PFAS may be contaminating drinking water for up to 70% of about 140 million people in the US who draw water from the nation’s aquifers via private or public wells, a new federal government study estimates. The findings show a potential impact on about 95 million people, or 27% of the nation’s population.
The US Geological Survey sampling and modeling of groundwater contamination found readings up to 37,000 times higher than the EPA’s new drinking water limits. In some regions virtually all of those using public systems that draw from groundwater may be drinking contaminated water.
This is especially a problem for those who draw from private wells, or small public wells, because neither is covered by strong new PFAS limits implemented by the Environmental Protection Agency – those people represent about 13% of the US population.
“This study’s findings indicate widespread PFAS contamination in groundwater that is used for public and private drinking water supplies in the US,” said Andrea Tokranov, a USGS hydrologist and the study’s lead author, said in a statement.
PFAS are a class of about 15,000 chemicals often used to make products resistant to water, stains and heat. They are called “forever chemicals” because they do not naturally break down and are linked to cancer, liver problems, thyroid issues, birth defects, kidney disease, decreased immunity and other serious diseases. As many as 200 million people were in recent years drinking PFAS contaminated water, according to some estimates.
The new study built on previous USGS research that took over 1,200 drinking water samples nationwide, as well as modeling. The aim is to help the government identify where there’s more potential for PFAS contamination.
It looked at several dozen of the most common types of PFAS, but thousands exist, so levels could be higher and more groundwater could be contaminated than estimated. However, some water utilities have begun implementing technology that removes PFAS, so the number of people who are drinking contaminated water could be lower.
The highest levels of exposure to potentially contaminated water in private wells were found in Michigan, Florida, North Carolina, Pennsylvania, New York and Ohio.
Meanwhile, California and Florida show the highest population levels potentially exposed to PFAS in water drawn from public wells. Up to 98% and 87% of populations in Massachusetts and Connecticut, respectively, who draw from public wells may have contaminated water.
The research found the usual suspects were behind the most polluted areas – military bases, airports, chemical production centers, plating facilities, plastic production and other industries.
Groundwater sources in areas with higher population density and more industry were more likely to be contaminated.
Depth also plays a role – deeper wells are typically safer because they are further from the pollution source, and public wells using groundwater are usually deeper than private wells.
Though wells near Memphis, Tennessee, are in an urbanized area, the region’s deep, old water aquifer is largely clean, while nearly every well tested that relies on shallow aquifers in the Ohio valley or New England regions had some PFAS in it.
The USGS also produced an interactive map that shows where there may be trouble.
