• You are here: EPA Home
• Region 8
• Superfund
• Colorado Cleanup Sites
• Captain Jack

Superfund Program

Captain Jack Mill

Site Type: Final NPL City: Ward County: Boulder Street Address: T1N R73 W, SE 1/4 Sec. 12, Lefthand Creek Road ZIP Code: 80481 EPA ID: COD 981551427 SSID: 08A3 Congressional District: 2

What's New?

Updated August 2010

Over the past several months, the Colorado Department of Public Health and Environment (CDPHE) and EPA have been engaged in the processes of receiving monies for site work, obtaining access from property owners, and contracting the design of the waste rock and tailings consolidation, capping and re-grading. This entailed developing a request for potential contractors to submit their qualifications. Once these were received, they were reviewed and analyzed, and in early 2010 CDPHE awarded a contract for designing the remedy for surface contamination.

The contractor can begin field work as soon as CDPHE and EPA obtain access agreements from pertinent property owners in the area. The contractor will need access to these properties in order to collect additional samples that will clearly distinguish contaminated from uncontaminated areas, and provide information on geophysical properties required to determine the best location for consolidating and covering contaminated materials. In addition, some property boundaries may be surveyed to ensure total understanding of relevant property ownership. This work should begin in the summer of 2010.

Surface Remedy Design

CDPHE has begun designing the remedy for the surface contamination (Alternative 2c in the Record of Decision). Design for the subsurface is expected to begin in the fall of 2010. CDPHE will be conducting pre-design investigations in the area soon. Contractors will be in the field to collect soil borings in existing tailings ponds, waste piles and the proposed repository locations where mine wastes will be consolidated and covered. In addition, efforts will be made to identify areas where clean soil can be excavated to cover the consolidated wastes. The potential to use local or imported rock as cover material will be investigated as an alternative.

Top of Page

---

Site Description

The Captain Jack Mill site is located at the headwaters of upper Left Hand Creek about 1.5 miles south of Ward in Boulder County, Colorado. The site is in a narrow valley known as California Gulch. Mining for gold and silver in the region began in 1860 and ended in 1992.

View site location map (opens in pop-up)

View map of the Superfund site and Operable Unit boundaries (PDF) (2.7MB)

The site is comprised of the Big 5 Mine (the upper mine), Captain Jack Ltd. Mill, the Black Jack Mine (the lower portal), and other mines and waste features in the immediate surrounding area. The Big 5 Mine, located about 500 feet upstream from the mill, consists of an adit (tunnel), a large waste rock pile and a settling pond. The mill works area includes several lagoons previously used for settlings tailings from the mill. The lower portal includes the Black Jack adit and the contents of a shed.

In June 2008, EPA and CDPHE completed the site's final Remedial Investigation and Risk Assessment report and Feasibility Study report (RI/FS). The FS report contains a detailed analysis of remediation alternatives for various site components. The proposed plan presented EPA and CDPHE's preferred alternative for the remediation of the site. A public meeting was held July, 2008 giving the community a chance to comment on the preferred remedy.

Overview of Selected Remedy

The selected remedy for cleaning up the Captain Jack Mill Superfund Site has two components, as it controls both surface and subsurface contamination sources.

To control subsurface contamination, the remedy (Alternative 3B in the RI/FS) consists of an installed bulkhead, mine pool mitigation, and phased successive biochemical reactor treatment. The concrete bulkhead will plug the draining mine adit, impounding the mine water. The mine pool environment will have reduced oxygen levels which, coupled with an injected pH adjustment compound (example: sodium hydroxide), will increase the pH of the water to a neutral condition (Phase I). If necessary, after approximately two to three years of neutralization, CDPHE may install a series of biochemical reactors outside of the mine (Phase II). The reactors use microorganisms to transform hazardous contaminants into non-hazardous substances. Following bioreactor treatment, the water would flow through wetlands for additional “polishing” treatment before entering Lefthand Creek. Because of uncertainties over the mine workings, there will be extensive groundwater monitoring once the bulkhead is installed.

Under the selected surface remedy (Alternative 2C), all waste will be excavated and placed in several on-site consolidation cells. The selected remedy calls for excavation of all site material containing contaminants of concern in concentrations above the remedial action levels.

To contain the waste, each consolidation cell will have a cap. The caps will likely consist of a liner impervious to water, coarse material to prevent rainwater from seeping down and contacting the waste, and topsoil to support vegetation. Before the liner is placed on the waste, alkaline material would be mixed into the top six inches of the waste material to minimize acidic leaching. Officials will fully evaluate potential locations for the consolidation cells, as well as locations from which to borrow dirt for the cap, during the design phase.

Top of Page

---

Site Risk

Adit drainage was found to be highly acidic in July 1986. In September 1986 the Mine Safety Health Administration found improper storage of chemicals. EPA removed several drums of chemicals and concentrated mine wastes in March 1987.

The Colorado Mined Land Reclamation Board received reports of dumping of mine and mill wastes into Left Hand Creek in October 1992. At the same time a milky white substance was reported in Left Hand Creek. Tailings-like material was observed entering Left Hand Creek from the unlined tailings ponds, turning the creek a milky gray color for about 6 miles downstream.

Sampling found high levels of zinc, cadmium, copper and lead. The Left Hand Water District shut off their drinking water intake 15 miles downstream on Left Hand Creek. CDPHE issued a Notice of Violation and a Cease and Desist Order. The Colorado Department of Minerals and Geology (CDMG) obtained a restraining order to prevent further mill operations.

