Reclamation and Closure

Black Cloud Mine, Leadville, Colorado

EA provides inundation mapping services to our clients that inform the public of flooding risk. Using a combination of hydrologic, hydraulic, and mapping expertise, EA produces inundation maps that are accurate and easy to comprehend. These maps are essential for emergency responders to rapidly evacuate residents downstream of a dam if an issue were to arise. EA also provides FEMA permitting and river restoration mapping services using similar tools.

Umetco Minerals Corporation, Hot Springs, Arkansas

EA designed and supervised construction of an embankment raise of the 125-foot-high tailings dam and developed a reclamation plan to be implemented during continued operation of the tailings impoundment. The raise and reclamation work improved the existing drainage system and overall stability of the impoundment. The project included subsurface investigation and piezometer installation, flood routing and spillway design, seepage analyses and blanket design, cover design, stability analyses, liquefaction analyses, and construction oversight.

Umetco Minerals Corporation, East Gas Hills, Wyoming

EA designed reclamation plans for an above-grade uranium tailings impoundment, a below-grade tailings impoundment, evaporation ponds, and mined pits. EA staff performed site-wide hydrology, characterization of the groundwater and geochemistry, risk assessment for clean-up of radiological contaminants, seepage analyses, stability analyses, and radon attenuation analyses. The reclamation plans were approved by the U.S. Nuclear Regulatory Commission.

Babbitt Ranches, Coconino County, Arizona

EA was the lead consultant for development of the removal action related to historic uranium mining activities on land currently under the control of Babbitt Ranches near Cameron, Arizona. The site consists of abandoned mining units within two sections of land that were under an Agreement and Order on Consent (AOC) for Interim Removal Action. The scope of work included development of a Health and Safety Plan, Quality Assurance Project Plan, Field Sampling Plan, Data Management Plan, Quality Management Plan, Background Determination and Gamma Scanning Plan, and Removal Site Evaluation report, all of which have been approved by the U.S. EPA. Review entities included U.S. EPA Region IX, Arizona Department of Environmental Quality (ADEQ), Arizona State Lands, Bureau of Reclamation, and the Navajo Nation. EA and their team have worked directly with the EPA and other agencies through the review and comment process to obtain approved work plans.

Minera Yanacocha/ Newmont, Cajamarca, Peru

EA completed unsaturated flow modeling and geochemical analyses for the drain down and rinse of a heap leach pad for final closure at the Yanacocha Mine. The project consisted of modeling the projected discharge rate from the pad during and after closure. The geochemical properties of the discharge solution from the heap leach pad during and after the proposed progressive closure were also modeled to determine the projected duration of longterm monitoring and potential water treatment requirements.

Idarado Mining Company, Telluride, Colorado

EA staff provide services for the Idarado Mining Company, a subsidiary of Newmont, at their facilities in Telluride and Ouray, Colorado. Services provided by EA staff have included collection and disposal of tailings from impacted sites, stream stabilization, maintenance facility design, activities associated with preservation of the historic Pandora Mill building, and water management for the historic Bridal Veil Power System. Water management activities for the Bridal Veil hydroelectric system include Engineering, Procurement, and Construction Management (EPCM) services for rehabilitation and maintenance of nearly four miles of historic pipelines supplying water to the Bridal Veil Powerhouse. The facility, operated under a FERC permit exemption, provides electricity to the Town of Telluride and the San Miguel Power Association. EA provides project management and engineering services for rehabilitation, replacement, and maintenance of the pipelines that supply water to the powerhouse, including dam safety programs for the two high-mountain storage reservoirs that supply water to the project. EA’s project managers coordinate with Newmont, Telluride, San Miguel County and FERC managers, and Colorado Dam Safety officials to ensure the safe and efficient operation of the system.

Idarado Mining Company, Telluride, Colorado

EA staff provide services for the Idarado Mining Company, a subsidiary of Newmont, at their facilities in Telluride and Ouray, Colorado. Services provided by EA staff have included collection and disposal of tailings from impacted sites, stream stabilization, maintenance facility design, activities associated with preservation of the historic Pandora Mill building, and water management for the historic Bridal Veil Power System. Water management activities for the Bridal Veil hydroelectric system include Engineering, Procurement, and Construction Management (EPCM) services for rehabilitation and maintenance of nearly four miles of historic pipelines supplying water to the Bridal Veil Powerhouse. The facility, operated under a FERC permit exemption, provides electricity to the Town of Telluride and the San Miguel Power Association. EA provides project management and engineering services for rehabilitation, replacement, and maintenance of the pipelines that supply water to the powerhouse, including dam safety programs for the two high-mountain storage reservoirs that supply water to the project. EA’s project managers coordinate with Newmont, Telluride, San Miguel County and FERC managers, and Colorado Dam Safety officials to ensure the safe and efficient operation of the system.