Pennsylvania roads are being coated in radioactive wastewater − here’s why
Skip to content
Brine, a mixture of salt and water, is sprayed onto roads to prevent snow and ice from sticking or freezing to the pavement.<br>Portland Press Herald Collection via Getty Images
https://theconversation.com/pennsylvania-roads-are-being-coated-in-radioactive-wastewater-heres-why-286208
https://theconversation.com/pennsylvania-roads-are-being-coated-in-radioactive-wastewater-heres-why-286208
Link copied
Share article
Share article
Kopier Link
Blauer Himmel
Messenger
X (Twitter)
Print article
Pennsylvania’s roughly 100,000 oil and gas wells produce wastewater that’s many times saltier than seawater and contains radium, a known carcinogen. For decades, that saltwater, called brine, was spread on dirt and gravel roads across the state to control dust and also on paved roads to melt ice.
The state Department of Environmental Protection halted the practice in 2018, but residents continue to report oil and gas brine being spread in their communities. Now, a permit issued by the Department of Environmental Protection in May 2026 could open a new path for oil and gas well wastewater to be sold as a commercial product that could be purchased by road maintenance operators or snow removal businesses.
William Burgos and Nathaniel Warner, professors of environmental engineering at Penn State, have spent years testing whether oil and gas brine actually works as a road dust suppressant. Road dust is an issue because fine particles generated from traffic can get into residents’ lungs and cause respiratory issues, and the dust also reduces visibility, which can lead to accidents. Burgos and Warner spoke with The Conversation U.S.’s Pittsburgh Editor Cassandra Stone about what’s in the brine, why it fails at the job it’s supposed to do and what the new permit means for Pennsylvanians.
What is oil and gas brine, and why is it being spread on Pennsylvania roads in the first place?
Oil and gas wells produce a significant amount of water, called produced water or brine, along with the oil and gas they recover. In northwestern Pennsylvania, the ratio is around eight barrels of water per barrel of oil. The water is very salty – often five to 10 times as salty as seawater. It is generated from both conventional oil and gas wells and unconventional, or “fracked,” gas wells – such as those used to extract natural gas from the Marcellus and Utica shales in Pennsylvania.
The Pennsylvania Department of Environmental Protection banned using brine from fracked gas wells for dust suppression or anti-icing in 2016, and issued a moratorium halting the road spreading of conventional oil and gas brine in 2018. Well operators had previously provided the brine to local townships for free.
Before 2018, brine from conventional wells was spread on roads to prevent ice from forming.<br>Anadolu/Andolu collection via Getty Images
What’s in this water, and what do we know about its health and environmental risks?
Lots of calcium, sodium and chloride, but also radium – a radioactive element and known human carcinogen – as well as petroleum hydrocarbons and lead.
Most of these contaminants wash off the road and end up in streams and sediments. The salt can harm fish and other wildlife, and corrode bridges and automobiles. Salt from roads can also enter nearby drinking water wells.
Why are conventional and fracked well brine treated differently?
Geochemically, there is no obvious reason. Brines from conventional and unconventional wells are chemically very similar: Both are extremely salty and radioactive, and both contain heavy metals and organic contaminants.
For example, in Pennsylvania, the combined activity of two radioactive forms of radium averaged 2,000 picocuries per liter in conventional oil and gas brine and 1,800 picocuries per liter in unconventional Marcellus Shale brine.
There are numerous federal regulations from different agencies around discharges of radium to the environment, but many do not directly apply to oil and gas wastes. The EPA tries to follow the principle that radioactivity exposure should be “as low as reasonably achievable,” also known as ALARA. Their drinking water standard for combined radium activity is 5 picocuries per liter.
Obviously people are not drinking the oil and gas brine directly, but the problem is that we don’t know where the radium ends up after the brine has been applied to the road. It mostly washes off with runoff, but radium dried to the road could be remobilized as dust that someone inhales, or radium could accumulate in game fish eaten by fishermen.
Operationally, unconventional gas wells produce much more water than conventional oil wells, which may be the reason for the additional restrictions on disposal options. And historically, the two industries emerged under very different rules. Environmental regulations were already in place in 2008 when the...