silver lake reclamation project...american smelting and refining company trust animas river...
TRANSCRIPT
Silver Lake Reclamation Project
1
2013 National Association of Abandoned Mined Land Programs
Abandoned Mine Land Reclamation Award Nomination
Submitted May 6, 2013
Project Name: Silver Lake Project
Project Location: Silverton, San Juan County, Colorado
Submitted by:
Colorado Division of Reclamation, Mining and Safety
Inactive Mines Reclamation Program
1313 Sherman Street, Room 215
Denver, Colorado 80203
Kirstin Brown, Project Manager
Steve Renner, Senior Project Manager
Project Details:
Reclamation Construction Begun: June 26, 2012
Reclamation Construction Completed: September 15, 2012
Reclamation Construction Cost (OSMRE only): $265,900.00
Reclamation Construction Total Cost: $564,875.00
Parties Involved in Reclamation Process:
Project Design, Bidding, Construction Management: Colorado Division of Reclamation, Mining and Safety - Inactive Mine Reclamation Program
Project Partners:
Office of Surface Mining, Reclamation, and Enforcement
Colorado Department of Public Health and Environment
American Smelting and Refining Company Trust
Animas River Stakeholders Group
K and P Property Design, LLC
Colorado Division of Reclamation, Mining and Safety
Mountain States Historical
San Juan County Historical Society
Bureau of Land Management
Silver Lake Reclamation Project
2
Introduction
The Silver Lake hardrock mine reclamation project is located in San Juan County in southwestern
Colorado, four miles east of the town of Silverton. At 12,186 feet elevation, Silver Lake is a high
mountain “hanging lake” or tarn, located at the end of a steep 1.5 mile pack trail from the trailhead at
the Mayflower Mine Road in lower Arrastra Gulch. Elevations of the project area are extreme,
ranging from 11,400 to 13,200 feet. The glacially carved topography of Silver Lake Basin is
excessively steep and rugged and the climate is harsh. Frigid temperatures are encountered most of
the year, accompanied by tremendous avalanche danger in winter and spring.
The project was developed as a joint effort between the Colorado Division of Reclamation, Mining
and Safety (CDRMS), the Colorado Department of Public Health and Environment (CDPHE), and
the Animas River Stakeholders Group (ARSG) to safeguard mine openings on properties belonging
to the American Smelting and Refining Company (ASARCo) around Silver Lake. CDPHE manages
funding for safeguarding and environmental restoration of ASARCo properties in San Juan County
as part of a court-ordered ASARCo bankruptcy settlement with Colorado. CDRMS’s Office of
Surface Mining Reclamation and Enforcement (OSMRE) funding and State Severance Tax funding
were used to safeguard the hazardous legacy mine openings, so that a significantly larger portion of
the ASARCo settlement funds can instead be utilized for large scale environmental restoration
projects to remediate acid mine waste and acid mine drainage sites in the watershed.
Silver Lake Mine Safety Closure Map, showing the location of Silverton and the ASARCo claims.
Silver Lake Reclamation Project
3
Silver Lake Mining History
The Silver Lake claim was staked by John Reed and prospecting in and around Silver Lake began in
1876. At that time, the Silver Lake, Iowa, Royal Tiger, and Buckeye mines on the edges of the lake
were some of the richest mines in the State of Colorado. The Silver Lake Mine was one of the
largest and most complex mines in the American West. At one point, the Silver Lake Basin housed
500 workers year round in boarding houses, one of which was 5 stories tall, with running water and
flushing toilets at the turn of the century. Continually developed by The Stoiber family, Silver Lake
Basin can lay claim to the longest aerial mining tram, one of the first AC power grids and largest
power plants, as well as innovative milling practices for the time period. In 1901, the Guggenheim
family purchased the Silver Lake mining empire from Edward Stoiber, and in 1903 the Guggenheim
operations merged with the American Smelting and Refining Company (ASARCo). ASARCo was
keen on owning and operating mines in Silverton to feed its smelter located downstream in Durango,
Colorado. ASARCo was the primary landowner in Silver Lake Basin until its bankruptcy in 2005.
