EPA transfers carbon injection well oversight to Arizona amid growing safety concerns

Arizona will have total control over regulation of underground wells to store carbon captured from industrial facilities, the Environmental Protection Agency announced Thursday, even as environmental groups have been urging the EPA to halt approvals of the wells. 

Underground injection wells, often referred to as carbon injection wells, are viewed by some as a way to store carbon dioxide in the earth — but in liquid form instead of the gas that is a driving force behind climate change. 

However, the largely untested technology hasn’t been deployed without its problems, including one pipeline rupture that caused evacuations and leaks at wells in Illinois that have raised concerns over possible future water contamination.  

And carbon dioxide wells in Texas are expected to cause more earthquakes, blowouts and other geological issues. 

Arizona Republicans and Gov. Katie Hobbs applauded the decision to give the power to regulate the wells back to the state. 

“Arizona has long prioritized securing authority over underground injection wells, and I’m encouraged to see the EPA take this important step forward,” Hobbs said in a statement. “Giving the state direct oversight is critical to protecting the integrity of our groundwater resources while supporting responsible economic growth and clean energy development. This decision strengthens Arizona’s ability to manage our future and gives us the tools to lead on sustainable resource management and innovation.”

The Arizona Department of Environmental Quality, the state agency that will be responsible for implementing the proposed changes, submitted a formal application to the EPA in February of 2024 seeking to obtain the ability to directly regulate injection wells. 

“We remain committed to advancing state-led protection of Arizona’s groundwater and drinking water resources,” ADEQ Water Quality Division Director Trevor Baggiore said to the Arizona Mirror. “Once granted primacy, ADEQ will be responsible for administering the program in Arizona. This will enable the state to directly regulate Class I, II, III, IV, V, and VI injection wells with oversight tailored to Arizona’s unique hydrogeologic conditions and water protection priorities.”

At a press conference in Washington, D.C., EPA Administrator Lee Zeldin was joined by Arizona GOP Congressmen Andy Biggs, Juan Ciscomani and Paul Gosar Thursday morning to make the announcement. All three applauded the decision, thanking the Trump administration for allowing Arizona to permit the wells. 

“This new policy is going to benefit Arizona, and we couldn’t be happier,” Ciscomani said, adding that Trump’s EPA is keeping its promises of “cutting the red tape.” 

“This is a tremendous benefit and blessing,” Biggs said. “I’ve never been able to say ‘my friends at EPA,’ but I can now.”

Environmental groups have been voicing concern over underground injection wells — and even suing over their regulation. In West Virginia, a state that was given similar authority recently by the EPA, a lawsuit was filed that argues the state will not have adequate funding to maintain proper oversight of the wells. 

That concern is shared by some in Arizona, as well.

“We are especially concerned about the lax oversight with today’s EPA, which has been almost weekly promoting weakening of protections,” Sandy Bahr, Chapter Director for the Grand Canyon Chapter of the Sierra Club, told the Mirror. “There is also concern about the lack of staff at the EPA and the additional proposed cuts that are under consideration. Our drinking water is just too important.”

Bahr said they are concerned that the Arizona Department of Environmental Quality does not have the adequate funding to do proper oversight. 

“(ADEQ) should absolutely say no to these carbon storage injection wells and for other injection wells,” Bahr said. “They should take a good hard look at them and implement the most protective standards possible to ensure protection of our groundwater.” 

There are no carbon injection facilities in Arizona and no permits have yet been requested to build any in the state. 

“Any carbon injection facility would have to meet the (Underground Injection Control) program requirements, which includes demonstrating that Arizona’s underground sources of drinking water are protected,” Baggiore said.

While much of the metro Phoenix and Tucson regions receive most — if not all — of their water from the Colorado River, the same isn’t true in most of the state, where water comes from underground aquifers.

“It’s not a question of whether these things are going to leak,” Abel Russ, an attorney with the Environmental Integrity Project, a watchdog organization based in Washington, D.C, told the Louisiana Illuminator last year. “It’s a question of how much is acceptable and how much is going to be happening.”

Although wells to store carbon dioxide have been a major focus, the change also opens up permitting for other types of injection wells. During the fracking process, wastewater is sometimes pumped into underground wells meant to keep the toxic water from contaminating the environment, though it sometimes still finds a way out. 

Environmental advocates and residents have raised concerns about the impacts of similar methods used for proposals such as helium fracking in the Navajo Nation and uranium mining in the Coconino Plateau that could both contaminate groundwater in a similar fashion. 

The EPA will hold a virtual public hearing on June 25, 2025 from 5 p.m. to 8 p.m. on the proposed change where the public can provide feedback.