An environmental nonprofit on Tuesday released a new analysis of monitoring wells in the Grand Canyon region. The nonprofit Grand Canyon Trust says it shows wells within a nearby uranium mine have unusually high arsenic levels when compared to other groundwater sources in the area.
The group said the analysis of 40 wells throughout the region used 32 years of monitoring data, which it compiled by looking at well and spring sites listed in the U.S. Geological Survey’s water quality database.
The analysis also drew from print records from the Arizona Department of Environmental Quality, or ADEQ.
It found that four wells had average arsenic levels higher than the U.S. Environmental Protection Agency’s safe drinking water limit. One well sits on the Kaibab Plateau north of the Grand Canyon.
The other three, the nonprofit said, are located within the Pinyon Plain uranium mine. The mine is about nine miles from the South Rim of the canyon.
Havasupai Tribal Chairwoman Melinda Yaiva said the higher levels under the Pinyon Plain Mine threaten her community at the bottom of the canyon.
“If Havasu Creek is contaminated, there is no backup water system waiting for us,” said Yaiva. “The consequences would be immediate and profound.”
But not everyone agrees with the analysis, or that the tribe is at risk of harm.
Misael Cabrera is the senior vice president of environment, safety and sustainability at Energy Fuels Resources, the company that owns the mine. He argued the analysis takes data out of context, and reiterated an argument the company has frequently made that the increase in arsenic is not due to the mine.
Cabrera added that there’s no proof of connectivity between the aquifer underneath the mine and the aquifer the tribe relies on — though some scientists say that’s not true, and that there is some evidence of connection.
“[The analysis is] not providing sufficient context,” said Cabrera, who’s also a former official at ADEQ. “You will always have higher mineralization in the groundwater in areas where you have mines. Why? Because the geology is richer in minerals.”
Cabrera claimed that higher arsenic levels under the mine are caused by a cone of depression, which is drawing naturally high arsenic levels toward the mine shaft. The Pinyon Plain Mine is located near a breccia pipe, a mineral formation that includes elements like arsenic, copper and uranium.
Energy Fuels’ argument is one that state regulators at the department of environmental quality recently agreed with.
In July, the agency permitted a higher level of arsenic in groundwater despite objections from two scientists, the Havasupai Tribe and Grand Canyon Trust. That permitting decision was subsequently upheld on appeal, because a state water quality board determined the tribe’s challenge lacked standing.
Some scientists say Energy Fuels’ explanation that the higher arsenic levels are due to natural phenomena is a hypothesis, not a proven fact.
That includes Brad Esser, formerly of Lawrence Livermore National Laboratory, Dave Kreamer, emeritus professor at the University of Nevada, Las Vegas, and Laura Crossey, emerita professor at the University of New Mexico.
In a press conference hosted by the Grand Canyon Trust, the three scientists argued it’s not true that the Coconino aquifer, which sits under the mine, and the lower Redwall-Muav aquifer, which the Havasupai Tribe depends on for its sole municipal water source, are unconnected.
The scientists contend the tribe is at risk of elevated arsenic levels in the upper aquifer, and that Energy Fuels has not explored enough alternative explanations for the higher levels.
“We know from the spring chemistry emerging from the [Redwall-Muav] aquifer that we have recently recharged water,” Crossey told reporters. “We have things like the [synthetic human-made compounds] … even in the deep well, so that right there tells you directly that there is some connection.”
But Cabrera insisted that there’s no proof the two aquifers are connected.
“All of the evidence that's been produced across decades of study and court cases suggests that there is no communication between those aquifers,” he said.
KNAU asked Cabrera a question posed by scientist Kreamer at the press conference: If arsenic concentrations in groundwater outside the mine are lower than inside, how can drawing low concentrations from outside increase the already high concentrations within the property?
In asking that question, Kreamer referenced data from a USGS well outside the property that he said has lower arsenic levels than within the mine.
Cabrera said there’s a contextual problem with the idea underpinning that question.
“In a mine, you have highly mineralized areas, but those mineralized areas are not uniform, so what we see as we're mining is that the highest mineralization occurs for us towards the northern end,” he responded. “The well he's talking about is not in the same area.”
“Researchers are good at asking questions and developing hypotheses. I do not fault them for that,” Cabrera continued. “However, there is no evidence, none, that our mining operations are causing increased arsenic concentrations.”
KNAU also asked Cabrera how he responds to the possibility that no amount of uranium mining near the Grand Canyon, no matter how safe, will satisfy the Havasupai Tribe, which has opposed the mine since 1986.
“Given the history of tribal relations in our country, I would never diminish the Havasupai or any other tribe's concern,” he said. “But what I would respond with is that all of the regulatory, but also scientific evidence suggests that there is no reasonable possibility that they will be impacted.”
For Chairwoman Yaiva, the issue at hand is one of existential importance.
“If people can no longer trust the safety of our water, the damage would extend far beyond an environmental problem,” she said. “It would threaten the health, culture, economy and future of the Havasupai people. This is why this is also an issue of sovereignty.”
Disclosure: Grand Canyon Trust is a financial supporter of KNAU.
