California Gulch NRDAR Canterbury Tunnel Restoration

Background information. The original Canterbury Tunnel began as an idea in 1922 as a way to remove excess water in the mines that honeycomb the mountains near Leadville, Colorado. The objective of reducing the volume of water in these mines was to increase the opportunity for ore extraction. The project’s original plans were never fully realized because of technological limitations and increasingly dangerous conditions that confronted workers, and so the 4,000-foot-long Canterbury Tunnel sat dormant until the early 1960s. Historically, Leadville relied on the nearby Big Evans Reservoir as the primary source of municipal water. The reservoir’s elevation of 10,200 feet above sea level has been particularly problematic for Leadville during ... Show More

Background information. The original Canterbury Tunnel began as an idea in 1922 as a way to remove excess water in the mines that honeycomb the mountains near Leadville, Colorado. The objective of reducing the volume of water in these mines was to increase the opportunity for ore extraction. The project’s original plans were never fully realized because of technological limitations and increasingly dangerous conditions that confronted workers, and so the 4,000-foot-long Canterbury Tunnel sat dormant until the early 1960s. Historically, Leadville relied on the nearby Big Evans Reservoir as the primary source of municipal water. The reservoir’s elevation of 10,200 feet above sea level has been particularly problematic for Leadville during the cold Colorado winters because the cold water regularly caused pipes throughout the town to freeze.

In 1962, Leadville learned that the water draining out of the Canterbury Tunnel was not only clean, but it was also at a temperature of more than 50 ºF. The town decided to invest in piping and a pump station so the relatively warm water flowing from the Canterbury Tunnel could be used to supplement the town’s municipal water system and help reduce the problem of frozen pipes.

By the early 1990s, the original Canterbury Tunnel began to show signs of stress. The timbers used as support structures for the tunnel’s original construction in the 1920s began to rot and collapse causing cave-ins and blocking the water flow. By 2003, the water source flowing from the tunnel could no longer be used, which resulted in water shortages and a stressed distribution system during the winter months. In response to these shortages, the Parkville Water District in Leadville elected to re-drill and intersect the original Canterbury Tunnel above the collapsed areas that were restricting the flow of the warm water. Funds for the project came from the Colorado Department of Local Affairs, the settlement from the California Gulch Superfund site, and the Parkville Water District. Components of this project included drilling and intersecting the passageway above the tunnel’s blockage, building a new pump station, and laying an additional 8,200-foot pipe to the Big Evans Water Treatment Plant, which expanded the distribution of the relatively warm water to other parts of the municipal system that were historically bypassed by the tunnel’s original design. The project was completed in November 2012, and resulted in an average increase of 10 ºF in water temperature throughout the distribution system. As a result of this project, 2012 marked the first year on record where Leadville’s water distribution system did not experience frozen lines during the winter months.

Background information on the Canterbury Tunnel project was obtained from Laura Archuleta, U.S. Fish and Wildlife Service, and Greg Teter, Parkville Water District, written commun., 2015; and from California Gulch Superfund site Natural Resource Damage Assessment and Restoration case documents at http://www.cerc.usgs.gov/orda_docs/CaseDetails?ID=37.
 
Economic impacts. The Canterbury Tunnel project was conducted in 2012, and had a total cost of more than $1,674,000 (2014 dollars). Approximately 52 percent of project funds was spent locally, which supported an estimated 8.6 job-years; $516,000 in labor income; $769,000 in value added; and $1,702,000 in economic output within the local economy near the project site. Expanding to include both local and nonlocal expenditures, this project supported an estimated total of 21.6 job-years; $1,461,000 in labor income; $2,325,000 in value added; and more than $4,462,000 in economic output in the national economy. Show Less

Contact(s): Catherine M Cullinane Thomas, Christopher C Huber.

