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AML Inventory

A System-wide National Park Service (NPS) inventory and assessment of its Abandoned Mineral Lands (AML) was started in fiscal year (FY) 2010 to address two primary objectives:

  • Categorize high, medium, and low priority mitigation needs for NPS AML features according to human hazard and environmental criteria, and;
  • Estimate the resources needed to address priority issues with NPS AML features.

By addressing these two main objectives, this project demonstrates responsiveness to key issues raised by the Office of the Inspector General (OIG) in its July 2008, OIG Audit Report: Abandoned Mine Lands in the Department of the Interior (DOI 2008). It also responds to the NPS Director's October 2, 2008, memorandum, which, in response to the OIG audit, directed regional and associate directors to update the NPS AML inventory and to identify the funding needed to address priority NPS AML features.

National Park System Units with Abandoned Mineral Lands

map Pacific West Region Pacific West Region Intermountain Region Midwest Region Southeast Region Northeast Region National Capitol Region Alaska Region * click on map to view Regional Summaries

To date, 23,182 AML features have been identified in 129 of the 399 units that make up the
National Park System. The inventory effort is completed in all except the California NPS units. NPS
believes that when the inventory effort is completed by the end of 2013, approximately 80% of the
documented AML features will be located in the Pacific West Region's California parks, however, all
seven NPS regions have significant AML features and issues. Commodities extracted vary regionally but generally include precious metals, base metals, and industrial minerals in the Alaska, Intermountain, and Pacific West Regions; uranium, oil, and gas in the Intermountain Region; and coal, oil, and gas in the Midwest, Northeast, and Southeast Regions. All regions have sand, gravel, and rock quarries. AML features are vestiges of a time when reclamation was not required by federal and state laws and policies, and many pose serious safety issues and resource impacts. Of the 23,182 features inventoried, 1,341 (5.8%) have already received final remedial action, 2,869 (12.4%) are in need of treatment, and the remainder have been inventoried to assist in fully characterizing each site.

The total cost for remediation of the 2,689 AML features that require action is approximately $55.6 million. There are 2,435 features in the high priority category that will cost approximately $44.9 million to remediate. Medium priority sites include 218 features that will cost approximately $7.5 million to remediate. Low priority sites include 216 features that will cost approximately $3.2 million to remediate.

AML Inventory and Assessment Interim Products

Report cover 2013 Interim Report

The NPS is issuing this interim report to use the information gathered to-date for current AML remediation planning needs. The NPS is undertaking the inventory of its California units under a separate effort not scheduled to be complete until late 2013. The current California parks inventory is just over 50% complete, and includes 14,428 features, 2,869 of which require mitigation at an estimated cost of $10.2 million. Those data are included in this report. Completion of the California effort in 2013 will add additional features and costs to the inventory. A final report incorporating complete NPS AML inventory data will be completed in early 2014.
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Summary tableInventory by Park and Region

Service-wide summary of AML sites and features compiled November, 2012.

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abandoned mine shaft

Regional Summaries

Learn about regional differences regarding AML issues.

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Last Updated: April 23, 2013