The history of Silver Lake Basin is well preserved due to the remoteness of the site. Most of the
relics of mining's past remain on-site, with three buildings still standing, and much of the mining
equipment still in place. All of the historic buildings around Silver Lake have either collapsed under
heavy snow loads or have been destroyed by avalanches. Some buildings were lost to various fires
during mining operations. Silver Lake Basin is an important part of the history of San Juan County.
The integrity of the site will remain intact due to the remote location.
Silver Lake, town site in forefront, power substation and assay office still standing. This was the location of the five
story boarding house and multiple other buildings.
Silver Lake Reclamation Project
4
The mines in Silver Lake Basin are complex and interconnected with winzes, stopes, ore shoots, and
shafts. The complexity of the mine workings also makes the mine openings extremely dangerous
due to extensive vertical workings and the possibility of inadequate ventilation leading to oxygen
deficiency which can asphyxiate persons venturing too far underground.
Project Partnerships and Funding
The safeguarding of the Silver Lake Mines became a priority for CDRMS when ASARCo went
bankrupt and settled in court to provide clean-up funds for their legacy mining sites scattered
throughout the United States. The Silver Lake area received approximately 4.5 million dollars as
a set aside to clean-up and reclaim the ASARCo properties. CDRMS, CDPHE, and ARSG made
the Silver Lake mine safety closures a priority, so that the majority of funding could be preserved
for future environmental clean-ups to improve water quality in the Animas River. In 2010, the
project was funded by Colorado’s annual Office of Surface Mining, Reclamation, and
Enforcement (OSMRE) grant. OSMRE provided approximately half of the necessary funding,
and State Severance Tax funding filled in the remainder.
The Silver Lake Mine Site is an important part of Silverton's history and is a popular and well
known day trek. The San Juan County Historical Society and Mountain States Historical were
supportive of the project because of their interest in preserving the historic nature of the site.
Silver Lake is a treasure trove of historic mining machinery. Pictured here are parts of a steam pump, a column-
mount drill, and a pulley for a tram. Extreme care was taken to preserve the history of the site.
Silver Lake Reclamation Project
5
Reclamation Plan
Utilizing Trimble GPS mapping and detailed land status analysis, property ownership and
individual mine safety closure specifications were developed. Due to the remote location and
high elevation, CDRMS opted to survey Silver Lake in one focused event utilizing seven
employees to locate the dangerous mine openings. Fifty-two mine safety closure locations were
identified and characterized using the CDRMS developed Mobile Brasscap application on the
Trimble GPS units. The data was then uploaded into the Brasscap database, which is Colorado's
mine safety closure database. Land Status was determined using ArcMap to georectify Land
Status Maps from the BLM, CDPHE, San Juan County, and ASARCo.
The mine safety closures were selected and designed to blend in with the historic nature of the
site. Closures of the mines were determined based on the attributes of current accessibility and
historic significance of the mines. The San Juan County Historical Society assisted with site
design by providing recommendations for grates and doors for certain locations. Grates with
doors were specified for many of the adits, so that visitors would be able to view the
underground mine workings from the safety of the surface, and private landowners could still
access their mine workings. Rock bulkheads made with locally scavenged rock from around the
site were specified for adits with less historical significance, or for mine openings that were
already collapsing and unstable. Vertical openings of significance were specified for grates with
doors, and special consideration was taken for excessive snow loading at these high elevations.
The reclamation plan included specifications for minimally impacting the site during
construction. Helicopters were required for all transportation of materials and equipment in
order to minimize land disturbance.
CDRMS crew at Silver Lake in 2010, developing the mine safety closure project
Silver Lake Reclamation Project
6
Reclamation Construction Challenges
A number of unique and challenging issues were encountered, and eventually overcome, during
the life of the project. The Silver Lake mine safety closure project was an extremely remote
project located at a historically treasured location. The historic nature of the site was preserved
through meticulous attention to preserving the site. CDRMS specified appropriate closures for
historic sites while the contractor, K and P Property Design, LLC, was extremely careful to
maintain the historic look of the sites by avoiding historic objects or timbers, and working
around the object or incorporating the materials into the closures.
