OLYMPIC NATIONAL PARK — The National Park Service will spend at least $3.8 million more to build a possible solution to Elwha River sediment problems that have plagued the park’s Elwha water treatment plant for at least a year.
Brian Winter, Elwha restoration project manager for Olympic National Park, said the federal agency has contracted with Lakewood-based Macnak Construction to build a temporary pump facility adjacent to the Elwha Water Treatment Plant, which lies about 2.8 miles from mouth of the Elwha River.
The temporary facility is meant to take the place of the water treatment plant’s surface water intake while park officials try to figure out why the filters on the main intake have been letting sediment and other debris through to the plant, Winter said.
The sediment was released through dam removal.
The Elwha River Dam demolition was finished in March 2012.
The deconstruction of the remaining 50 feet of Glines Canyon Dam, father up the river, has been halted since last fall while the park has worked to address the sediment reaching the water plant.
Olympic National Park spokeswoman Rainey McKenna said approximately 8 million cubic yards of sediment have moved downstream.
National Park estimates put the total amount of sediment locked up in the two dam reservoirs at 34 million cubic yards, though only a portion of it is expected to flow downstream.
Work should begin again in October, said Olympic National Park Superintendent Sarah Creachbaum.
Creachbaum said the once-210-foot-tall Glines Canyon Dam is still expected to be gone by September 2014.
McKenna said Macnak was given notice to start work Aug. 20, though she could not say what the contractor’s own time line is.
Park officials expect construction of the temporary pump facility to be completed by November.
Winter said the alternate pump facility will allow park staff to shut down the treatment plant’s surface water intake and figure out why sediment, gravel and woody debris has been infiltrating the plant.
Water plant crews have not been able to scrutinize the intake because it is needed to feed the plant river water, Winter explained.
“It’s like working on a car while driving down the road,” Winter said.
The temporary pump facility will not replace the surface water intake because it will use water pumps to draw water into the treatment plant, Winter explained.
These pumps will cost more to operate because the existing intake is fed by gravity, Winter said.
The water pumps will draw water via newly built pipes through new sediment filters into the plant, Winter explained.
The plant was designed to filter sediment-thick river water to a certain degree and pass it along to four downstream users: Nippon Paper Industries USA, the state Department of Fish and Wildlife fish-rearing channel built along the river, the Lower Elwha Klallam tribe’s fish hatchery and the Port Angeles Water Treatment Plant, which provides drinking water for the city.
The plant has been able to provide the quality of water needed by the downstream users, though not the quantity agreed upon before dam removals began.
That has worried Port Angeles officials, because it means that the city must rely on its Ranney well more than expected, and that could shorten the life of the well.
The Ranney well is the city’s main source of drinking water.
Reporter Jeremy Schwartz can be reached at 360-452-2345, ext. 5074, or at jschwartz@peninsuladailynews.com.
