From atop the black mass of the East Helena slag pile, Environmental Protection Agency project manager Betsy Burns pointed to the features of an engineered floodplain and creek channel where Prickly Pear Creek will one day flow.
Heavy machinery revved and chirped below -- to the east digging the channel, and to the west constructing a cap of rock and topsoil over contaminated material below the surface.
“Every day you come out here it’s pretty amazing the amount of material they’ve moved,” Burns said.
In 1998, contamination from Asarco’s lead smelter resulted in a multimillion dollar settlement with the EPA for violations of the Resource Conservation and Recovery Act (RCRA) and the Clean Water Act. The smelter closed in 2001, and after later declaring bankruptcy, Asarco placed about $95 million in a trust managed by the Montana Environmental Trust Group for related cleanup costs.
The trust has spent approximately $25 million to date, Burns said, which is “on track” with budget expectations. The majority of material used has been available on site and crews moved about 500,000 cubic yards of material this season, she added.
One limiting factor in the cleanup is the $95 million available, which contributed to decisions such as leaving contaminated materials in place in favor of lowering groundwater, Burns said.
“You plan for the cleanup you’re doing knowing you have a finite amount of dollars and need money left at the end for long-term operations and maintenance,” she said.
Construction season typically begins in May, with work continuing through November or December until weather shuts crews down, said Marc Rhodes, trust group construction manager.
“As long as it isn’t 30 below they’ll probably continue to push right on through,” he said.
The cleanup project employs about 70 contractors, consultants and federal workers, although numbers fluctuate, he said. Local contractors such as Helena Sand and Gravel and Envirocon were awarded much of the work, he added.
While the larger East Helena-area cleanup is funded through Superfund, the cleanup of the smelter, which was still open when the violations were discovered, is occurring under RCRA. The regulations direct implementation of “interim measures” ahead of a final cleanup plan. EPA has implemented three interim measures starting in 2012 aimed at protecting groundwater and public health, Burns said.
“There are a lot of unique aspects to the site but it’s pretty clear what we need to do,” she said.
Groundwater flows through soils contaminated with selenium and arsenic, causing plumes stretching into East Helena and further into the valley. Dealing with that pollution means stopping it at the source, Burns said.
The first interim measure underway calls for dropping groundwater levels by removing a surface water dam and moving the creek with the goal of lowering groundwater below contamination.
The second interim measure is the current construction of an engineered cap on the old plant site intended to prevent surface water from penetrating contamination.
The third interim measure is the evaluation and, when necessary, removal of contaminated material to onsite landfills. Because the locations of 100 years of contaminates is largely anecdotal, testing is still revealing the extent of the pollution, Burns said.
“It’s hard to see the tremendous amount of work that is happening here, but we’re starting to see success,” she said. “The groundwater has dropped about 10 feet and we’re starting to see some (contamination) concentration drops.”
Whether the measures can ultimately cause the plumes to recede remains to be seen, she said.
“Eventually the hope is that the water would be clean and that eventually those plumes will start to recede,” Burns said. “How long that’ll take, I can’t really tell you. The goal is to protect public health and the environment, and in the meantime being sure no one is being exposed to contaminated water.”
Restrictions are also in place via a water protection district for tapping groundwater in the areas of the plume.
Much of the work to clean up water beneath the surface is hidden by the slag pile looming above East Helena. The No. 1 question EPA is asked about the cleanup is what will happen to the slag, she said.
“The slag itself is pretty inert, but that’ll be the next phase of what we’ll be looking at,” Burns said. “We’re first looking at the plumes and dealing with sources, and now we’ll see how the slag pile is impacting the environment.”
Evaluations of the slag starting next year will examine potential leaching materials and its contribution to groundwater pollution, she said. Moving the creek is one step to alleviate potential risks from the slag as the creek undercuts the pile in some places, she added.
The trust will look at interest in reprocessing the slag as companies have been able to recover metals from similar material and make it economical, Burns said.
The slag pile is the first thing on most people’s minds when it comes to the cleanup, but East Helena Mayor James Schell said he hopes residents understand that the first priority is human health and addressing the plumes. Both federal and state officials have been good to work with and open to the public on the path forward and available for explaining very complex issues, he said.
As East Helena plots its future, recognizing the history of the smelter is something Schell believes is important.
“Times are changing, but there are still a lot of folks that worked or had relatives that worked at the smelter,” he said. “It’s a hugely important aspect of this community, and I see potential both in public use of the site and public education of its history, because it was one of the best in the world.”
An exciting aspect of the cleanup is talk of future public access to the section of Prickly Pear Creek currently under construction, Schell said. The area can become both a place for recreation and education, he said.
The sight is being designed with the intention that it will be accessed by the public, Rhodes said, but nothing is formal.
The cleanup goes far beyond just the smelter site, and includes cleanup of trust lands impacted by the smelter. Schell said he is optimistic that developers will see potential in the lands as cleanup continues.
“I’m looking forward to another chapter for East Helena,” Schell said. “These are major activities moving forward aesthetically and for public health that will be very beneficial to our community.”
The EPA’s final cleanup plan, called a corrective measures report that will evaluate the effectiveness of the three interim measures, is expected in 2017.