#AnimasRiver: Bonita Peak Mining District Superfund site update

From The Durango Herald (Jonathan Romeo):

This summer will be the first full work season since the Bonita Peak Mining District Superfund site was declared last September, and the Environmental Protection Agency is wasting no time trying to figure out one of the biggest mysteries in the watershed: The American Tunnel.

EPA hydrologist Ian Bowen said this week the agency plans to drill 500 feet into the San Juan Mountains to install a monitoring well between the second and third bulkheads on the tunnel…

The American Tunnel, which travels about 11,000 feet, served as a transportation route for ore, as well as a deep drainage, from the vast Sunnyside Mine workings to facilities at Gladstone, north of Silverton.

When Sunnyside Mine closed for good in 1991, attention turned to what to do with acidic discharges out of the American Tunnel. Sunnyside initially pulled the water into a treatment plant, but ultimately decided with the state of Colorado to install three bulkheads to stem the flow of acid drainage.

But in recent years, researchers believe the Sunnyside mine pool behind the American Tunnel reached capacity and the water is spilling into other mine networks, such as the Gold King and Red & Bonita…

The Animas River headwaters are broken into three drainages: Mineral Creek, Cement Creek and the Upper Animas.

Rebecca Thomas, project manager for the Bonita Peak Mining District Superfund site, has previously said each drainage accounts for about a third of heavy metal loading in the Animas, causing a dead zone of aquatic life on the river from just below Silverton to the Bakers Bridge.

But many people familiar with the basin say the EPA, which could see massive budget cuts under the Trump administration, should focus on the high-metal content waters of Cement Creek, where 13 of the 48 sites are located…

Treatment options for the American Tunnel are a great unknown, Bowen said.

Some have called for a complete draining of the tunnel, which could take decades and cost a lot of money to treat discharges. Others have suggested placing bulkheads on all the mines in the area.

Bowen said the EPA first needs to understand the hydrology of the area. The new monitoring well that is expected to be installed by August will be a key tool in that effort because it will provide insight on how much water is behind the bulkheads, he said.

“There’s strong indications that these systems are related, but there’s not enough evidence to say it’s immediately connected,” Bowen said.

Sunnyside Gold Corp. has long contended there is no connection between the American Tunnel and any other mine networks in the area.

The American Tunnel drains about 100 gallons of acid mine waste water a minute, which flows right by the EPA’s temporary treatment plant into Cement Creek.

The temporary treatment plant only takes discharges from the Gold King Mine, which is now at about 620 gallons a minute. The EPA said it may consider treating other mine discharges upon further evaluation.

From The Farmington Daily Times (Hannah Grover):

The second annual Conference on Environmental Conditions of the Animas and San Juan Watersheds with Emphasis on the Gold King Mine and Other Mine Waste Issues today at San Juan College also featured other people who have been monitoring conditions in the rivers.

One challenge for scientists is identifying to what degree metals are naturally occurring in the river and which metals are coming from mines in Colorado.

Kathleen Sullivan, a U.S. Environmental Protection Agency scientist, said heavy metals released into the river during the Gold King Mine spill likely are no longer in the sediments in the rivers.

Sullivan said there are naturally high levels of aluminum and iron in the river because of the composition of the bedrock. She said the EPA looked at the ratio of arsenic and lead to aluminum or iron in the river to identify the plume released by the Gold King Mine spill.

The ratio peaked while the plume was passing through the area…

She said only a small fraction of the heavy metals released into the river during the spill reached Lake Powell in Utah and Arizona during the immediate aftermath of the spill in August 2015. The rest of the metal was deposited as sediment, but Sullivan said the EPA believes the metals from the Gold King Mine spill are no longer present in the sediment and now have been deposited in Lake Powell.

Sullivan said the EPA believes the Gold King Mine metals deposited in sediments passed through New Mexico in low levels over three to four weeks during the spring runoff in 2016.

To test that hypothesis, Sullivan said the EPA took samples during the spring runoff this year. She said the EPA expects to see lower ratios of lead to aluminum in this year’s samples.

Sullivan said the metals in the plume of acid mine drainage were mainly picked up after the water left the Gold King Mine. She said the water exiting the mine picked up a large amount of metal from a waste pile outside the mine. Sullivan said the EPA is currently in the process of testing that pile.

During a panel presentation, Bonnie Hopkins, an extension agent for New Mexico State University, said one of the biggest issues still facing the area is the public stigma associated with the spill.

When Farmington’s Growers Market opened for the 2016 season following the Gold King Mine spill, only three vendors showed up to sell their products. She attributed the small number of farmers selling their products to the stigma surrounding crops grown using water from the Animas River.

This year, the Growers Market saw improvement. Hopkins said 11 vendors brought crops to the first market of the season earlier this month.

