Hudbay will need more permit reviews for Copper World

Developers of the Copper World complex, where six open pits are planned south of Tucson, may soon get the state groundwater protection permit they need, but that won’t end conflict over the permit.

Two features of Hudbay Minerals’ Inc.’s proposed plan for protecting groundwater at its mine in the Santa Rita Mountains will need to go through a separate round of permitting, possibly with additional public comments and meetings, regardless of how the current round turns out.

That’s because these features were included in Hudbay’s 2023 preliminary feasibility study for Copper World, but not in the 2022 application Hudbay submitted to the Arizona Department of Environmental Quality for an Aquifer Protection Permit. Such a permit is needed for the mine to be built and to operate.

That’s the word from ADEQ in response to questions from the Arizona Daily Star.

The department’s action won’t go as far as mine opponents want. Led by the longtime opposition group Save the Scenic Santa Ritas, they want the entire permit rejected and a new permit required to cover those and two other changes they say are significant.

Simply put, the opponents’ view is, as they wrote in comments to ADEQ, “The mine proposed in the (permit) application is a placeholder only and is not the mine Hudbay intends to build.”

“The application process should be suspended until an accurate mine description, with accompanying technical analysis, is included in the application,” the group said. “There are significant changes to the mine as proposed in the application.”

A requirement for additional permitting for the mine will at least delay the end of the entire aquifer protection permitting process, and force Hudbay to undergo additional reviews before it can be sure of having the final state approval of the project.

Hudbay says it’s standard practice for mining companies to revise plans during the often prolonged permitting process. Its draft permit issued by ADEQ complies with all applicable regulations and standards under Arizona law, the company told the Star.

“As part of the standard permitting process, ADEQ will address and respond to questions arising from the public comment period and make any necessary adjustments to the permit accordingly,” Hudbay said.

“We will apply for amendments to the APP as necessary,” said Hudbay, referring to the Aquifer Protection Permit it may soon get. “Hudbay is committed to environmental responsibility, regulatory compliance, and continuous improvement.”

ADEQ said it will decide on the $1.3 billion mine project’s current permit application in August. It previously released a draft permit that says the mine’s current plan will prevent violations of groundwater quality standards from mine discharges.

“We have been carefully reviewing, considering, and responding to the comments received during the formal comment period. This is a critical step in the permitting process,” department spokeswoman Alma Suarez said Wednesday.

“We evaluate each of these comments and update the permit as appropriate. These comments and responses will be provided to all commenters in a document called a Responsiveness Summary that will be released with the final permitting decision in August.”

Fourteen opposition groups led by Save the Scenic Santa Ritas filed nearly 80 pages of written comments hoping to stop the permit from being issued or to force major changes.

Save the Scenic Santa Ritas spent what Rob Peters, the group’s director, said is a “substantial” sum of money — a figure the group didn’t disclose — to hire three outside consultants to review and critique the permit. They are hydrologists Laurel Lacher of Tucson and Ann Maest of Colorado and retired mining engineer David Chambers of Montana.

“The draft (aquifer) permit is extremely technical to the point that a normal person wouldn’t know whether what’s being proposed is a good thing or not a good thing,” Peters said.

For example, he noted that Hudbay and the aquifer permit propose to install a pipe drainage system under copper mine tailings to collect pollutants and other liquids that seep through them. The piping is supposed to collect 98% of the liquids.

“A lay person can’t possibly evaluate whether or not those pipes are going to keep people safe,” said Peters. The group’s experts have years of experience and know what standard mining practices are and whether what’s proposed is safe, he said.

Hudbay noted that its preliminary feasibility study is its most recent mining plan but not the final one.

“It is normal for project proponents to adjust and modify their plans throughout development but unless those changes are authorized by the applicable permits, they cannot be implemented,” the company said in response to questions from the Star.

“We would not begin a permit amendment until we know the final mine plan,” Hudbay said.

