleaner than conventional treatment processes, to the state’s highest reclaimed water standards and supporting the state’s Puget Sound cleanup strategy.

It took more than 12 hours to tow the pipe to Point Wells and before the sun came up crews had the pipe roughly in position and began the alignment and attachment process to the onshore pipe.

King County selected this outfall location for Brightwater after years of environmental review that included detailed study of Puget Sound oceanography and marine biology as well as an extensive permitting process involving state and federal agencies.

The white concrete collars that span the pipe will help anchor it to the bottom of the Sound when it is completely submerged. To get the big pipe underwater, water is pumped into it to slowly flood it and lower it to the sea floor. The submergence process is slow and careful to make sure the pipeline lays down where it should and doesn’t break on the way down. Crews worked diligently to keep the pipeline in alignment as tides changed throughout the day and huge ships continued to use the channel on their way to and from the sea.

Although the pipe is flexible, submergence had to go slow because the pressure on the pipe is tremendous. If the pipe submerged too fast it could break. So it went down one section at a time, guided by a laser to keep it in alignment. We’re going to speed up the process just a bit so you can see what it looked like from the shore.

As the sun went down there were just a few hundred feet of pipe left to go and tug boats pushed the final section into alignment. This is where the pipe will settle.

Surrounded by darkness, consumed by the waters of Puget Sound, the last of the pipe disappeared below the surface off the coast of Richmond Beach, roughly 15 hours after the submergence began, most likely never to be seen again.


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  Updated: March 17, 2010