Every one of 91 private water wells and springs sampled across two southwestern Pennsylvania counties came back within the Environmental Protection Agency's legal limit for radium. That is the first thing residents in Washington and Greene counties should know about a new Penn State study.
The second is more complicated. Researchers found that six of the 91 samples could potentially be associated with fracking wastewater, and that samples taken within about two miles of unconventional oil and gas operations were more likely to show elevated radium, though not by a margin the team considered strong enough to call a broad correlation.
The study, published in Environmental Science and Technology, tests a two-step chemical pathway rather than a direct one. That structure is the whole story, and collapsing it produces a claim the data does not support.
Two Steps, Not One
Radium occurs naturally in soil and rock everywhere at low concentrations. The concern is not its presence but its mobility.
The proposed mechanism runs through salt. When salinity in groundwater rises, dissolved ions can displace radium that is otherwise bound to the surrounding rock, releasing it and other heavy metals into the water people drink. Elevated salinity does not create radium. It frees what is already there.
Nathaniel Warner, an associate professor of environmental engineering at Penn State, explained why that matters biologically. Because radium behaves chemically like calcium, the body routes it toward bone. Over time, he said in a university statement, "that radium will decay, releasing particles and energy that will damage your cells." Drinking water with elevated radium levels is associated with an increased risk of cancer, which is why the EPA regulates it under its radionuclides rule.
Earlier Penn State work had identified hotspots of elevated salinity near unconventional operations in the Northern Appalachian Basin. What was missing was radium measurement. Prior studies had tracked deep brine salts, such as sodium, chloride, barium, and strontium, in spill-affected areas without measuring radioactivity.
The Qualification the Researchers Insist On
Warner's own framing runs counter to a simple reading. Radium levels tend to rise where salinity is higher, he said, but that salinity can come from a host of other factors, including road salt, nearby septic tanks and even animal waste.
That is not a footnote. It means the study cannot attribute elevated salinity, and therefore elevated radium, specifically to drilling in most of the samples where it was observed. The team recorded higher salt concentrations near extraction sites, consistent with a drilling contribution. It is also consistent with several other explanations that the study design cannot exclude.
The six samples potentially associated with fracking wastewater are the narrower and firmer finding. The researchers interpret them as evidence that spills or mismanagement could produce localized effects, rather than that operations broadly contaminate groundwater. The proximity association within about two miles was present but, in the researchers' assessment, not significant enough to cite as a broad correlation.
The sample is 91 wells in two counties; homeowners participated voluntarily, and samples were taken at a single point in time before any household treatment system. Groundwater chemistry varies seasonally and by depth.
Households That Carry the Testing Burden
The regulatory context is what turns this from a research finding into a household one.
Pennsylvania does not regulate private water wells. Public water systems must test for radium and comply with the federal limit, and their results are published in annual reports. Private well owners have no such requirement or reporting. Testing, interpreting, and treating are entirely the homeowner's responsibility and expense.
That gap falls unevenly. Rural households in the counties with the most drilling activity are also the households most likely to be on private wells, and least likely to have a nearby public system to switch to.
Researchers described the community relationship as central to the work. "Communities want to know what is in their drinking water," said Jennifer Baka, an associate professor of geography at Penn State, who said the team spent years building relationships with residents living near these operations. Participants received their own water quality results.
The research was supported by the Health Effects Institute and the US National Science Foundation.
Reasonable Steps for Private Well Owners
Nothing in this study calls for anyone to stop drinking their well water. All samples were within federal limits.
The appropriate response is testing, which most private well owners have never done for radioactivity. Radium is not part of a standard well water panel. It must be requested specifically, along with radon and gross alpha, and the test should be performed by a state-certified laboratory. Pennsylvania's Department of Environmental Protection and Penn State Extension both publish guidance on testing and treatment for private well owners.
A practical shortcut exists. Because radium tracks with salinity, a basic test for chloride, sodium, and total dissolved solids is inexpensive and can indicate whether a fuller radioactivity panel is warranted. Households noticing a change in taste, a salty quality, or staining should test rather than assume.
Treatment is available where results warrant it. Ion exchange and reverse osmosis systems reduce radium, and the choice depends on water chemistry and the specific isotopes present, a conversation best left to a certified water treatment professional rather than a hardware store.
Households near active or abandoned wells who suspect a spill can report concerns to the state environmental agency, which investigates private water supply complaints.
The Penn State team plans to continue with larger samples and more targeted sampling near oil wells, and to extend the work to abandoned oil and gas wells across the region to assess how historical drilling affects communities today.
Key Questions Answered
Did the study find unsafe radium in drinking water? No. All radium levels in the 91 sampled private wells and springs remained within the Environmental Protection Agency's legal limits.
What did it find then? Higher salt concentrations closer to extraction sites, elevated radium associated with some drilling operations, and six of 91 samples that could potentially be linked to fracking wastewater. The researchers say the proximity association was not strong enough to warrant calling it a broad correlation.
Why does salt matter for radium? Rising salinity can displace radium already bound to surrounding rock, releasing it into groundwater. The salinity does not create radium; it mobilizes it.
Does this prove fracking is contaminating drinking water? No. The lead researcher noted that road salt, septic tanks, and animal waste can all raise salinity, and the study cannot separate those contributions from drilling in most samples.
Are private wells tested by anyone? Not in Pennsylvania. Private wells are unregulated, so testing, interpretation, and treatment fall entirely to the homeowner. Public water systems must test for radium and report results.
How should a well owner test for this? Request radium, radon, and gross alpha specifically from a state-certified laboratory, since they are not in a standard panel. A cheaper test for chloride, sodium, and total dissolved solids can indicate whether the fuller panel is warranted.
What if levels come back high? Ion-exchange and reverse-osmosis systems can reduce radium levels. The right choice depends on water chemistry and isotopes, so consult a certified water treatment professional rather than buying a system off the shelf.