The two features of the mine that will definitely require separate permitting are a new facility for storing and disposing of Copper World’s mine tailings and a reconfiguration of an already planned tailings storage area. These tailings projects either weren’t included in the permit application Hudbay filed in 2022 with ADEQ or have been changed since then.

The changes were contained in a Copper World preliminary feasibility study that Hudbay released in September 2023.

If a permit is issued, “any design changes or modifications to the discharging facilities require the permittee to submit a permit amendment to ADEQ,” the department’s spokeswoman Suarez said.

In their written comments to the agency, opponents identified four changes, including those two, to the mine plan since the 2022 permit application was filed that they said warrant a new permitting review. The other changes include a much larger amount of waste rock for deposit at the mine site and a different process for leaching certain kinds of copper from ore.

“Instead of approving Hudbay’s plan piecemeal … ADEQ should require a new application that lets it assess how the entire mining project would affect water supplies. Now is the time for ADEQ to show that it will do its job of protecting the state’s citizens instead of bending to the will of the mining companies,” Peters said.

In response, Hudbay said its current permit proposal remains relevant, despite updates to the mining plan shown in its 2023 feasibility report.

A favorable decision on the aquifer permit, once all aspects of the mine project are approved, would clear one of two remaining major legal hurdles before Hudbay can start building its project. It also must obtain an air quality permit from ADEQ.

Hudbay also faces a pending lawsuit from mine opponents seeking to overturn the Arizona State Land Department’s governing board’s decision to allow a mine tailings pipeline to be built on a small slice of state land near the Copper World site. A defeat for Hudbay in that lawsuit wouldn’t stop the mine but it might force the company to seek permission from the federal government for a separate route for the pipeline across U.S. Bureau of Land Management land. That would require a much more detailed environmental review.

Details of the other two changes in the mine plan cited by opponents are:

— The original Hudbay aquifer permit application called for excavating and depositing about 477 million tons of waste rock in various places on the mine site. The destinations include a specific waste storage facility and several of the mine’s open pits. They would be backfilled with the waste rock once their ore bodies are exhausted.

Hudbay’s September 2023 preliminary feasibility study, however, ratcheted up the amount of waste rock to be stored and disposed of to about 856 million tons. That represents a nearly 80% boost in expected waste rock.

Back to homepage

Subscriber Login

Keep reading with a digital access subscription.

Subscribe now

— The same 2023 feasibility study called for replacing an earlier plan to use a heap leaching operation to extract copper with a different kind of process known as the Albion Process.

Heap leaching extracts copper from ore by pouring large amounts of acid onto one or more “heaps” of mineral ore, which themselves are typically placed atop an impermeable pad to prevent the acids from escaping.

The Albion Process involves injecting the copper ore with oxygen as well as acids as a way of removing the actual metal, inside tanks as opposed to on a leach pad.

The operation also involves grinding the ore into very fine particles. Hudbay said it chose that method because it’s been shown to have higher copper extracting rates than heap leaching.

Chambers, one of the three consultants hired by the opposition group, said he would expect the Albion Process would produce more “byproduct metals” and potentially more pollutants “because the acid-leaching process is more effective than in heap leaching. That is one reason we need to see test data on any solid and liquid wastes from the Albion Process.”

ADEQ didn’t respond to a question from the Star about whether the additional waste rock storage would need a permit amendment.

But ADEQ has flipped its stance on whether Albion needs additional permitting.

Originally, on June 28, ADEQ told the Star, if Copper World wants to incorporate the new and reconfigured tailings facilities into its mining plan, or to add the Albion Process, it would need to submit an application to amend its permit. That process would include a formal public comment period and a public hearing, Suarez said.

But late Friday, Suarez very strongly suggested without saying it outright that the Albion Process won’t need an additional permit or review.

First, she said, ADEQ erred in saying earlier that Albion wasn’t in the 2022 permit application: it was mentioned there, complete with an illustration.

