Concerns voiced about Copper World mine's air emissions

A flood of issues were raised at a public meeting about a proposed air quality permit for a big copper mine in the Santa Rita Mountains.

Among them: The reliability of computer modeling, the quality of enforcement, the potential for fine particles to damage kids’ lungs, and concerns about lead and sulfur emissions and a sulfuric acid plant.

At the meeting Wednesday night, more than 20 speakers expressed wariness, fear, skepticism and cynicism about the Arizona Department of Environmental Quality’s ability and willingness to effectively monitor and police air emissions from the Copper World Mine. The meeting was held at Corona Foothills Middle School a few miles north of the Santa Ritas.

“I believe this mine is a mistake. One reason is its location, up at an elevation over a valley full of people,” said Charles Stack, an environmental consultant who said he’s worked with businesses including mining companies. “The median age in Green Valley is about 70 years. We have schools and a hospital. I used to teach at Walden Grove High School in Sahuarita.

“We have a vulnerable population,” said Stack. He said he moved from the Quail Creek development near Green Valley in 2022 to Oro Valley, where he now lives, once he realized the mine would operate on the Santa Ritas’ west slope facing Sahuarita and Green Valley.

Hudbay Minerals Inc. wants to build the mine on both sides of the Santa Ritas. It would dig six open pits large and small to extract copper ore, then refine it into copper concentrate and, starting a few years after it opens, process it into pure copper cathodes for sale to other users. The mine’s main processing facilities would lie about 30 miles southeast of Tucson on East Santa Rita Road.

Only one of 23 speakers had a positive outlook about ADEQ’s plans for regulating the mine.

ADEQ officials responded in great detail to residents’ comments and questions. They strongly defended the computer modeling used, which found that emissions levels from the mine wouldn’t lead to violations of federal air quality standards.

They promised to closely watchdog the mine site for possible violations of state and federal air quality standards. Among the ADEQ officials who came down for the meeting from agency headquarters in Phoenix was Daniel Czecholinksi, the agency’s air quality program director.

“We are going to have inspectors out there on a very regular basis. They know which areas are likely to be problematic and take a close look there,” said Balaji Vaidyanathan, ADEQ’s air permits and compliance manager. “Inspections are unannounced. We don’t let the company know when we are showing up.

“We will see them truly operate the way they normally do. (If) you should observe something or be concerned of environmental compliance issues, we have contacts, business cards and an inspection and hotline number you can call and report,” Vaidyanathan said.

The first resident to speak, John Paul Salvatierra, told ADEQ, “I understand modeling is modeling. It’s all company created. The reporting is done by the company. Who will the (permit) protect? The corporate reporting or the people that will be affected? If a permit is issued, shouldn’t it protect the public more in the long run?”

Replied Czecholinski, “The permit is protective of public health and the environment. It protects everyone. (The company) has to follow permit requirements. It’s a contract between ADEQ and the permittee.”

The air quality permit is one of two major state permits the mine needs. ADEQ has held a public meeting and a public hearing on the other, an Aquifer Protection Permit meant to insure the mine doesn’t pollute groundwater. A decision on that permit is due by the end of August, said ADEQ Communications Director Caroline Oppleman.

ADEQ’s draft air permit for the mine listed numerous sources of air emissions at Copper World. They include drilling, blasting, loading and hauling. Other sources are ore processing operations, which involve crushing, milling, flotation, concentrate and tailings filtration and management.

Emissions will also come from dust collectors, vehicles traveling on unpaved roads, wind erosion from tailings sites and stockpiles, loading/unloading of ore and waste rock, material transfer points, a solvent extraction plant, emergency generators, firewater pumps, and the sulfuric acid plant, ADEQ said.

But computer analysis carried out by a Hudbay consultant using a U.S. Environmental Protection Agency-preferred model found five pollutants generated by the mine will not boost the surrounding air to concentrations exceeding federal limits, ADEQ said. The pollutants are large and fine particles, nitrogen and sulfur dioxide and carbon monoxide.

Other questions, answers

Those findings didn’t assure many of the 100 or so residents attending the meeting. Some of their concerns included:

— Cathy McGrath, who lives near the mine site, told ADEQ the company’s permit application in 2022 was based on earlier plans, which included two facilities for storing mine tailings. Hudbay has since revised its plans to add a third tailings facility, she said, but that’s not covered by the current draft permit.

“Why is it not in the permit?” she asked ADEQ.

ADEQ’s Vaidyanathan answered that if Copper World is to operate a third tailings site, “They will need to come back to us and work with us. They will need another permitting evaluation. We need to figure out what the emissions will be. The permit limits them to only what they applied for.”

