Dredging resumes to protect Corvallis water
CORVALLIS — A pulp mill company spent $1.9 million last year carving a channel through a gravel bar in the Willamette River so it could discharge waste from its plant upstream of Corvallis without creating a foul-smelling, coffee-colored plume.
But this spring floods choked the channel with gravel, so Cascade Pacific Pulp has begun dredging again in the river that supplies about 70 percent of the city's drinking water.
The work began Monday, the Corvallis Gazette-Times reported, and was expected to take as long as 10 days and cost $100,000.
Two years ago, the conservation group Willamette Riverkeeper raised concerns about the plume when a gravel buildup kept water out of a zone where the effluent gets diluted before heading downstream.
The group threatened a suit under the federal Clean Water Act, and the two sides reached a settlement that called for a major dredging project to get more water into the zone.
The site is in Linn County, about 15 miles south of Corvallis.
The company has an intake and discharge facility that serves the pulp mill and an adjoining tissue paper plant owned by Georgia-Pacific.
Cascade Pacific general manager Pat Rank said he hopes the dredging will suffice, at least for the short term. The spring floods were unusually heavy, he said.
The company is exploring longer-lasting solutions, he said, and is also concerned about bringing a more reliable flow of water to its intake pipe.
Riverkeeper director Travis Williams said he has suggested the company move a mechanism called a diffuser pipe to a deeper spot to get more water in the mix. But he is skeptical that a mixing zone can ever be adequate for disposing large quantities of treated industrial wastewater.
Information from: Gazette-Times, http://www.gtconnect.com