Legacy Mine Hazards

The Sierra Nevada is riddled with abandoned gold mines. Residents and visitors can be unknowingly exposed to physical and chemical hazards while recreating or living on abandoned mine lands (AMLs) in the region. The Sierra Fund educates people in impacted communities about how to protect themselves from exposure to these hazards and supports public policies to ensure appropriate remediation and development of AMLs that underlay the towns and forests of the Gold Country.

For over 100 years cities, parks and schools were built on top of AMLs. Soil tests conducted on AMLs in the Gold Country have found high levels of toxics such as lead, arsenic and asbestos. This problem gets larger as formerly remote AMLs are increasingly in the path of development or are considered for conservation acquisitions. Residents need accessible and understandable information about these threats. Public agencies need to take action to identify and remediate the legacy mine hazards on AMLs in order to protect public and ecosystem health.

Dirtbikers in the Sierra Nevada

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AMLs are found throughout the west including the Coast Ranges, the desert, and the “Gold Country” of the Sierra Nevada. There are an estimated 47,000 abandoned mine features in California almost all with physical hazards and many with chemical hazards. Arsenic, lead, and asbestos co-occur with gold in the Sierra, and along with billions of tons of rock these materials were excavated, crushed, and widely distributed during the Gold Rush. When disturbed this toxic dust can be inhaled during activities such as construction, or during recreational activities.

The Sierra Fund’s Vision for reducing community exposure to legacy mining toxics

The Sierra Fund empowers decision-makers and community members to prevent exposure to legacy mining toxics and to remediate AMLs. Given the nearly invisible nature of legacy chemical and physical hazards, using “due diligence” when taking AMLs through the process of acquisition, and development is crucial to protect the public. The Sierra Fund uses two strategies to achieve this objective:

Community Education on Dusty Exposure

The Sierra Fund’s Gold Country Recreational Trails Assessment and Abandoned Mines Assessment in 2009 provided information on the potential for exposure to mining toxics from dusty activities such as dirt biking, riding horses, and running. Soil samples were taken from popular public trails through mine waste and tested. Based on these results, strategies to reduce health risks at specific locations were identified.

Since that time The Sierra Fund staff have developed protective measures for people recreating, living or working on mine-impacted landscapes. Outreach materials that explain steps to reduce exposure potential have been developed. The Sierra Fund has reached out and made presentations to service providers and recreation groups to educate them about these dangers.

Due Diligence on AMLs

Governments and nonprofit groups alike have used public funds to acquire AMLs without recognizing the hazards created by the land’s historical use. Using “due diligence” (such as soil and water testing and historical research) when taking AMLs through the process of acquisition and development identifies hazards and improves protection of the public from legacy mining hazards.

The Sierra Fund’s Due Diligence in the Gold Country project complements government efforts to increase the pace and scale of remediation of dangerous abandoned mines. Carefully done, targeted conservation acquisitions could increase the pace of remediation of these sometimes startlingly beautiful AMLs. By following appropriate protocols when acquiring AMLs

  • Conservation of critical habitats and landscapes can be facilitated
  • Liability for environmental and physical hazards can be clarified
  • Appropriate end-use(s) can be identified
  • Remediation actions can be incentivized and pursued.