Overview
Coal Creek watershed, view to Kebler Pass from just north of Crested Butte, March, 2005.
With funding from the University of Colorado's Outreach Committee, we are assisting the聽Coal Creek Watershed Coalition聽(CCWC) in assessing the amount and location of metal inputs to Coal Creek.聽 Coal Creek is the main water supply for the聽聽in northern Gunnison County, Colorado.聽 The watershed was the site of numerous precious metal, base metal, and coal mines since the 1870s.
The two major abandoned mine sites of concern are the Standard Mine, now a U.S. Environmental Protection Agency Superfund site, and the Keystone Mine on Mount Emmons.聽 The聽Standard Mine, a former gold, zinc, lead, and copper mine, was added to the聽National Priorities List聽in 2005, and聽remediation is underway.聽 The Keystone Mine, a former copper, lead, cadmium, and zinc mine operated from the 1960s to the 1980, discharges about 1,000 gallons per minute of acidic mine drainage.聽 The drainage is treated in the Mount Emmons treatment plant, which is owned and operated by聽U.S. Energy.聽 U.S. Energy is interested in mining the molybdenum deposit below Mount Emmons.
Brianna Shanklin (M.S., 2006) samples Coal Creek in September, 2005, during low flow.
Our research on Coal Creek has focused on the sources of metals -- mainly zinc, cadmium, copper, and lead -- in the watershed.聽 To do this, we have conducted聽metal loading tracer tests聽pioneered by the U.S. Geological Survey for their聽Abandoned Mine Lands Initiative.聽 For these tracer tests, a salt for which stream transport is essentially conservative (e.g., lithium chloride, sodium bromide, sodium chloride) is steadily injected at an upstream injection point and its arrival at some downstream point is monitored by specific conductance.聽 Dilution of the salt concentration along the stream is used to determine stream discharge.聽 Once the stream contains a constantly-injected amount of the salt, a synoptic sampling is performed between the upstream injection point and the downstream monitoring point.聽 The synoptic sampling is a "snapshot" (with the samples collected as quickly as possible) of the salt and metal concentration in the stream.
We have now performed two of these tests over 9 kilometers of Coal Creek, from above Elk Creek, the tributary that carries metals from the Standard Mine site to Coal Creek, to the north side of Crested Butte, near the confluence of Coal Creek with the Slate River.聽 The first test was conducted in September, 2005, for low-flow conditions.聽 The second test was conducted in June, 2006, for high-flow conditions.聽 The results of these tests are currently being analyzed and turned into reports for the CCWC.聽 A preliminary version of the low-flow report is currently available (Shanklin and Ryan, 2006).聽 In June, 2006, we also collected sediment and benthic macroinvertebrate samples from Coal Creek to examine the record of metal inputs not detected during the tracer tests.聽 Reports on the high-flow tracer test and the sediment and benthic macroinvertebrate sampling will be delivered in early 2007.
The Standard Mine Superfund Site as it appeared in July 2005. The acidic, metal-laden water in this pond overflowed into Elk Creek, which carried the water to Coal Creek.
The work on Coal Creek has been carried out by one Master of Science graduate, Brianna Shanklin, and one Bachelor of Science candidate, Hallie Bevan.聽 Brianna's thesis, which was completed in August, 2006, examined metal transport in Coal Creek at low flow.聽 Hallie's thesis will present the results of the high-flow tracer test.聽 Two summer students, Frannie Bui (Drexel University) and Scarlett Graham (Allegheny College), conducted the sediment and benthic macroinvertebrate sampling as part of a National Science Foundation Research Experience for Undergraduates summer program.
Projects
- Assessing the Effects of Abandoned Mines on Water Supply for the Coal Creek Watershed Coalition, Crested Butte, Colorado聽, University of Colorado Outreach Committee, 2005-2006, PI: Joseph Ryan
Collaborators
- Coal Creek Watershed Coalition, Anthony Poponi, Coordinator
- Christina Progess, Standard Mine Superfund site manager, U.S. Environmental Protection Agency, Region 8
Summer REU students Scarlett Graham and Frannie Bui collect sediment and benthic macroinvertebrate samples from Coal Creek.
Student Theses, Reports, and Presentations
- Shanklin B., 2006.聽Sources and effects of mining-related and natural acid rock drainage quantified using tracer dilution, Coal Creek watershed, Gunnison County, Colorado, M.S. thesis, Civil and Environmental Engineering, University of Colorado at Boulder.
- Shanklin B. and Ryan J.N., 2006 (preliminary).聽Sources of Metal Contamination in the Coal Creek Watershed, Crested Butte, Gunnison County, Colorado: Part I. Low Flow, September 2005.聽Report 06-01, Department of Civil, Environmental, and Architectural Engineering, University of Colorado at Boulder, 82 pp.
Publications and Presentations
- Sources and effects of mining-related and natural acid rock drainage quantified using tracer dilution, Coal Creek watershed, Gunnison County, Colorado, presented by Brianna Shanklin, M.S. thesis defense, July 21, 2006.
- Sources and effects of mining-related and natural acid drainage quantified by streambed sediment sampling in the Coal Creek watershed, Gunnison County, Colorado, presented by Frannie Bui, Research Experience for Undergraduates final seminar, July 10, 2006.
- Metals in the benthic macroinvertebrates in Coal Creek, Gunnison County, Colorado聽(presentation), presented by Scarlett Graham, Research Experience for Undergraduates final seminar, July 10, 2006.
News
- KBUT-FM Crested Butte, September 15, 2005,聽Coal Creek Water Quality.
Aerial photograph (Google Earth) of the Mount Emmons treatment plant, Keystone Mine, and the gossan and iron fen.
Prof. Joe Ryan wading Coal Creek with a kick net to collect samples of benthic macroinvertebrates.