At  the meeting of the Santa Cruz County Advisory Panel on the South32 Hermosa Project, held February 16 in Patagonia, Hermosa Project President Pat Risner addressed some of the concerns raised in the community surrounding the announcement of the completion of the Hermosa Project pre-feasibility study (PFS).

Commenting on the outcry that ensued after the Australian mining company released only a 40-page summary of the PFS, rather than making public the entire document, which is reported to run over 1000 pages, Risner explained that it had never been the company’s intention to release the entire report. It was only meant to be an “internal document,” he said, to “provide information to an internal review board and senior leaders” of South32.  

This clearly had not been the understanding in the community, as Risner several times over the past three years had responded to questions about the project by saying that the answers would not be available until the completion of the pre-feasibility report. “I certainly was looking forward to the release of the pre-feasibility study because I was led to believe that it would be full of a lot of information to answer many questions that I had,” Chuck Klingenstein, of Patagonia, said. “I wish South32 had made it clear up-front that we would only see an edited summary.”

The presentation included some of the findings in the pre-feasibility report. South32 describes the Taylor deposit at the Hermosa Project, as “one of the largest undeveloped zinc-lead resources in the world and the largest in America.” The company estimates that it will cost “an additional $1.7 billion in capital investment to construct the operation.”

The company is also “reviewing integrated development” of the Clark deposit, which lies above the Taylor deposit. The Clark deposit contains manganese, zinc and silver. Still in the exploratory stage are the Flux and Peake prospects. 

Risner discussed the study’s findings on traffic in Patagonia and Sonoita, an area of concern for many members of the community. He stated that initially there would be less than 30 “loaded concentrate trucks leaving Hermosa” daily. That number would rise to 65 ore trucks daily after three years, and peak at 80 trucks.

This number, however, represents only one-way trips and does not include the number of empty ore trucks returning to the mine. In a subsequent email, Risner wrote that “some of our trucks will be staged at port, and others will be staged at site, so not every truck will make a round trip each day.” Even though a truck might not return to the mine on the same day, it still has to return at some point, so it seems reasonable to assume that the number of trucks may be less on a given day, but on other days could be greater.

More importantly, this number of trucks does not include other vehicle traffic going to and departing from the mine, such as large mining trucks, mining shovels, dozers, drilling rigs, graders, loaders, water trucks, commuter buses, reagent chemical trucks, construction supplies, service vehicles, employee vehicles and others. “Our intention is to have all of our heavy-duty traffic use the Cross Creek Connector,” Risner responded in the email exchange, referring to the planned route that would avoid trucks having to travel on Patagonia town roads, but would send these vehicles either north through Sonoita up to Tucson or south on SR82 through Patagonia.

Risner stated that there were 100 “direct employees” presently working at the mine. From 2023 – 2025, they predict that there will be 400 employees, from 2025 – 2026 (the construction stage of developing the mine) there would be 600 employees, and, as the mine becomes operational in 2027, there would be 500 – 600 employees. If these employees all drove to the mine, that could add up to 857 commuter vehicles travelling along SR 82 and SR83. (600 employees x 2(round trip) x 5 days/wk / = 857 vehicles / day). In the email, Risner assured that “Our future workforce would not be driving to site but would instead use park-and-rides at yet-to-be-determined locations around the county.” If every one of the employees was transported by bus, that would add approximately 20 buses travelling to and from the mine daily. One would assume that they would not be spread out evenly over the day but would be concentrated at the beginning and end of shifts, having a greater impact on traffic during those times. 

South32 has stated that the Cross Creek Connector (CCC) route would be the “short term” route until they can develop the Flux Canyon route south of Patagonia. The CCC route would send much of the mine traffic through Sonoita and up SR 83. Any traffic headed south would travel on SR82 through Patagonia. The Flux Canyon route would potentially send ore trucks south to Nogales, possibly to a proposed railhead in Rio Rico, or to the port in Guaymas. Because the Flux Canyon route will require NEPA (National Environmental Policy Act) approval, this process could take a decade to complete.  

Both these routes raise issues of concern for commuters, first responders, Border Patrol, school bus drivers, tourists, local businesses, hunters and visitors to the area. When asked what the company was doing to allay these fears, Risner wrote, “For some time now, we have been engaging with the local community about our route selection process through publicized open houses – two in Patagonia, and one in Sonoita – and through public meetings with elected officials…This engagement process is ongoing and will extend to farther reaches as we gain more clarity about things like port selection and off-site infrastructure needs. Our next open house is taking place on March 24 from 4 to 6 p.m. at the Patagonia High School courtyard.” 

All stakeholders, including residents and business owners, are encouraged to attend this event to learn more about South32’s plans and to express their concerns.