Second, the state Aquifer Protection Permit program regulates discharging facilities, such as impoundment or a tailings site, not specific mineral processing methods, she said.

The concentrated leach process used in Albion “is completed in tanks, which are not regulated under the APP. The concentrated leach process does not add any discharging facilities to the mine,” Suarez said.

In its responses to questions, the mining company told the Star, “Hudbay’s current APP application incorporates both heap leaching and concentrate leaching processes, each designed to minimize environmental impact and comply with air and water quality standards.

“It is important to understand that the Albion Process is just one specific technology used within the broader concentrate leach process,” Hudbay said. “The wastes from concentrate leaching are already considered in the draft (permit). The additional detail of ‘Albion’ does not matter in this context.”

Here are details of three other major issues raised by Save the Scenic Santa Ritas’ consultants in written comments to ADEQ about the proposed Copper World aquifer permit; Hudbay’s responses follow in each case.

1. NO DISCHARGE LIMITS AT FIRST. Consultants for the mine opponents challenge ADEQ’s approach that would allow mine construction to begin before it establishes formal limits on what Copper World can discharge into the aquifer. They argue that baseline monitoring and establishment of permit limits should happen first.

Consultant Lacher noted that the draft Aquifer Protection Permit doesn’t require Hudbay to propose formal discharge limits of pollutants from the mine until after it conducts eight rounds of quarterly groundwater sampling at the site.

“Construction of the mine, which will result in contaminant releases, is allowed to begin before the baseline monitoring is completed. This gap in coverage allows for groundwater contamination without regulation and biases the results of baseline monitoring,” consultant Maest wrote.

Responding, Hudbay said, “Our approach to the Copper World project adheres to standard practices across the state and ensures that construction will not release contaminants to groundwater.”

It will establish discharge limits before it actually operates any mine facilities specifically covered by the Aquifer Protection Permit, such as process water ponds and tailings, the company said.

“Hudbay is dedicated to safeguarding Arizona’s precious water resources,” the company said.

2. ADEQUACY OF WELL NETWORK. Opponents say the monitoring network of 10 wells that ADEQ proposes to check whether the mine contaminates groundwater is inadequate. The wells are planned to be installed on the various Copper World facility boundaries.

This is especially the case because of Hudbay’s plans to add a second tailings storage and disposal site and to more than double its waste rock production, opponents said.

Additional monitoring wells should be placed between the mine’s western facilities and the Santa Cruz River, and between the easternmost planned open pit on the old Rosemont Mine site and Davidson Canyon to the east, Lacher said.

At issue are what ADEQ calls “point of compliance” wells. They are points set by the aquifer permit where groundwater monitoring is required to establish whether the mine complies with state water quality limits.

In response, Hudbay said it is “currently reviewing concerns raised during the public comment period” about point of compliance wells.

“This includes comments regarding the number and location of the proposed POC monitoring wells,” Hudbay said.

Under Arizona law, such wells need to be located within 750 feet of the discharging facility in order to detect any groundwater issues quickly so that they can be addressed, Hudbay added.

Responding to Hudbay’s comment, the opponents said because multiple aquifers lie downstream of the mine site, the connection between aquifers under the mine site and those in every direction downstream “must be explicitly identified to ensure that early detection is optimized.”

3. TAILINGS DAM FAILURE ISSUES. Chambers said the computer model Hudbay used to project the possibility of a tailings dam failure assumes only 1% of the tailings would be released if one occurred. The amount of tailings assumed to be released should be between 25% and 90% for a catastrophic dam failure, Chambers said.

“A worst-case failure model must be run in order to provide emergency planners with the information needed to protect against loss of human life, and to avoid building critical public infrastructure in areas that could be inundated by an unplanned release of tailings,” Save the Scenic Santa Ritas said.

Hudbay said it’s currently reviewing concerns raised during the public comment period on the draft aquifer permit, including comments regarding the dam breach analysis it submitted as part of its application.