Wednesday, February 20, 2008
With any major project, there are likely to be unanticipated costs. That reality holds true regarding Portland utility PacifiCorp's bid to decommission and remove Condit Dam on the White Salmon River.
PacifiCorp representative Tim Hemstreet came to the Feb. 6 meeting of the White Salmon City Council to discuss what will happen to the water pipeline that serves the city of White Salmon. The pipeline is buried in silt at the bottom of Northwestern Lake, and when the reservoir drains, the line is not expected to withstand the force.
Mike Wellman, director of White Salmon's Public Works Department, said the line couldn't survive removal of the 1913-era dam.
"When the dam is taken out it will be like a big flood event," Wellman said. "Our pipeline is set up pretty high in the silt that has developed over the years. It would definitely take the pipeline out."
To avoid disruption in the city's water service, the water line -- which has been in place since 1937 -- needs to be relocated before the dam removal process begins.
That project is likely to cost serious money, and Hemstreet explained that PacifiCorp realizes it needs to cover the expense.
"We're trying to figure out how to mitigate the impact to the water line that runs under the lake," Hemstreet said. "We'll continue to work with the city in a cooperative relationship that won't impact the city's services. We want to set up a memorandum of understanding that is acceptable to both parties. PacifiCorp seeks to work with the city to fix the water line prior to dam removal."
Hemstreet pointed out there were two relocation options being considered: Either bore a line through the rock underneath the river, or route a pipeline across the bridge that crosses Northwestern Lake.
Wellman said drilling into the rock would be costly.
"Putting the line underneath the river is fairly expensive, and my basic concern is, there is no guarantee it'll work," Wellman said. "Even though boring under the river is a bit cheaper, we're concerned that if something did happen, we would not be able to get there to do anything about it because the pipe is buried in rock. We want a permanent service that's hydraulically equivalent with what's there."
Rather than bore under the river, Wellman recommended moving the 14-inch water line and having it cross using the existing bridge on Northwestern Lake Road.
"That would require about 10,000-14,000 feet of pipe. It's not a small amount," Wellman said. "But we can do it. We have most of the easements. That's the most economical and most beneficial way to serve the city in the future."
Hemstreet said there is no hard deadline to get the line relocated -- despite PacifiCorp's proposed target date of October 2008 for the dam to come out.
"Due to the lengthy permitting process that is still going on, it's very unlikely the project will be completed this year," Hemstreet explained. "The Federal Energy Regulatory Commission has not yet issued a `surrender order,' and it's not known if FERC will recognize our cost caps."
The cost cap Hemstreet referred to stems from a 1999 "settlement agreement" among numerous agencies and jurisdictions. The deal called for the dam to be removed, but for PacifiCorp's obligation to cover related costs set at a maximum of about $21 million.
"We expect to receive a surrender order from FERC, but it may or may not be the same as the settlement agreement," Hemstreet explained. "And we're not sure they will recognize our cost caps. In a surrender order, FERC has never recognized a cost cap before. But we'll have to replace this water line, whatever the cost."
Hemstreet added that moving the pipeline was not figured into the original cost cap number.
The Washington Department of Ecology is among the agencies that still has to issue permits before the dam can come out. WDOE is considering whether to issue a "water certification permit," and sediment samplings have delayed issuance of that permit.
"We found elevated levels of mercury that we believe is naturally occurring," Hemstreet said. "WDOE has asked us to ensure that we would not be creating an adverse impact by releasing water from the dam."
Wellman added that the existing water pipeline is overdue for replacement.
"That pipeline varies in condition," he said. "We're not sure of the condition of the pipe under the river, but originally, it had a 40-year life when it was put in back in 1937."