First copper mining operation in U.S. since 2008 officially launches in Florence

The first U.S. copper mining operation in almost two decades was officially launched on Oct. 6 in a celebration that included Florence Copper executives, town officials, community members and U.S. Environmental Protection Agency Administrator Lee Zeldin.

The event ended a 10-year battle between the company, the town and local residents who were concerned over potential damage to underground drinking water reserves near residential areas.

In 2012 Florence Copper sued after the town condemned the company’s office buildings. A year later the town, under former Mayor Tom Rankin, filed several lawsuits and administrative appeals to block the company’s state and federal permits.

The town argued that using a sulfuric acid solution to extract copper could harm the local groundwater supply.

A 2019 ruling in Maricopa County Superior Court said Florence Copper had a valid right to mine because of a 2003 development agreement with the town that allowed the landowner to operate a copper mine.

Two years later the Arizona Court of Appeals agreed with the Superior Court ruling, and the town of Florence settled the dispute, withdrawing its petitions against the EPA permits and dropping all other claims.

The EPA granted Florence Copper a permit in 2023 that would allow the company to begin commercial production.

“The rigorous review and oversight has been an important part of our success so far,” said Stuart McDonald, President and CEO of Trekor Metals, the North American-based parent company of Florence Copper.

McDonald was joined by Florence Copper General Manager John Mays, Florence Mayor Keith Eaton and Zeldin at the opening event.

“To think that it’s been a couple of decades since the last time a moment like this for such a precious, valuable resource like copper,” Zeldin said.

McDonald said field operations actually began last November, and the first round of copper production started in February. ​

The last copper mining project in Arizona on untouched land was in 2008. Florence Copper said it is the first to use in-situ copper recovery for commercial production in Arizona.

McDonald said that despite recent announced cuts to Arizona’s share of Colorado River water, the area’s groundwater will remain unaffected.

“We do things in a very, very environmentally sound way. In fact, this mining method that we use actually uses significantly less water than a typical copper mine,” he said.

McDonald said Florence Copper is expected to produce 85 million pounds of copper every year for about 22 years.

Trekor Metals President and CEO Stuart McDonald shakes hands with U.S. Environmental Protection Agency Administrator Lee Zeldin. They both spoke at the official launch of Florence Copper’s new mining operation in Florence, Ariz., on Tuesday, Oct. 10. 2026. (Photo by Aiden Hanley/Cronkite News)

Eaton said Florence Copper has demonstrated that the mining method is eco-friendly and not harmful to drinking water.

“They just continued to be transparent, just over and over,” he said. “They were adamant about making sure we understood the process and that it was safe.”

According to the American Geosciences Institute, in-situ mining involves dissolving the copper in place, underground, using a solution of water and sulfuric acid, then processing it at the surface without removing rock.

Open pit mining, like operations in Morenci and Miami, Arizona, extracts copper ore that is close to the Earth’s surface.

Eaton said residents of Florence appreciate the in-situ mining because it keeps the ground intact, unlike conventional mining.

“It’s kind of boring to go out there into their mine area because it’s just a bunch of pipes,” he said.

Eaton presented the mining company with a key to the town, and congratulated Florence Copper on its progress thus far.

“Let this moment be a reminder that our greatest resource in Florence is not what lies beneath the soil but the people who live above it and the strong lasting partnerships we build together,” he said.