Despite firm opposition from the Havasupai Tribe, Arizona regulators on July 6 permitted a higher level of arsenic in groundwater under a uranium mine near the tribe’s place of emergence.
Before the approval, two groundwater scientists submitted comments urging the state Department of Environmental Quality (ADEQ) to require the owner of the Pinyon Plain uranium mine to give more proof that the higher levels were naturally occurring and not due to mining discharge or activities.
Energy Fuels Resources, the mine owner, says its investigation was thorough and that operators aren’t at fault. It also disputed those scientists’ findings.
A press release attributed to the Havasupai Tribe condemned ADEQ’s decision to issue the company a permit, and said it represents “a profound attack on the Tribe’s inherent responsibility to guard and protect the waters of the Grand Canyon.”
Tribal Chairwoman Melinda Yaiva said that ADEQ “made a choice” not to stand with the tribe and the people of Arizona.
“Instead, it chose to lower the bar for pollution and weaken environmental protections,” said Yaiva. “That decision does not simply affect the Havasu ‘Baaja—it affects every Arizonan who depends on clean groundwater today and every child who will depend on it in the future. We cannot replace a contaminated aquifer.”
KNAU first reported on Energy Fuels’ request for higher arsenic levels in the groundwater monitoring well in May.
Since then, U.S. Rep. Adelita Grijalva (D-Arizona) wrote a letter to the head of the ADEQ that she was “deeply concerned” about Energy Fuels’ request.
“As I understand it, additional studies and analyses help determine whether the elevated arsenic levels are naturally occurring or the result of mining activity has not yet been completed,” Grijalva’s June letter states. “Therefore, the company’s claim that these increases are naturally occurring remains unverified.”
The Pinyon Plain Mine sits near the South Rim of the Grand Canyon and Red Butte, a geographical feature the Havasupai Tribe considers their place of emergence.
An aquifer thousands of feet underground serves as the tribe’s only source of drinking water.
The approved amendment to groundwater well MW-02 raises the permitted concentration of arsenic from .050 milligrams per liter to .055 milligrams per liter and a related alert level from .040 to .050 milligrams per liter.
In a May interview with KNAU, Curtis Moore, Energy Fuels’ senior vice president of marketing and corporate development, said the presence of arsenic in groundwater is a byproduct of the mine’s proximity to minerals like uranium, arsenic and copper.
“It's not surprising that there are elevated levels of arsenic next to this ore body,” Moore said at the time. “That's why we put a mine there, because there's an ore body there. But, you know, there's really no evidence that demonstrates that arsenic is leaving the site. In fact, it's coming into the mine.”
In its decision to grant the permit, ADEQ agreed with Moore that the higher levels are naturally occurring.
The agency wrote that the data Energy Fuels provided it “confirm [n]aturally occurring arsenic from geology surrounding and outside the facility is moving toward the facility’s perimeter wells due to a hydraulic sink created by the mineshaft.”
Despite the decision, the Havasupai Tribe wrote in its press release that the fight over the Pinyon Plain Mine is not over.
“The Havasu ‘Baaja will continue to pursue every available legal, administrative, and public avenue to protect the Grand Canyon, our sacred homeland, and the waters that sustain life,” the release says.