McGrath, saying she lives about 480 feet from the third tailings site, said her point is that by not having this site in the permit, it makes total emissions appear lower than they actually will be. An elementary school lies about 1.5 miles from the mine site and a subdivision is one mile away, she said.

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From a public health protection standpoint, “you have good reason to be concerned,” Vaidyanathan said, adding, “That will be addressed. They have to do modeling. They have to convince us ….”

— Peggy Ollerhead, a retired school psychologist, said that in a job she had in the early 1990s at a hospital affiliated with Johns Hopkins University, she did evaluations of lead poisoning impacts on children.

After seeing “devastating effects … I felt I had a moral obligation to come here and tell you that according to the Journal of the American Medical Association, there is no known safe level of exposure to lead for children,” she said.

“We know there is a school within one and a half miles from the proposed mine, and also housing units. Can’t we do some testing there for lead or does it all have to be within a certain perimeter of the mine? Can you set up a monitor near the school?” Ollerhead asked ADEQ.

ADEQ’s Czecholinski agreed there is no safe level of lead exposure for children, and that he’s not opposed to having a lead monitor at the mine site.

“Since I’ve been director of the air quality division, we’ve done air quality monitoring across the state. It’s something we’ll definitely consider. I think at this time, it’s premature to make that commitment,” he said.

(The National Academy of Sciences says, “Lead is a widespread, naturally occurring element found throughout the Earth’s crust. It occurs in virtually all rocks, soils, sediments, and waters at low concentration.” The Copper World Preliminary Feasibility Study and Preliminary Economic Analysis say that “somewhat elevated” lead levels were found in some concentrate solutions that were analyzed for testing.)

— Nancy Kowalski said that as a nurse practitioner in Southern Arizona for 17 years, “I’ve seen a lot of patients in the past with lung disease, cardiovascular disease and I know that small particles of 10 microns or less are implicated in worsening chronic diseases such as cardiovascular disease, heart failure, emphysema and asthma.”

She asked ADEQ why the modeling done for Hudbay’s air quality permit didn’t consider what she called “extreme high frequency wind events” of more than 45 miles an hour.

“What about wind gusts higher than 45 miles an hour? We frequently have them higher than that,” Kowalski said.

Defending the computer model used for projecting Copper World emissions, ADEQ’s Vaidyanathan said this and other computer models are inherently conservative and “designed to overestimate a little.”

“We assumed maximum modeled concentrations from the facility and maximum (natural) background concentrations happen at the same time. It’s a very aggressive, conservative assumption. In reality, it never works like that.

“We are overestimating and on top of that we’re assuming both things are happening the exact same day, the exact same time,” he said.

— The lone positive comment came from Bill Ruiz, of the Southwest Carpenters Local 1912. He said he had a question coming into the meeting about how the Copper World permit will allow environmental protection, “and you all answered my question.”

“Mitigation techniques will be well observed and monitored. The department has shown science and scientific methods were well written into the plan. I am very encouraged that working men and women who work there will have confidence to work safely there.

“You’re talking about chemicals and ores, and our union … we are trained by safety and health experts. We rely on engineers. We rely every day that nothing is going to collapse ….”

— Stack, the environmental consultant who lives in Oro Valley, said the mine’s sulfuric acid plant will be a dangerous facility.

“Sulfuric acid is very dangerous. They will produce yellow elemental sulfur as as a byproduct of chemical processing. They will then use that recovered sulfur to produce sulfuric acid on site, when most mines in Arizona bring it in by tanker.

“… You are 1,000 feet above mean sea level over Quail Creek. One feature of this valley is we get atmospheric inversions, so you are going to get a cap of warm air that keeps things down … Any type of an industrial accident, you will run the risk of having that flowing down the side of the mountain.”

ADEQ’s Vaidyanathan replied: “Our modeling, whether we think of it as perfect science or not, is the best tool out there. It takes altitude into account, wind speeds, and directions. The conclusion we came to is we believe the impacts off the plant at the fence line are going to be safe. They are going to have continuous monitoring.”

— Chris Werkhoven said a recent study found an association between emissions of fine particles such as those that would come from this mine and the incidence of Parkinson’s disease, even when the fine particle concentrations are at levels “way below the current (federal) standard.” The study of Medicare patients was published by the Barrow Neurological Institute in Phoenix.

“Are you willing to explain to doctors what the dangers are below the current standards?” Werkhoven asked ADEQ.

An ADEQ official said this information is very valuable, but noted that EPA sets the standard and the state agency only enforces it. It was recently lowered, “and this permit meets those limits. It’s unlawful for me to have a lower standard. I don’t have any mechanism to do that.”

Arizona state law forbids the state from enacting any environmental laws or rules stricter than federal laws or rules.