About 800,000 Oregonians might rely on private or public well water contaminated by toxic chemicals called “forever chemicals,” or PFAS, according to a federal study.
Researchers with the U.S. Geological Survey analyzed over 1,200 untreated groundwater samples across the country, then used those results to predict how surrounding regions may be impacted. They published their results in late October.
Compared to other states, Oregon ranks 25th for the number of people using water from public or private wells that are possibly contaminated with PFAS. Washington ranks 9th, with an estimated 3.1 million people using potentially contaminated groundwater.
Researchers published an interactive map showing where the most people may be impacted. Oregon shows concentrations of affected water users along the Interstate 5 corridor, where more people live.
Nationally, more than half of people in the lower 48 states drink water that could contain traces of PFAS.
“That’s a pretty striking number that I don’t think they expected going in,” said lead author and USGS research hydrologist Andrea Tokranov.
FILE: Well water runs from a faucet in a residential home near in Crook County, Oregon. June 9, 2024.
Emily Cureton Cook / OPB
PFAS are man-made chemicals that don’t break down, giving them the name “forever chemicals.” They accumulate in people’s blood over time, increasing people’s risk for cancer, high blood pressure and other harmful health effects that scientists are still studying.
Consumer product chemists created PFAS in the 1940s. The chemicals are often used as a surface coating due to their unique ability to repel oil, grease and water. Lagging environmental regulations over the last eight decades have allowed these toxins to make their way into a dizzying array of consumer products, including makeup, waterproof clothing and non-stick cookware.
A long list of polluters can contaminate surrounding water sources with PFAS. The four major sources are firefighter training sites, industrial sites, landfills and wastewater treatment plants or their resulting sewage, called biosolids. The chemicals can travel through waterways or rain clouds. They seep into the ground, infiltrating aquifers — layers of rock and sand saturated in water — that public and private wells tap into.
This study doesn’t look in detail at specific cities or zip codes, and it doesn’t provide information about how much PFAS may be in these groundwater sources. Still, Tokranov said, it can help groundwater users see if they’re in a high-risk area.
“We especially think it’s useful for private well owners who might not have a lot of information on their water quality,” Tokranov said.
This model could also serve as a guide for public groundwater suppliers, who will have to start testing for — and mitigating — PFAS by 2029. PFAS treatment systems can cost tens of millions of dollars.
Vancouver is among those public groundwater suppliers. The city gets its water entirely from wells tapping into three underground aquifers, and much of that water has PFAS levels exceeding new federal regulations. Vancouver officials say they’re on track to build a series of filters by 2029.