CDMG determined in 1993 that there was a threat to the environment from the tailings through blowing dust, surface flooding, overflow of the tailings pond and subsurface groundwater percolation. They also determined that there were improperly stored drums and explosives. A 1997 EPA inspection found elevated levels of heavy metals in the soils from the Big 5 Mine waste pile and pond and in the unlined lagoon at the Captain Jack Mill. EPA also confirmed the findings of earlier elevated levels of metals in the adit drainage.

The Left Hand Water District uses water from Left Hand Creek as a drinking water source. Their water intake has not been impacted by the site, but the potential for contamination exists in the future. The Town of Ward’s drinking water supply is located up-gradient and is not impacted by the site.

Media Affected	Contaminants	Source of Contamination
solid waste, soils, surface water	zinc, cadmium, copper and lead	wastes from mining and smelting operations

Top of Page

---

Cleanup Progress

With the completion of the RI/FS for the site in the spring of 2008, CDPHE and EPA presented a proposed plan for alternatives for the design and construction of the site remedy for public review and comment. Following a public comment period, a remedy was selected and a Record of Decision (ROD) produced. Following the ROD, design and construction of the remedy will begin.

Anticipated Project Schedule:

Top of Page

---

Community Involvement

Community involvement plays an important role in the Superfund process. EPA uses a number of different tools and resources to promote effective, on-going, meaningful community involvement. The goals of the Superfund community involvement program are to:

• Keep communities affected by sites informed throughout the cleanup process
• Provide opportunities for communities to comment and offer their input about site cleanup plans
• Facilitate the resolution of community issues tied to a site

EPA and CDPHE provide the public with information about the cleanup of the Captain Jack Mill Superfund Site through fact sheets, press releases, public meetings, public notices published in the local paper and a community involvement plan. EPA and CDPHE also maintain information in the Site Information Repository, located at the Boulder Public Library, and also at EPA, CDPHE and Boulder County Health Department offices. Site Documents can also be viewed on this website.

CDPHE, EPA and the Lefthand Watershed Oversight Group (LWOG) have hosted meetings with community members to update them on site activities and proposals. Local citizen volunteers have formed the Lefthand Creek TAG Coalition (LCTC) to monitor the cleanup of the Captain Jack Mill site. Aided by a Technical Assistance Grant (TAG) of $50,000 from EPA, LCTC hired an independent technical advisor to help interpret and comment on site-related information.

Top of Page

---

Reuse

EPA places a high priority on land reuse as part of its Superfund response program mission. The Agency tries to select cleanup options that encourage and support future use of a site. We use two fundamental methods to facilitate reuse of Superfund sites:

• Exploring future uses before the cleanup remedy is implemented, an approach that gives the Agency the best chance of designing cleanup remedies to support the likely future use of a site
• Working with landowners and communities to remove barriers not considered necessary for the protection of human health or the environment at those sites where remedies are already in place

One option for reuse is the siting of clean and renewable energy projects on contaminated (or formerly contaminated) lands. As part of this effort, EPA is evaluating the potential for energy projects on these properties and working with landowners and communities to identify ways to remove barriers to such projects.

Top of Page

---

Land Use Controls and Other Institutional Controls

Land use controls are the most common type of institutional control (IC). ICs are administrative or legal controls that help reduce the likelihood for human exposure to contamination. ICs can also help protect the integrity of the remedy. Examples of ICs are:

• Zoning ordinances
• Environmental covenants
• Deed notices
• Well-drilling restrictions
• Building permits
• Informational advisories

EPA will determine the specific ICs later in the cleanup process, following the remedial action.

Top of Page

---

Five-Year Reviews

EPA or the lead agency conducts five-year reviews following the start of a Superfund cleanup when contamination is left on the site. These reviews are repeated every five years. We use these reviews to determine:

• How the remedy is working
• If the remedy remains protective of human health and the environment

Five-year reviews are not yet required at this site.

Top of Page

---

Site Documents

You will need Adobe Reader to view some of the files on this page. See EPA's PDF page to learn more.

Best way to open a very large file: right-click and save it to a folder.

Community Involvement Plan, updated November 2009 (PDF, 26 pp, 1.3MB )

Record of Decision, September 29, 2008 (PDF, 247 pp, 8MB )

Proposed Plan, June 2008 (PDF, 18 pp, 496K )

The following very large files are located on the publicly accessible Captain Jack FTP site:

Top of Page

---

Contacts

---

Site Information Repositories

Top of Page

---

Photo/Video Gallery

Click on a thumbnail below to view the full size image.

• 

  Big 5 adit portal

• 

  Big 5 mine dump

• 

  Left Hand Creek

• 

  Sign of caution displayed by EPA and CDPHE

• 

  Remains of mining and smelting operations

Top of Page

---

Links

Captain Jack site at the CDPHE Hazardous Materials and Waste Management Division

CDPHE/HMWMD Records Center

Lefthand Creek TAG Coalition

ATSDR Public Health Assessment and Health Consultations for the Captain Jack Mill Superfund Site

Top of Page

---

 

 

About Region 8

Area Navigation

• A-Z Index
• About Region 8
• News & Events
• Grants

  ---

• Air
• Water
• Superfund
• Waste
• Revitalization
• Green Building and EMS
• Enforcement & Compliance
• Tribal Nations