During a panel discussion, Sullivan said the acid mine drainage from the Gold King Mine is effectively being treated, although drainage from other mines needs to be addressed. She said samples from Cement Creek — which feeds the Animas River — show the water quality is improving.

Steve Austin, a hydrologist with the Navajo Nation EPA, said community outreach is still needed to communicate that the river water is safe.

From The Denver Post (Bruce Finley):

EPA Superfund officials trying to stop toxic mine contamination of the Animas River headwaters are preparing to close an underground dam, aiming to block a 300 gallon-per-minute discharge equal to a Gold King Mine disaster every week.

Shutting this Red and Bonita Mine bulkhead has emerged as a huge test on mountains here, where miners who penetrated fissures and groundwater pathways left behind the geologic equivalent of Swiss cheese…

But turning a valve and closing that bulkhead could trigger toxic leaks elsewhere, potentially spreading harm along already-contaminated headwaters. The EPA’s latest water data show widespread aluminum, cadmium, copper, iron and zinc contamination from mining and natural sources at levels too high for fish to survive.

EPA officials this week told The Denver Post — and assured local leaders — that the agency will use caution at the bulkhead, installed in 2004, and close it gradually next year while monitoring mountainsides for any new leaks. They’ve launched a data-gathering blitz, harnessing the local Mountain Studies Institute, to measure flows from dozens of mine tunnels and more than 97 mountainside seeps and springs.

“As soon as we feel we have a good handle on what the baseline is, then we’ll close the Red and Bonita bulkhead,” EPA project chief Rebecca Thomas said. “We would do it as a test initially and build up water behind the bulkhead.

“If we see a change we’re not comfortable with, if it is going to cause any further degradation of water quality, we’ll open up the bulkhead and drain it and treat it,” Thomas said in an interview.

“We need to understand how water flows before we close it. There are a lot of underground connections. Some are man-made. Some are natural,” she said. “We want to test whether or not closure of the bulkhead would help us improve water quality by stopping continued flow from the Red and Bonita.”

EPA hydrologist Ian Bowen said environmental gains could be big but emphasized unknowns. For example, the acid-metals muck draining from the Gold King, which is filtered before it mixes into the Animas, increased last year, reaching to 710 gallons per minute. The EPA can treat 1,200 gallons per minute at a plant below that mine.

Bulkheads also were installed inside Kinross Corp.’s Sunnyside Mine and American Tunnel. EPA crews plan to drill behind those bulkheads to test the pressure of pent-up mine wastewater — to make sure they will hold. American Tunnel bulkheads still leak 100 gallons a minute, and the Mogul Mine, where a bulkhead was installed in 2003, leaks 150 gallons a minute more unfiltered muck into headwaters.

Stopping the untreated Red and Bonita discharge would mark a first big fix in a Superfund cleanup following the Aug. 5, 2015, Gold King disaster, where an EPA crew accidentally triggered a 3 million gallon spill that turned the Animas mustard-yellow as it moved down the river and eventually reached the Grand Canyon of the Colorado River.

Installing more bulkheads to trap toxic mine muck inside mountains could mean taxpayers pay less for water cleaning at treatment plants built along headwaters.

Colorado “agrees with EPA’s plan,” state health department spokesman Warren Smith said.

Yet challenges loom. Mapping tunnels, fissures, seeps and springs increasingly occupies a legion of researchers and Deere & Ault engineering consultants tapped by the EPA. They anticipated in an April report that closing the Red and Bonita bulkhead would cause toxic overflows elsewhere. And EPA bureaucracy combined with uncertain funding from Congress has delayed a dozen or so other toxic mine Superfund cleanups around Colorado — let alone the tens of thousands of inactive mines contaminating water around the West.

East of Silverton, above Creede, the EPA’s Superfund cleanup of the Nelson Tunnel and various old mines — declared a national-priority disaster in 2008 — has yet to move beyond studies of tunnels and groundwater.

EPA officials on Wednesday said the agency “is evaluating the focused feasibility study for the (Creede) site and considering a range of alternatives for the proposed remedy” but that, because the EPA has not picked “a preferred alternative,” funds for cleanup aren’t available…

EPA crews seem to be working at sampling water and investigating hydrology before closure of the Red and Bonita bulkhead, said Fetchenhier, who is a geologist. “We said: ‘Before you close it, we want the data gathered on every spring, every seep, every tunnel so that you have a baseline. Anytime you put in a bulkhead, there is a chance something could come out someplace else.’ ”

EPA officials this week convened a forum in Silverton, an in-depth hydrology session with a brain trust of local scientists, mining engineers and others whose collective knowhow, federal officials said, exceeds the agency’s expertise.

Downriver in Durango, La Plata County leaders acknowledged a strong interest in stopping contamination after decades of enduring the toxic legacy of mining — because clean water is crucial for residents of Colorado and other western states.

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