Captain Jack Superfund Site

Mining activity began in 1861 following the discovery of gold and silver in the mountains west of Boulder. This area is part of the Front Range (or Colorado) Mineral Belt, a linear zone of mineral-rich rock that is coincident with the eastern slope of the Rocky Mountains. Miners flocked to the area by the thousands, […]

Water quality issues were likely occurring since mining began in the area. By 1938, the Left Hand Ditch Company formed a Pollution Committee and filed suit against some of the mines for damage to the creek. Acid mine drainage (AMD), commonly called Yellow Boy because if it’s orange- yellow appearance, caused vegetation and aquatic life […]

Approximately 12 mines were operated in the headwaters area of the Left Hand Creek watershed by the early 1900’s. Each mine can involve a labyrinth of tunnels and shafts that extend in many dimensions and levels below ground. By 1934, the Captain Jack Site was built as a central hub for many surrounding mine workings. […]

After nearly a century of activity under multiple owners at the Captain Jack Mine, the site shut down in 1992. In the ten years prior, the Captain Jack Ltd. Company cleaned out the Big Five Tunnel adit and covered the tailings with hundreds of tons of waste rock and a couple other companies failed to […]

By 2003, Captain Jack Mill was listed on the EPA’s National Priorities List (NPL) because the water in Left Hand Creek continued to show impacts of acid mine drainage and the public were concerned about impacts to health, safety, and the environment. In 1999, the EPA approached the Towns of Ward and Jamestown about the […]

In 2008, Captain Jack Mill Superfund site completed a final Record of Decision (ROD). The ROD is a pivotal point in the Superfund Remediation Process, as it defines the approach that will be used to clean up the site and the monitoring indicators that demonstrate cleanup performance and completion. The Remedial Action Objectives (RAOs) for […]

The surface remediation occurred from 2011 to 2013. This work aimed to reduce human exposure to harmful toxins in the tailings and other waste materials, and reduce exposure of tailings and waste to groundwater and surface water runoff. To achieve this, waste rock and material were consolidated into two cells within superfund project area. These […]

The Subsurface Remediation began in late 2015. This work aims to reduce the negative impacts of acid mine drainage (AMD) using novel remediation techniques that will require no long-term operations. The work focused on treatment within the inner mine workings at the Big Five Tunnel and initially included (1.) installing a bulkhead to fill the […]

In October 2018, Left Hand Creek landowners reported a fish kill up to 10 miles downstream of the Captain Jack Mine. The fish kill was a result of a standard practice emergency mine pool release conducted by the EPA and CDPHE in September 2018. Prior to the release, the bulkhead flow-through valve was shut, and […]

After the emergency release and resulting fish kill, the sub-surface remediation activities were paused as the EPA and CDPHE, and contractors were hired to revisit the approach. While the original goals of the remedy remained the same, new methods and techniques were tested in Summer 2020 and implementation continues today. These updated activities include: (1.) […]