Pollution levels lower than reported
Biologist admits error in estimate of PCB levels in Spokane River from sewage plant discharge
OLYMPIA – The Spokane River has some of the highest levels of a cancer-causing pollutant in the state, and the county’s new wastewater treatment plant will put more of that chemical into the water, an expert hired by an environmental group said Tuesday.
But under sharp questioning from an attorney representing the county, environmental biologist Peter deFuhr admitted his math was wrong on some computations and his earlier assumptions about the level of polychlorinated biphenyls from the plant were high. The new plant, he added, does a much better job of removing PCB than the city’s treatment plant, which before 2011 was processing some 8 million gallons of county sewage each day.
Less PCB in the Spokane River is a good thing, right? attorney John Nelson asked.
“That’s an impressive performance … and a very good thing,” conceded deFuhr, an expert hired by the Sierra Club and the Center for Environmental Law and Policy, which are challenging the new treatment plant’s permit to discharge the sewage it cleans into the river.
Rather than discharge that treated water into the river, they want the county to reclaim and reuse it, possibly for industrial purposes.
Earlier in the day, deFuhr had told the state Pollution Control Hearings Board that some PCBs can cause cancer, mimic or inhibit estrogen, and interfere with brain development in children. They were once common industrial chemicals used to cool and insulate motors and lubricate machinery, until being severely restricted under a federal pollution law in 1979.
But even though they are mostly banned, they are hard to break down and remain in the environment, building up in fish, shellfish and other aquatic life.
The concentration of PCB increases as the Spokane River flows out of Idaho to Long Lake, from the runoff of rainwater and snow melt, municipal sewage treatment and industrial sources of wastewater like Inland Empire Paper Co. and Kaiser Trentwood. The paper company is owned by Cowles Co., which also owns The Spokesman-Review.
The state Department of Health has issued a series of warnings about eating fish from different segments of the river, deFuhr said. It advises against eating any fish caught between the Idaho border and Upriver Dam. In other stretches, the agency advises against eating certain species and limiting consumption of other species to as seldom as once per month.
Discharge from the new treatment plant will contribute to the pollution, he said: “It will discharge PCBs, and it is discharging PCBs.”
Nelson challenged deFuhr’s assumptions in reports he’d prepared, first pointing out an error in basic arithmetic the biologist made when converting chemical concentrations from liters to gallons that dropped the level of pollution by about 20 percent.
“Sitting here today, I can’t explain how I made that math mistake,” deFuhr said.
His earliest conclusions were made before there were any test results from the new plant, so he used figures from the city of Spokane and Liberty Lake treatment plants. But those don’t have as sophisticated a system as the new county plant, which is releasing only about 2 percent of the amount of PCB as in those early conclusions.
Nelson also questioned the way the biologist analyzed recent data from the new plant, and what comparisons he made with test samples designed to show whether the PCB was present in the surrounding environment or the lab equipment.
The PCB going into the river would still be far less than when county sewage was being pumped through the city treatment facility, Nelson said.
Although deFuhr described the new plant’s ability to clean PCB from the water it treats as “remarkable,” he said the city treatment plant won’t be required to reduce its discharge.
Environmentalists say the county, which is removing septic tanks in suburban areas, will still be able to pump as much as 10 million gallons of its sewage to the older city treatment facility. If the county would give up that right, Rachael Paschal Osborn of the Center for Environmental Law and Policy said, “we wouldn’t be challenging the permit.”
Testimony is expected to finish today. The board may take a month or more to make its ruling.