ADEQ: Patagonia mine wasn't source of orange sludge

An Arizona Department of Environmental Quality official said the agency has no evidence that the orange muck came from the Trench Camp Mine lying six miles south of the town of Patagonia. It’s a statement that astonished environmentalist critics of the Patagonia area’s mining industry and contradicted a state inspection report.

Such sludge clearly did flow into Alum Gulch from an artificial wetlands near the old mine, but those wetlands aren’t part of the mine complex, said Julie Hoskin, ADEQ’s voluntary remediation program manager. Alum Gulch flows into a major tributary of Sonoita Creek. She also defended the agency’s past management of the site.

The 250-acre Trench Camp site, of which 45 acres had been disturbed for mining, lies 12 miles south of Patagonia. It’s one of two old mine sites that authorities had previously said sent contamination into area streams after the September storms. The other was the Lead Queen site on U.S. Forest Service land, about six miles south of Patagonia.

The orange discharges are important because they show the possibility of toxic heavy metals in the runoff, although the orange itself is the color of more benign iron runoff.

Patagonia activists said Tuesday that they have photos and videos showing the orange sludge came from the Trench site. They believe this stormwater pollution incident is a sign that ADEQ can’t be trusted to manage new mines properly and that they’re relying only on minimal standards. Their comments came as the federal government is reviewing four mining proposals for the Patagonia Mountains, led by the Wildcat Silver Co.’s plan for extensive drilling for a future silver mine.

The activists sent the Star photos and a video that they said show orange runoff in a tailings pond at the mine site and runoff slowly turning more orange as it moves down a creekbed. In addition, an ADEQ inspection report also suggests that reddish brown liquid was leaving the mine site for the gulch.

In reply, ADEQ said the area surrounding Trench Camp has been mined since before 1900, long before the arrival of modern-day regulations and permitting. Modern-day permits are designed to facilitate compliance with aquifer protection, the Clean Water Act and federal hazardous waste laws, the agency said, adding, “Enforcement of regulations is possible when you have a viable mining operation that has monetary consequences when not in compliance.”

Until the heavy rains of September, the Trench site, formerly owned by Asarco, had been in compliance with state requirements for several years, Hoskin said. The site was covered under a 2010 general state permit regulating mine stormwater discharges. Since that permit was approved, the site’s owners, the Asarco Multi-State Environmental Custodial Trust, had developed a stormwater pollution prevention plan that the state had approved several times, most recently in 2013.

But this month, after the orange water escaped, ADEQ cited the site’s owners, the Asarco Multi-State Trust with six violations of state water-quality rules.

Hoskin acknowledged that the Trench site had discharge problems, and noted that ADEQ’s own samples of stormwater samples leaving the site found levels of copper exceeding state standards.

But she declined to fault the agency’s past oversight of the trust’s management of the mine site. The main reason that stormwater overtopped the mine’s four tailings piles was due to the amount of rainfall, she said.

Past inspection reports from the trust’s consultant showed that some areas of the mine tailings caps had eroded in previous years, but Hoskin said that many of the erosion problems had been fixed.

“I don’t think there was any way to predict this volume of storm,” Hoskin said. “We’ve done everything on that site reasonable and necessary to prevent that from happening,” referring to the tailings breach by storm runoff.

Federal authorities, including the National Weather Service, couldn’t say whether the September storms that dropped 3 to 6 inches in the Santa Cruz County-Patagonia area were 100-year storms. Such storms are what most government agencies require new development to protect against.

Hoskin said, however, that ADEQ doesn’t know if the long-closed Trench site — where Asarco did significant environmental cleanup and remediation work in the early 1990s — was designed for a 100-year storm.

Wendy Russell, coordinator for the Patagonia Area Resource Alliance, said she was stunned at ADEQ’s denial that the orange flow came from the Trench Camp mine. U.S. Geological Survey official Floyd Gray, unavailable for comment Tuesday, had also said that the artificial wetlands were part of the Trench mining complex area.

“I was present with (an) ADEQ inspector as well as Floyd Gray from U.S. Geological Survey on Friday, Sept. 26, when the site was inspected and samples were collected,” Russell said. “It was quite clear to everyone present that the orange water was obviously flowing from the Trench tailings piles as well as the artificial wetlands pond.”

To call the erosion repairs adequate when they clearly failed forces her to question what sort of standards are required at all, Russell said.

ADEQ, however, said erosion problems weren’t the main reason the mine tailings impoundment gave out — it was that the storm water overflowed a large earthen berm at the site, and that basins carrying sediment overflowed into neighboring basins offsite.

ADEQ’s violation notice, dated Oct. 10, said that a department inspector observed on Sept. 26, a reddish brown liquid crossing a Forest Service access road, from the mine toward Alum Gulch and going down a steel culvert coming from the mine property and discharging into Alum Gulch.

“The pipe and the area were stained with the reddish brown discoloration,” said the inspection report. It added that the liquid had a pH level between 1 and 3, indicating highly acidic runoff. Typically, the lower the pH level, the more acidic the liquid.

ADEQ’s Hoskin said, however, that the samples may have contained waters mixed from several areas. But “we don’t know that for sure” and plan to visit the site soon to try to figure it out, she said. Also, before the inspector arrived there, sometime after Sept. 20, a separate water sample showed the pH level at a much less acidic level, around 6.1, Hoskin said.