Abandoned mines’ ponds tapped in firefighting effort

Bucket

DEQ

The state Department of Environmental Quality provided this photo of a helicopter-borne water bucket filling up at a pond on the Zortman-Landusky Mines site in July. The water was used to fight the so-called July Fire in north-central Montana. In the background is piping and the pond’s polypropylene liner.

During a firefighting operation in north-central Montana last month, helicopter crews hit the wildfire with water scooped from manmade ponds on the site of the abandoned Zortman-Landusky Mines.

Last Best News contacted the Department of Environmental Quality after hearing rumors that the helicopters mistakenly used water from the ponds, and that the supposedly toxic water had damaged land in the path of the fire.

Not true, according to Wayne Jepson, an environmental science specialist with the DEQ, which oversees reclamation and continuing water treatment at the old gold mine. Jepson said geologists with the Bureau of Land Management, which was leading efforts to fight the so-called July Fire, asked the DEQ about the possibility of using the ponds.

“There’s not a lot of water out there,” Jepson said. “We identified the ponds that had the best water in them.”

Jepson said there are five water-storage ponds at the abandoned mines, containing a total of about 40 million gallons of water. The DEQ oversees a two-stage water-treatment process to deal with sub-surface waters contaminated with various minerals, primarily iron, manganese, zinc and aluminum.

In the first stage, the water is treated with lime to neutralize the water, bringing it back to nearly an acid-free state and causing the metals to drop to the bottom of the ponds, which are lined with a reinforced polypropylene geomembrane.

In the second stage, a biological process removes nitrates from the water. The water used to fight the July Fire came from ponds where the acidity is virtually neutral but is still high in nitrates. Those nitrates are similar to certain kinds of fertilizer, Jepson said, so “it’s kind of like irrigating with fertilizer.”

In fact, he said, some water-treatment processes involve land application of partially treated water. This was land application with a twist, he said, in that the water was dropped from huge buckets borne by the helicopters.

Jepson couldn’t think of another instance in which mine-site water was used to fight fires, but he said a conservation district near the old Kendall Mine north of Lewistown asked the DEQ if it could keep ponds there in place even if they were no longer needed, for use in case of nearby fires.

Al Nash, a public affairs officer for the BLM is Billings, likewise was unsure how often such water was used by firefighters.

“It’s safe to say it’s uncommon,” Nash said. “I just don’t know to what degree.”

Nash said people with the BLM’s fire-suppression division had asked agency geologists to evaluate possible use of the Zortman-Landusky ponds. Those geologists determined that the ponds were rich in nitrates and had some small amounts of selenium, Nash said, but also that “these water resources were acceptable for that sort of use.”

Ponds

Lange Containment Systems Inc.

These are three of the water-storage ponds on the site of the Zortman-Landusky Mines.

The geologists then obtained permission from the DEQ before giving firefighters the green light to use the water.

The July Fire, so named because it was one of the first big fires in Montana that month, was thought to have been caused by humans and was reported on July 3. It grew to nearly 11,700 acres before being declared contained on July 19.

The fire was located between the towns of Zortman and Landusky, southeast of Hays and southwest of Lodgepole, two towns on the Fort Belknap Indian Reservation.

Pegasus Gold started developing the mines, one of the nation’s first open pit cyanide leach gold mines, in the late 1970s. Until the mines were closed down in 1998, after Pegasus Gold declared bankruptcy, they experienced several cyanide spills, including one that released 50,000 gallons of cyanide solution and contaminated a community drinking water supply.

Jepson said cyanide, which was used to separate precious metals from surrounding minerals, ceased to be a concern within several years of the mine’s closure. Cyanide is stable only in highly alkaline waters, he said, but breaks down fairly quickly in water containing lots of oxygen, like the water in the ponds maintained by the DEQ.

Pegasus did post millions of dollars in reclamation bonds, but the state on Montana assumed a sizable portion of cleanup costs, including the perpetual water-treatment.

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