Case Study: Science on Unregulated Pollution

Columbia Riverkeeper works with people in dozens of communities—from rural to urban—who share the same goals: Protect the health of their families and the places they love. 


Case Study: Science on Unregulated Pollution

Patrick Haluska collecting water quality samples.
Patrick Haluska collecting water quality samples.

Columbia Riverkeeper (Riverkeeeper) volunteers collected samples for a new Oregon Health & Science University study about the pharmaceutical metformin in the Columbia River. The study, led by Dr. Tawnya Peterson, Dr. Joseph Needoba, and Brittany Cummings, draws attention to a relatively new kind of unregulated pollution.

Every day, wastewater treatment plants and storm drains add millions of gallons of wastewater to the Columbia River. This wastewater is usually treated, but the treatment methods are not designed to remove the pesticides, herbicides, flame retardants, personal care products, and pharmaceuticals that can wind up in household wastewater. Collectively, these substances are called Chemicals of Emerging Concern (CECs). The Environmental Protection Agency (EPA) does not generally regulate CECs, even though the EPA knows or suspects that many CECs harm aquatic life.

We know that CECs are going into the Columbia. In 2013, a Riverkeeper-supported study detected CECs in the wastewater of seven sewage treatment plants. Scientists also detected CECs in sediments on the Columbia River bottom in 2012.

But the Columbia is a huge river. With all that water diluting the contamination, can we really detect CECs like personal care products and pharmaceuticals in the Columbia? Yes. In a groundbreaking study in 2014, Dr. Peterson and her colleagues detected, for the first time, personal care products and pharmaceuticals in the open waters of the Columbia. Although the concentrations of most CECs were very low, our ability to detect these contaminants in such a large river suggests that a lot of CECs are entering the Columbia.

Dr. Peterson and colleagues focused their research on a CEC called metformin—a drug for treating Type II diabetes. Metformin, at the concentrations typically found in treated sewage, interferes with sexual development and reproduction in certain fish.

Peterson’s recent work—in partnership with Riverkeeper and funded by Oregon Sea Grant—tracked metformin at several Columbia River sites between The Dalles and Astoria. Metformin appears to be widespread throughout the Columbia. The highest metformin concentrations were typically found downstream of the Willamette River confluence during low flows, but the overall amount of metformin entering the Columbia remained about the same year round.

The good news is this: metformin concentrations in the Columbia are 250–300 times lower than in the studies that demonstrated impacts on fish. Now the bad news: we don’t know if, or how, fish respond to the concentrations of metformin currently in the Columbia. We also don’t understand how mixtures of CECs affect fish and wildlife. Metformin is one of many unregulated chemicals, and Riverkeeper will keep supporting science about how CECs impact the Columbia River.

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