MERCURY WARS
Mercury “Fate and Transport” Sierra Nevada to SF Bay Delta - illustration
Figure depicts transport of “fugitive” or mercury lost during historic hydraulic mining operations and its transport from Sierran rivers to the San Francisco Bay and Delta region. Also depicted is the chemical transformation of elemental mercury to toxic organic mercury or methyl mercury. Source: US Geological Survey.
public policy and political issues, such as what is the proper role and responsibil- ity of the state and federal government to “cleanup” abandoned mine land sites with “point or non-point” sources of mercury pollution.
Creating practical solutions to remove mercury from the environment will be costly and time consuming, but there is no better time in Sierran history than now to start. Inventors in the recreational mining community can develop new types of equipment that efficiently recover gold but don’t discharge toxic tailings into rivers and streams. Effective removal of mine tailings and associated mercury on a regional scale could take centuries.
Ancient (Early Tertiary Age) Yuba River Map.
The ancient Yuba River system was a major source of placer gold production in the Sierra Nevada region during the 19th century. Source: California Gold Publications.
regarded by them as prima facia evidence that environmental- ists are conspiring to take away their hard-won mining rights.
The use of suction dredges to recover mercury from streams and rivers has been proposed by certain mining groups, but unfortunately, standard suction dredge technology is not designed to recover micron or submicron size mercury par- ticles.
The local mining community has not been supportive of pilot mercury cleanup projects to date. Knowledgeable miners real- ize there could be thousands of sluicebox tunnels that could have discharged mercury into rivers streams and reservoirs. Such miners consider that mercury cleanup projects would be a waste of taxpayer dollars. This speaks to much broader
The sand and gravel industry may be in the best position to extract “fugitive mercury.” Most of the large aggregate producers on Sierran river drainages already reprocess hydraulic and bucket line dredge tailings and “unofficially”
recover significant amounts of mercury previously lost by hydraulic mining operations. However, some aggregate com- panies fear their commercial operations might be restricted or shut down if they had to report their recovery of large amounts of mercury to state regulators.
David Lawler has been a practicing, professional geosci- entist for over 30 years, with domestic and international expertise in lode and placer precious metal deposits. David resides in Grass Valley, CA. He is also regarded as an expert on abandoned mines and environmental issues in California and the western USA region.
www.aipg.org
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