Overview

Project Period: 2012-2012

Location: Colorado

Restoration Type: Water infrastructure improvement

Lead Agency: Parkville Water District

Economic Impacts
National Economic Impacts (2014 dollars):

Total Project Expenditures: $1,674,000


Job-Years: 21.6 (12.9 per $1M)

Labor Income: $1,461,000 ($873K per $1M)

Value Added: $2,325,000 ($1.4M per $1M)

Economic Output: $4,462,000 ($2.7M per $1M)

Local Economic Impacts (2014 dollars):

Local Project Expenditures: $867,000

Percent of Project Expenditures Spent Locally: 52%

Local Job-Years: 8.6

Local Labor Income: $516,000

Local Value Added: $769,000

Local Economic Output: $1,702,000

Big Picture
Main Project: California Gulch NRDAR Restoration

Leadville, located in the mountains of Colorado approximately 100 miles west of Denver, was historically a rich mining district. Silver, gold, copper, zinc, manganese, and lead were all mined in the area beginning in the mid-1800s, but mining has since subsided as the main economic driver for the district. Because of environmental contamination from mining activities, the area known as the California Gulch Superfund site was placed on the U.S. Environmental Protection Agency’s (EPA’s) National Priorities List in September 1983. The site covers approximately 18 square miles in and around Leadville, Colorado, and contains thousands of piles of mine waste and drainage sites that discharge into the California Gulch from underground abandoned ... Show More

Leadville, located in the mountains of Colorado approximately 100 miles west of Denver, was historically a rich mining district. Silver, gold, copper, zinc, manganese, and lead were all mined in the area beginning in the mid-1800s, but mining has since subsided as the main economic driver for the district. Because of environmental contamination from mining activities, the area known as the California Gulch Superfund site was placed on the U.S. Environmental Protection Agency’s (EPA’s) National Priorities List in September 1983. The site covers approximately 18 square miles in and around Leadville, Colorado, and contains thousands of piles of mine waste and drainage sites that discharge into the California Gulch from underground abandoned mines. The EPA began emergency remediation at the site in 1986 and remediation continues to this day. In 2006, on behalf of the public, the Natural Resource Trustees (Trustees), which include U.S. Department of the Interior agencies and the State of Colorado, estimated damages to natural resources at the California Gulch Superfund site. The Trustees determined that the release of hazardous substances from the site, including heavy metals and acid, have resulted in injuries to groundwater and aquatic and terrestrial resources. Injured terrestrial resources include upland areas associated with mine waste deposits and floodplain areas with contaminated riparian zones, irrigated meadows, and fluvial deposits. Surface water in California Gulch has been observed to exceed the adverse effects thresholds for aquatic biota for zinc, cadmium, and other metals, and these high metal concentrations have resulted in nearly a complete loss of some biological communities (Stratus Consulting Inc., 2010).

A 2008 Natural Resource Damage Assessment settlement agreement requires the Resurrection Mining Company and Newmont USA Limited to pay $10.5 million in damages for injured natural resources resulting from the discharge of hazardous substances from the California Gulch Superfund site. Additionally, the 2009 ASARCO LLC bankruptcy resulted in a $10 million, plus interest, settlement to the Trustees. These settlement funds were used for many restoration projects in and around Leadville, Colorado, including the Arkansas Instream Habitat Restoration Project, the Canterbury Tunnel Project, and the Dinero Tunnel Project. A great deal of progress has been made as a result of these and other restoration projects in the area and, as of 2014, 70 percent of the site had been delisted from the EPA’s National Priority List. The U.S. Geological Survey collected data on restoration activities and expenditures to estimate the economic activity supported by these restoration projects.
Background information on the Arkansas River instream habitat restoration was obtained from Laura Archuleta, U.S. Fish and Wildlife Service, written commun., 2015; and from California Gulch Superfund site Natural Resource Damage Assessment and Restoration case documents at http://www.cerc.usgs.gov/orda_docs/CaseDetails?ID=37.

References Cited

Stratus Consulting Inc., 2010, Restoration plan and environmental assessment for the Upper Arkansas River Watershed: Stratus Consulting Inc., 111 p., accessed June 1, 2015, at http://www.cerc.usgs.gov/orda_docs/DocHandler.ashx?ID=152.

 

 

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