To avoid flooding of mine tunnels at the Hermosa Project, Arizona Mining Inc. (AMI), a subsidiary of South32, plans to “dewater” the Patagonia Mountains at an estimated rate of 4,500 gallons per minute. To protect any downstream aquifers from being loaded with pollutants that exceed Arizona Dept. of Environmental Quality’s (ADEQ) Aquifer Water Quality Standards (AWQS), ADEQ granted an Aquifer Protection Permit (APP) to discharge treated effluents into Harshaw Creek.

That decision was appealed by me after reviewing the data produced by AMI, where it failed to “demonstrate that pollutants discharged through dewatering would not cause or contribute to a violation of AWQS at the Point of Compliance,” as required by law. I argued that “ADEQ has not shown that the human health and environment downstream of Harshaw Creek would be protected from discharges of treated water.” 

Upon hearing the evidence, the Arizona appeals judge decided that AMI had met the requirements for the permit. The judge ruled that I had “presented evidence that goes beyond what the APP program regulates, e.g., the bio-accumulation of metals in soils and vegetation, which information cannot be a basis to overturn ADEQ’s decision to issue the permit.” ADEQ’s own appeals board then quickly adopted all of what the judge proposed in his “Decisions.”

Using questionable water infiltration rates and without any professional sensitivity analysis, AMI estimated that the discharged surface water changed completely into groundwater at the surprisingly exact distance of 9.36 miles from the discharge point. This happens to be shortly before Harshaw Creek reaches the alluvial planes of Sonoita Creek – the relevant Point of Compliance. Therefore, AMI argued, no potentially polluted discharge water would be reaching the impaired waters of Sonoita Creek, which would have been a reason to deny the Permit.

In contrast, I presented flash flood data obtained from public data and our own measurements, done with Patagonia citizen Dave Ellis, showing that flows of similar rate of discharge would reach Sonoita Creek within hours. 

Moreover, the judge accepted ADEQ’s “concept” that during the journey down Harshaw Creek, it is “possible” but “not likely” that pollutants will be picked up by discharge water and cause an exceedance of AQWS before it has fully infiltrated as groundwater. Consequently, AMI argued that there is no need for an actual Point of Compliance, only a “conceptual” one, i.e., one that does not need any monitoring of pollutants, let alone demonstrate that exceedances are taking place or not.

That concept was disproved by a 2012 University of Arizona thesis study on metal mobilization in the Patagonia Mountains. The Sonoita Creek soil pollution measurements that US Geological Survey (USGS) area specialist Floyd Gray added to this study leave no doubt about the contribution that Harshaw Creek flash flood water added to the pollution of Sonoita Creek. The subsequent bio-availability (not “bio-accumulation,” as erroneously quoted by the judge) of such contaminants to vegetation and grazing cattle confirms the earlier (2007) USGS designation of the Patagonia Mountains as a “mineralized ecosystem.”

ADEQ runs its own soil characterization programs but, in contrast to USGS, it has not engaged in such activities in the Patagonia Mountains since their joint 2002 pollution assessment report of Harshaw Creek. That report was limited in its scope, and without soil data, few meaningful conclusions could be made. This did not escape the attention of the Auditor General who concluded in 2021 that ADEQ has been “limited in its ability to keep waters and soils safe from pollution.” 

In short, ADEQ has not shown any data that disproved my claim that the human health and environment downstream of Harshaw Creek would not be protected from discharges of treated water. In fact, ADEQ has shown itself incapable of independently reviewing permit applications on compliance demonstrations, not opinions, that are clearly required by law.

Meanwhile, the Arizona judicial system appears to prefer opinions of a state agency over data from a federal agency, even after a public audit has shown that ADEQ fell short in its duties. 

Permits such as these allow for mining activities that cause irreversible soil contamination issues and jeopardize availability of already scarce resources like water. Mining also results in industrial scale removal of vegetation, whose presence is badly needed to help combat climate change and reduce mobilization of contaminated soils toward alluvial aquifers. Foreign mining multinationals like South32 should conduct their activities where eco-systems are much less vulnerable