Scientists discover pharmaceuticals in wastewater flowing into the Puget Sound.
Story by Alexa Eddy | Photos by Katy Cossette
Not everything traveling down the drain disappears. Researchers estimate over 100 kilograms of pharmaceuticals — drugs like OxyContin, cocaine and Valium — enter the Puget Sound every day. Scientists are beginning to look into methods to reduce contaminants in wastewater outflow.
Jim Meador is an aquatic toxicologist for the National Oceanic and Atmospheric Administration. In the summers of 2013 and 2014, Meador and his colleagues started collecting water and fish from the Puget Sound, he said. Analysis of the water taken from areas near wastewater treatment plants revealed a slew of chemicals and traces of drugs, including OxyContin, cocaine, Valium, Zoloft, ibuprofen, Metformin, birth control hormone and various antibiotics. Meador also found high levels of Prozac, amphetamines, antidepressants and other drugs in the tissue of juvenile Chinook salmon tested in the Puyallup River estuary, which is fed in part by the outflow of Tacoma’s Central Wastewater Treatment Plant.
Outflow from wastewater treatment plants in the Puget Sound Region contained higher levels of pharmaceuticals than outflow measured from the 50 largest treatment plants in the United States, according to Meador’s study. Local wastewater treatment plants could discharge up to 44,000 kilograms of dissolved drugs annually, according the study. Over 80 drugs and personal care products were found in the outflow of sewage treatment plants flowing into the Sound.
Scientists only started looking into the effects of human drug use on the aquatic environment about 15 years ago, said Mark Henderson, a water quality specialist for the Washington State Department of Ecology.
Amid the hiss of machinery at the city of Bellingham’s Post Point Wastewater Treatment Plant, the peaceful sounds of Bach echo throughout the lobby — opposite of what you might expect from a place that often uses the term “sludge.” Wastewater treatment plants can remove many contaminants and solids from the water, but most aren’t designed to remove pharmaceuticals.
“We don’t specifically filter out pharmaceuticals,” said Eric Johnston, assistant director of operations at the plant. “But we do have a program in the city to try to give people an opportunity to properly dispose of their pharmaceuticals.”
Most pharmaceuticals don’t enter wastewater as distinct solids. Instead, they’re often dissolved in urine, so typical treatments can’t always filter them out. Henderson said he thinks a better approach would be to figure out how to break down all the pharmaceuticals during the treatment process, rather than try to filter them.
Ecology regulates wastewater treatment plants, tracking acidity, biological oxygen demand and metals coming out of the plants. But the department doesn’t monitor pharmaceuticals in the wastewater, Meador said.
The human body does not completely metabolize all the compounds, so pharmaceuticals end up in the wastewater. Pharmaceuticals can also wash off of the human body or people can improperly discard them in toilets, sinks or trash. Drugs used for livestock, pets or aquaculture can also make it into the environment.
It’s difficult to reduce the chemicals entering the waterways, Meador said.
“There are millions of gallons per day going into these plants,” he said. “You just can’t put a filter on it and take it out.”
Few studies exist on the effects the current concentrations of these chemicals have on the environment, said Robert Daguillard, a spokesperson for the Environmental Protection Agency, in an email. Pharmaceutical concentrations in wastewater pose little risk to human health, Daguillard said. However, fish might not be so safe. Fish breathe and drink water, exposing them to more water than humans, Daguillard said.
Scientists haven’t tested the impacts of these drugs on most aquatic species, so they have to extrapolate from the effects on other species. These estimates suggest a low risk, but little data exists on the potential toxicity of these drugs to fish, he said.
Wastewater can be like a fingerprint of the drug-use patterns in each city. For example, wastewater from Bremerton contained higher levels of caffeine and birth control hormone than the water near Tacoma. Scientists and law enforcement agencies have even sampled wastewater to identify drug-use patterns in cities, Henderson said.
“Police departments in bigger cities are using chemical tracking for illegal drugs to track down in which neighborhoods they are more prolific,” Henderson said.
Drugs might have a life beyond the flush. Improving wastewater treatment will be a slow process, Meador said, but he’d like to see it happen.
“We are trying to help the ecosystem and keep things as pristine as possible,” he said.