Senate lawmakers grilled the head of the EPA at hearing on Wednesday over last month's massive mine spill in southeast Colorado.
"This is a disaster on many levels to our water, to our economy, to our culture," said Sen. Tom Udall (D-NM).
"There's no denying they caused this spill and that was entirely unacceptable," said Sen. Michael Bennet (D-Colo).
"Affected communities and stakeholders deserve transparency and accountability in the events surrounding this spill particularly in understanding where the EPA was in the first hours and days following the spill," said Sen. Cory Gardner (R-Colo).
The Senate Environment and Public Works Committee hearing was the first time EPA Chief, Gina McCarthy answered questions about her agency's response to the spill.
McCarthy defended the EPA's actions, but took responsibility for the Aug. 5 spill. EPA workers accidentally unleashed 3 million gallons of mine waste into the Animas River.
"This was a tragic and unfortunate incident and EPA has taken responsibility to ensure that we clean it up appropriately," said McCarthy.
Republican lawmakers demanded answers about what happened, why affected communities weren't notified sooner and why the EPA wasn't prepared for a potential blowout.
"Both the EPA and the contractor knew that there was a risk of a blowout at the Gold King Mine. In hindsight do you agree that the EPA should have spent the time and money to do the necessary engineering and water pressure tests before work began there?" asked Chairman Jim Inhofe (R-Okla).
McCarthy disagreed, saying the state and Animas River stakeholders were aware of the plan and the EPA was actually at the Gold King Mine because of the risk of a blowout.
Sen. Dan Sullivan (R-Alaska) also slammed McCarthy for what he called a double standard.
He pointed out the EPA has criminally charged private companies for causing much smaller spills than the one at the Gold King Mine.
"If you think the EPA should be held to the same standards as a private sector or a higher standard, do you think anyone from the EPA should be held criminally liable or go to jail for what happened," asked Sen. Sullivan.
"I have not received the independent review that is going to fully tell me what happened at that site," responded McCarthy.
Democrats used the hearing to bring attention to a larger issue.
"EPA is not the only responsible party, what happened at the Gold King Mine is part of a much much bigger problem. Abandoned mines in the West are ticking time bomb," said Sen. Udall.
Cleanup at the Gold King Mine could end up costing taxpayers more than a billion dollars.