Heavy metal pollution diverted from Uncompahgre River in Colorado’s San Juan Mountains.
Report by Tanya Ishikawa , Communications Coordinator of the Uncompahgre Watershed Partnership
Ridgway–The Uncompahgre River should be running a little bit cleaner this fall after contaminated water flows from abandoned mines were remediated this summer. The Uncompahgre Watershed Partnership (UWP), a nonprofit in Ouray County focused on river restoration and preservation, completed two mine remediation projects in close collaboration with Jeff Litteral, a project manager for Colorado’s Division of Reclamation, Mining and Safety.
Heavy metal pollution from abandoned mines in the San Juan Mountains are a major source of contaminants in the Uncompahgre. Though the river above Ridgway Reservoir is not used as a local drinking water source, it is an important agricultural, recreational, aquatic and wildlife resource. Water from the reservoir is also used for those purposes as well as for municipal water downstream as it runs through Montrose, Olathe and Delta.
“UWP’s remediation projects at three legacy mine sites in the Upper Uncompahgre Watershed address metals loading and acidic mine drainage to streams that do not meet beneficial uses for aquatic life, recreation, water supply or agriculture. Consequently they are on the EPA’s Clean Water Act’s list of impaired waters,” explained Agnieszka Przeszlowska, UWP mine remediation project manager.
Funded by Colorado Department of Public Health and Environment grants, UWP began cleanup efforts at three mines last year. The first task, completed in July and October 2014, was to collect surface water samples and river insects from the Upper Uncompahgre River. These samples will be compared to future samples taken after remediating the polluted flows to determine how much water quality improves.
The first site to be remediated was the Michael Breen Mine, where the polluted drainage from a collapsed mine entrance was flowing from the mine across Engineer Pass Road and into the Uncompahgre River. This high alpine portion of the river was found to contain toxic levels of cadmium, copper, zinc and manganese, which impair aquatic life.
UWP constructed a diversion ditch to re-route the mine discharge and reduce leaching of metals into the river in October 2014. Re-routing the water also eliminated pooling under the load-out structure, stopping destabilization of the structure. This August, a one-acre area adjacent to the diversion ditch and former drainage area was re-vegetated with a mix of native seeds, anchored by an early ground cover species, a soil amendment and aspen mulch. Chris Peltz of Silverton-based Research Services LLC assisted with design of re-vegetation prescriptions and installation.
The second completed remediation project was at Vernon Mine, where two draining mine entrances were leaching significant amounts of copper into Gray Copper Gulch. Besides the copper levels, this stream has been identified as having poor water quality due to iron and a low pH, which impair aquatic life.
This September, construction crews removed approximately 1,000 cubic yards of waste rock from the Gray Copper Gulch valley floor, and hauled it uphill to a repository in a flat area away from hill-slope runoff and drainage areas. Two mine entrances were closed off and a small diversion ditch was constructed to redirect drainage from one entrance. Strategic portions of the area were also re-vegetated with a high alpine mix, soil amendments and aspen mulch.
The third project is at Atlas Mill, an abandoned mill off Camp Bird Road above Sneffels Creek. Mine tailings from legacy operations have been deposited in the creek’s floodplain, and erosion of the tailings and runoff during spring snowmelt contribute heavy metals, especially cadmium and zinc, to the stream, impairing aquatic life. UWP is collaborating with the operators of Ouray Silver Mine, Inc., which is the property owner of areas within the project, and consulting with Western Stream Works LLC on project design to minimize erosion of tailings in the floodplain. Project implementation is planned for summer 2016.
“We all remember the recent and dramatically visible Gold Mine spill of three million gallons of polluted water into the Animas River. Yet, every day hundreds of Colorado abandoned mines leak toxic heavy metals into our waterways – largely unnoticed and forgotten. UWP is proud to have the opportunity to partner with the State of Colorado, private mine owners and contractors, and other stakeholders to begin to tackle this problem one step at a time,” said UWP Board Member Scott Williams.
The Uncompahgre Watershed Partnership (UWP) exists to help protect the economic, natural, and scenic values of the Upper Uncompahgre River watershed in southwest Colorado, U.S.A. The Partnership works to inform and engage all stakeholders and solicits input from diverse interests to ensure collaborative restoration efforts in the watershed, which starts high in the San Juan Mountains, flows past amazing Rocky Mountain vistas and dozens of abandoned mines, and ends up in the Colorado River headed to California and Mexico. For more information about UWP, please see uncompahgrewatershed.org.
Tanya Ishikawa, the UWP Communications Coordinator, is an award-winning writer and editor, who specializes in environmental and cultural topics as well as film. She is also a video producer, focussing on documentaries for nonprofits. She can be contacted by email.