Mining activities have influenced the environment of Public Lands throughout the West. Tailings from ore mills have contributed large amounts of heavy metals into air, water, stream sediments, and soils. Uncontrolled migration of metal-laden mine tailings via dust entrainment and erosion continues to present potentially adverse risks to human health and wildlife. Recreational demands are increasing on areas where acute and prolonged exposure to relatively high metal concentrations in soils, sediments, and surface waters is occurring. In some locations, avian and aquatic kills have been reported.
To address these issues, BLM has developed acceptable multimedia criteria for the chemicals of concern (heavy metals) as they relate to recreational use and wildlife habitat on BLM lands. The primary objective of this report is to establish risk management criteria (RMC) for human health and wildlife. Risk management criteria provide numerical action levels for metals in environmental media. RMC are designed (1) to assist land managers in making natural resource decisions and (2) to support ecosystem management. Ecosystem management is defined as the skillful use of ecological, economic, social, and managerial principles in managing ecosystems to produce, restore, or sustain ecosystem integrity and desired conditions, uses, products, or values and services over the long term.