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Helena says Ten Mile Creek was much more contaminated than EPA reported

Ten Mile Creek Mine Leak

A settling pond is pictured Wednesday where mine waste settles before entering Ten Mile Creek near Rimini.

Water samples taken by Helena staff in Ten Mile Creek following the Environmental Protection Agency's mine waste spill show severely higher levels of metals and arsenic than the federal agency's test results indicated.

During the Helena City Commission's Monday meeting, City Manager Rachel Harlow-Schalk updated the commissioners on the status of what the EPA is referring to as "a burp" that caused mining sediment from the long abandoned Susie Mine, part of the larger Upper Ten Mile Creek Mining Area Superfund site, to spill into Ten Mile Creek on July 12.

According to the EPA's on-site coordinator operating in the area, Duc Nguyen, less than 100 gallons of water mixed with mining sediment was released into the creek below the city's water treatment plant intakes.

Ten Mile Creek Mine Leak

Contractors and the EPA just finished remediating the old mine shaft where a blockage caused the mine waste to spill into Ten Mile Creek.

The EPA's water samples were reportedly taken July 12 downstream of the discharge. The agency recorded arsenic levels at about 0.15 milligrams per liter of water. Iron was at 0.48 milligrams per liter. Zinc was measured at 0.3 milligrams per liter.

However, city staff took their own water samples on the same day, the results of which show 31.2 milligrams of arsenic per liter of water and nearly 23 milligrams of zinc per liter of water at the site of the spill.

Discrepancies in the results could be attributed to the location of sampling, though Harlow-Schalk said that based on conversations with EPA representatives, that sampling occurred in roughly the same place.

"If you were to look at the EPA's results, the order of magnitude and concentration compared to ours, which were at the discharge point, are nearly 100 times higher for metals than what they had reported," Harlow-Schalk said. "For example, arsenic for us, our sample was almost 3,000 times higher than the city's discharge permit would allow."

The city is permitted to discharge only a certain amount of contamination into Ten Mile Creek from the water treatment plant.

"So what was in the creek and what had been discharged was very different than what had been shared to the community," she said.

Still, during an interview on site Wednesday, Nguyen said there is no concern.

"To be honest, any movement in the creek channel, that's what you'll see," he said, pointing to a small but dense plume of orange flowing into Ten Mile Creek.

Ten Mile Creek Mine Leak

Duc Nguyen, EPA's on-site coordinator operating in the area, left, and Marc San Filippo talk about work done to remediate a recent mine spill into Ten Mile Creek near Rimini.

His crew of three has since built a settling pond below the mine entrance that will help remove the sediment before the water flows into Ten Mile Creek. That pond was constructed using limestone to help balance the water's pH.

A spillway from Susie's entrance was also built out of limestone. It runs about 40 feet below to the settling pond before crossing under Rimini Road into a second spillway, eventually ending in Ten Mile Creek.

Bales of hay and fabric sacks have been placed strategically along that route to further collect sediment.

The blockage at the entrance of the mine has also been removed. The slope of earth above the entrance was re-groomed to prevent future collapses.

And the more than 100,000 gallons of contaminated mine runoff and acidic sludge that built up behind the section of mine that collapsed in 2016 was siphoned out and trucked away to Luttrell Repository.

"We're pretty much wrapped up," said Marco San Filippo, a member of the EPA crew working at the site. "We'll be coming back though to monitor."

Ten Mile Creek Mine Leak

A settling pond is pictured Wednesday where mine waste settles before entering Ten Mile Creek near Rimini.

City staff discovered the spill July 12, the day it occurred, and reportedly contacted the EPA and Montana Department of Environmental Quality.

Helena Public Works Director Ryan Leland previously told the Independent Record the city had not been contacted about work the EPA was doing in the area, nor did the city receive notice of the spill.

"With our water supply being right there, it would have been nice to know about the work they are doing," Leland said.

During Monday's meeting, Harlow-Schalk said the lack of communication by the EPA is concerning.

"I get that it's about, you know, the cleanup, and they're working hard, but that's not why I'm concerned," she said. "I'm concerned that they can't call 911 when they have an emergency, and I shared that with them as well. ... They owed us a call, and they owed it to the people playing in the creek that day. That was really the big picture of it. They owe a conversation to us, and that's at 911. It's not hard to find us."

Nguyen said the EPA follows strict reporting and notification protocols that, in this case, do not involve the city of Helena. He said the EPA has a national response center that disseminates reports of every spill, burp or blowout, and that the onus is on the DEQ to pass that information along.

"It's impossible for us to notify everybody," he said. "The residents here (in Rimini) are our primary concern."

Nguyen said the residents of Rimini have been hospitable to him and his crew.

"People are very supportive," he said. "They like what they see because the water quality will be better."

Ten Mile Creek Mine Leak

Duc Nguyen, EPA's on-site coordinator, stands along Ten Mile Creek where the mine spill drains into the creek after it works through a settling and filtering process near Rimini.

Harlow-Schalk said in an interview Tuesday she is still concerned.

"If they felt this was no big deal, that's alarming," she said. "In this scenario, the EPA is expected to follow the Clean Water Act. In this scenario, they did not follow that act."

In her update to the commissioners Monday, she said "we'll continue to work with the EPA to get the best information we can for the community."


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Local Government and Crime Reporter

Nolan Lister is a reporter at the Helena Independent Record with an emphasis on local government and crime.

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