- South32 has completed its $30 million voluntary remediation project at the former Trench Mine, a closed mine last operated more than 50 years ago on the present-day Hermosa Project site in Arizona
- They have constructed a state-of-the-art dry stack tailings storage facility which remediates over two million tonnes of waste from the historic mine
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The history of Hermosa
Located in the Patagonia Mountains approximately 80 kilometres south-east of Tucson, Arizona, the historic mine site once known as the Trench Mine, had not operated for 50 years.
The Hermosa Project, a development option near the Town of Patagonia, was acquired by South32 as part of its $1.3 billion acquisition of Arizona Mining in August 2018.
With a goal for net-zero emissions and water recycling, South32 has completed a $30-million voluntary remediation project project to protect ground and surface water near the site. The Trench mine’s ancient tailings storage facility has also been redesigned as a dry stack system.
Hermosa comprises two major mineral deposits, Taylor and Clark, and is now projected to be one of the top four zinc producing mines in the world.
Creating the “State-of-the-art” dry stack tailings storage facility
“There were some legacy environmental issues at the site that we inherited that needed to be cleaned up. South32 was able to complete this cleanup by working with the State of Arizona through their Voluntary Remediation Program focusing primarily on some old mining waste piles called tailings, “ said Pat Risner, Hermosa President.
“It’s a win for the environment, and that’s first and foremost. It’s a win for South32, because they have a viable mine site, and they’re going to be able to be in that area for a long time. And it’s a win for the agency, because we know we have a site that is being managed appropriately and works well with the agency to address any of our concerns.”– VRP program director for ADEQ Laura Malone
South32, which is based in Perth, Australia, operates mines throughout the world. Hermosa is its first project in North America. It has set a company-wide goal to create net-zero emissions at all of its operations by 2050. The company is among today’s growing list of mining companies focused on the environment and sustainability in response to climate change, strict regulatory controls, and public demand.