The very short construction season at this elevation was a challenge. The project was bid and
shown a year in advance, with the contractor allotted two summer seasons to complete the
project. K and P overcame the challenge of the short construction season by utilizing over
eleven workers and splitting into as many as four crews. One crew was responsible for materials
staging and helicopter delivery of materials. The other three crews were responsible for
installing mine closures.
The project presented significant challenges for delivery of materials and supplies to the high
elevation mine safety closure locations. CDRMS specified that helicopters would be required for
project execution. K and P opted to utilize a helicopter at least 3 days a week to transport
supplies around Silver Lake Basin. The use of the helicopter drastically reduced the time the
project took and lessened the impact to the sensitive alpine tundra environment.
The remote location of the project was also challenging for daily construction crew access. Due
to the long arduous steep hike up the headwall and into Silver Lake Basin from the trailhead
Helicopters were required by CDRMS, and K and P utilized helicopters three days a week to deliver materials to work locations
around Silver Lake Basin.
Silver Lake Reclamation Project
7
lower down in Arrastra Gulch, K and P crews opted to camp at Silver Lake three nights each
week. K and P set up a minimalistic camp and endured the cold nights, rainy days, and profuse
lightning and thunder at an extreme elevation for the duration of the project.
Safety was another challenge due to the remote location and adverse weather. The crews were
constantly aware of the dangers of lightning and found shelter whenever necessary, often several
times each day! All crews were in contact via radios provided by the helicopter company, New
Air Helicopters. K and P had an additional staging area at a cabin directly below Silver Lake
Basin with additional crew members posted there in case of an emergency on the mountain.
Happily, there were no safety incidents or injuries during the project.
Reclamation Construction
The project Pre-Bid was held in September 2011 and the project was awarded to K and P Property
Design, LLC (K&P) for a low bid of $563,775.00. Two summer seasons were allotted in the project
schedule for construction, but K&P completed the work in less than three months during the summer
of 2012.
The Silver Lake Project was a meticulously organized and expertly constructed project. Due to the
remoteness of Silver Lake Basin, a helicopter from New Air Helicopters, LLC out of Durango,
Colorado was used on a near daily basis to deliver materials and transport people around Silver Lake
Basin. Construction materials and tools were staged at Gold Lake in Little Giant Basin and the
helicopter long-line dropped the materials at the mine openings. K&P camped on-site Monday
through Thursday during construction on the south side of Silver Lake. Thirty horizontal mine
openings (adits), 18 vertical openings (shafts and stopes), and one hazardous facility (water well)
were safeguarded using closure methods that included hand backfills, steel-grated shaft closures,
polyurethane foam closures, corrugated steel adit closures, grated adit closures, rock bulkhead
closures, and wire rope netting closures.
Mine safety closures were blended into the site, to maintain the historic integrity of Silver Lake Basin. Personnel from the
ASARCo Trust periodically observed some of the construction activities during the closure installations.
Silver Lake Reclamation Project
8
Here are two vertical openings closed with grates and locking doors. The closures blend into the surroundings, while
providing safety to hikers and backcountry enthusiasts.
CDRMS and the contractor went above and beyond to blend the closures with the surroundings. On the left is a walkway and hand
railing installed over a grated stope. The trail historically went directly over the open stope, via a collapsing bridge of loose material.
The trail was maintained over this grated mine safety closure. On the right a worker installs the lock in a bulkhead closure.
Silver Lake Reclamation Project
9
Reclamation Success
The overall site work involved difficult access, remote locations, high elevations, and extremely
dangerous mine openings in a historically sensitive, popular hiking area. CDRMS was able to
overcome the challenges and install mine safety closures that preserve the history of Silver Lake
Basin, saving ASARCo restoration trust funds for future hardrock environmental clean-ups. The
success of this project is therefore two-fold: Great success achieved in meeting the challenges of an
extreme remote location, steep topography, alpine storms, historic nature of the site, and the short
construction season; coupled with the successful partnerships formed with local and state entities to
preserve funding available for use on environmental clean-ups to improve water quality. By using
Colorado’s OSMRE funds to address the physical mining hazards in this remote area, more of the
trust fund is available to improve the aquatic health and water quality in the Animas River.
Silver Lake, a “hanging lake” or “tarn” at 12,186 feet
above MSL in the upper glacially-scoured cirque basin
above Arrastra Gulch and the Animas River