Exploring the site: the Clarifier

Tue 25 Oct 16

Clarifier and Basalt Habitat

Get ready - riverwalk design concepts are coming this November! Leading up to that, we are highlighting some key site elements that you will see in the design concepts, including the Pipe Tunnel, the North Riverbank, the Clarifier, the Service Yard, and the Hawley Powerhouse Foundation.

Our design team is investigating ways to reuse, enhance, or re-purpose structures and elements from the old mill and PGE dam; along with opportunities that come from removal. Today, we focus on the Clarifier, a large concrete tank that was used to treat effluent from the paper-making process.

The clarifier was built in 1967 by Publisher’s Paper Company after the state, under Governor Tom McCall, ordered clean up of the Willamette River. Two years later, the Oregon Department of Environmental Quality formed, and in 1972, the Clean Water Act was passed. The clarifier is 160 feet in diameter and is built next to the PGE dam, in roughly the same location as John McLoughlin’s early mills.



In the riverwalk opportunities report, our design team examined the clarifier and found the following opportunities and constraints:


  • Highly adaptable; flexible potential for re-use or habitat
  • Significant industrial structure
  • Unique site element to interpret
  • Impressive scale and size


  • Blocks the floodway
  • Occupies valuable space for habitat restoration
  • May be difficult and costly to remove
  • May be difficult to restore native basalt after removal


In November, you will see different options for the clarifier area in the riverwalk design concepts. We can't wait to hear what you think!

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