2/9/2012

In November 2002, Bentonite slurry, concrete and rebar framework were all materials used to construct a 50-foot-diameter hole that would become Nicolai Shaft, part of a $1.4 billion project to modernize the Portland, Ore., sewer system. This photo essay shows the efforts that led to this "impressive feat of engineering" that was funded by a city bond offering that increased sewer rates.

Full Story:
Wired.com

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