Broadbent is actively working on abandoned mine land (AML) projects, and over the past decade, we have developed a streamlined approach for this work. Our database management expertise enables us to provide solutions to efficiently and cost effectively analyze and display AML site features. We are also experienced with various assessment and remediation techniques, including acid mine drainage capture and treatment, mine pool mitigation, and passive treatment. With safety at the forefront, our protocol includes mitigation measures for risks associated with site access and environmental and physical hazards commonly present at these remote, mountainous locations. Broadbent’s experience also includes work on high-profile sites such as Comstock Archaeological Mill Site Surveys, Eureka Smelter Site Removal Action, Leviathan Mine Early Response Action, and the Anaconda Copper Mine Site in Yerington, Nevada, as well as numerous other sites across the western United States.
A differentiator of the Broadbent team is our in-house archaeology expertise in historical mining. This experience provides an important understanding of mining means and methods and potential contaminants associated with processing activities (e.g., mercury or cyanide). This ability brings focus, efficiency, and value to AML projects.
Our overall AML experience includes:
- AML Site Inventory and Database Management
- Conceptual site model (CSM) development
- Cultural Resource Management (CRM)
- Underground mine pool mitigation
- Passive treatment
- Preliminary assessment/site inspection (PA/SI)
- Remedial action design and implementation
- Removal action implementation
- Unmanned Aircraft System (UAS) aerial surveys
Abandoned Mine Land Assessment and Remediation Resources
Nevada Division of Environmental Protection – Abandoned Mine Lands Branch
Nevada Division of Minerals – Abandoned Mine Lands Program
Nevada Bureau of Mines and Geology – Mining Districts Files
Bureau of Land Management – Abandoned Mine Lands
United States Forest Service – Abandoned Mine Lands
Trout Unlimited – Abandoned Mine Lands
Nevada Division of Environmental Protection (NDEP) AML Branch PA/SI
Working closely with the NDEP AML Branch, Broadbent has completed over 100 AML site assessments since 2016. Through these assessments, we have developed innovative and efficient approaches utilizing GIS and database solutions.
Broadbent staff performing PA/SI at abandoned mine site in Nevada.
Birthday Mine Non-Time Critical Removal Action, Humboldt County, Nevada
Working for the NDEP AML Branch, Broadbent performed a CERCLA Removal Action at the Birthday Mine, a legacy gold mine in Humboldt County, Nevada. The project goal was to characterize and address arsenic impacted mine drainage emanating from a mine pool behind an adit plug. Broadbent characterized and designed a safe method for draining the mine pool and treating the water via an onsite passive treatment system. Use of passive methodology achieved project goals while ensuring minimal O&M costs.
Mine pool well drilling, adit drain, and passive arsenic treatment system installation, Birthday Mine, NV.
Eureka Smelter Site Removal Action, Eureka, Nevada
Eureka, Nevada is considered the “birthplace” of silver-lead smelting in America, historically operating up to 10 milling and smelter operations from approximately 1870 through 1940. It is also considered one of the largest U.S. EPA Region 9 CERCLA removal action sites to date. Broadbent was part of the team that addressed overall mining impacts by providing site-wide technical and engineering project management and technical field support services to the EPA. Specific services included: site assessment sampling and analysis at over 300 properties, preparation of an Engineering Evaluation/Cost Analysis (EE/CA), community involvement and reporting, preparation of removal action work plans, design of a 30,000 cubic yard waste repository, and National Historic Preservation Act (NHPA) cultural resource surveys, monitoring, and reporting. Over 5,000 site assessment samples were collected, and over 150 properties were remediated to reduce human-health and environment threats from lead and arsenic contamination. Local community, county, and state feedback was positive, and the project was completed in 2019.
Hillside cap, slag pile removal, and waste repository for Eureka, NV smelter removal and mitigation.