Drinking Water In America Is Often Contaminated

The study also found that those living on tribal lands or in minority communities may be disproportionately affected by water contamination, and predicted that it is possible that climate change could make it harder to locate safe sources of drinking water in the future. 

“There were several of us that have expertise in dealing with these particular contaminants, and we were seeing that they’re not always at safe levels in drinking water sources for a number of reasons,” said Johnnye Lewis, Ph.D., professor emerita in the Department of Pharmaceutical Sciences, multiple principal investigator of the Navajo Birth Cohort Study, co-director of Community Environmental Health Program and director of the UNM METALS Superfund Research Program.

The study assessed 7 known contaminants that most often find their way into drinking water: lead, nitrates, arsenic, fracking fluids, uranium, PFAS, and chlorinated disinfection byproducts. Most of these substances are suspected carcinogens, and exposure to most of these has been linked to a host of other issues such as developmental and neurological problems. The researchers found that the ability to detect and remove these substances from drinking water varied widely. 

“Some of these, like uranium and arsenic – and even nitrates – are just common,” Lewis said. “They commonly occur in groundwater, and sometimes it is the source that you have access to.”

Some contaminants are introduced by humans and represent uncharted risks, others can linger in the environment for decades without degrading. These 7 only represent a small fraction of thousands of chemical agents present in water, according to the researchers. To make this matter worse, two or more contaminants may be present in a water source at the same time which could have synergistic effects.

“I think there was concern, but it wasn’t at this scale and was elevated to where it is now,” she said. “It’s like much of what we do as a society. You take the action first and then down the road try to figure out how to fix it. That’s usually a bad strategy.”

“We’re only really now starting to come up with good methods to assess what those mixtures do,” Lewis said. “There’s always a lot of uncertainty, because a mixture is not the same in one community as it is in the next.”

Newer and larger water systems have the ability to remove or dilute the concentrations of some contaminants, but many Americans lack even the most minimal protection. There are an estimated 150,000 public water systems in the U.S., around one-third of them are community water systems serving about 320 million people (95% of the population). 91% of the community water systems serve fewer than 10,000 people, covering 52 million in all, and over 43 million people rely on private wells for drinking water. 

The researchers say that their study “highlights the need for a concerted effort to invest in upgrading our drinking water infrastructure, strengthen drinking water standards, develop and implement enhanced water treatment, collect and disseminate monitoring data, and require more stringent chemical safety testing.”

“For me, the thing that is most concerning is that you start looking at drought and the stresses that that puts on looking for additional water sources,” she said. “The potential for making sure those sources are clean could become more limited.”