Human activities, such as industrial production, transportation and day-to-day living, are sources of many contaminants that flow into the Columbia River, according to Jennifer Morace, a hydrologist with the U.S. Geological Survey.
A recently completed reconnaissance study, conducted with Morace as the principal investigator, detected more than 100 toxic contaminants in water samples collected from wastewater-treatment-plant effluent and storm runoff in Hood River and eight other cities that line the Columbia River in Oregon and Washington.
The nine cities surveyed, in downstream order, are Wenatchee, Richland, Umatilla, The Dalles, Hood River, Portland, Vancouver, St. Helens and Longview.
Hood River, like most of the other sites, was found to have traces of pesticides, pharmaceuticals, personal care product chemicals, flame retardants, mercury and cleaning solutions in post-treatment effluent and storm water discharges.
The top six pharmaceuticals found in post-filtration wastewater effluent from Hood River included codeine (pain killer), diphenhydramine (allergy medicine), diltiazem (blood pressure medicine), carbamazepine (mood stabilizer and anticonvulsant), caffeine and trimethoprim (an antibiotic).
“Many of these toxic pollutants are not removed by normal purification processes in municipal wastewater treatment plants, and f or that reason it is wise to think twice before washing or flushing anything down the drain that can harm the environment,” said U.S. Geological Survey Director Marcia McNutt.
“After all, the fish from the Columbia River find their way to many dinner plates; thus we want to be sure that their home waters are as clean and healthy as possible.”
None of the agencies cooperating in the recent study have issued warnings or advisories for humans who use the river for recreation.
According to the USGS, “The amounts found in the study would be small when diluted by the Columbia River, but could be significant locally, near the sources.”
“Many of the compounds we detected are assimilated by lower organisms and concentrated up the food chain to top predators, including humans,” Morace said.
The USGS study, done in cooperation with Columbia River Inter-Tribal Fish Commission and the Lower Columbia Estuary Partnership, will be used to help water managers and policy makers in the lower Columbia basin make decisions about how to proceed with toxin-reduction activities.
“Hundreds of fish and wildlife species, including 12 stocks of threatened and endangered salmonids, rely on the Columbia River ecosystem for their food sources and habitat, so toxic contamination is a significant concern in the basin,” Morace said. “We need to know what’s getting into the river and where it’s coming from. This study was a first step toward finding out.”
The wastewater-treatment plant study analyzed for 210 toxic compounds, and 112, or 53 percent, were detected.
Most of the compounds detected in the treatment-plant effluent were found at all of the plants, whereas the compounds in storm runoff varied among locations. This result is expected given the variety of sources for the runoff waters.
“Our partnership with the USGS has led to key insights that have helped us understand the scope of toxic contamination in the Columbia River, a key step to reducing contaminants and improving water quality,” said Debrah Marriott, executive director of the Estuary Partnership.
“Toxics are among the largest threats to the Columbia River ecosystem,” said Paul Lumley, executive director of the Columbia River Inter-Tribal Fish Commission. “This report clearly demonstrates what is entering the Columbia River system.
“Now that we understand how toxics have made their way in to our river system, we must take immediate action to address the sources of contamination and begin cleanup,” he said. “As tribal members, we have always been taught that healthy ecosystems and healthy communities begin with healthy water.”
The results of the study can be viewed in U.S. Geological Survey Scientific Investigations Report 2012–5068, “Reconnaissance of Contaminants in Selected Wastewater-Treatment-Plant Effluent and Stormwater Runoff Entering the Columbia River, Columbia River Basin, Washington and Oregon, 2008-10,” which can be accessed online at http://pubs.usgs.gov/sir/2012/5068/.