Mercury

 

Nevada Mining and Mercury

 

The Nevada Mining Association wants you to know the facts regarding Nevada gold mines' achievements in controlling mercury emissions.

 

Mercury occurs naturally in soils throughout the country and is a trace element contained in the ores we mine and process in Nevada. Unlike the recovery processes of the 1800s, mercury is no longer used to recover gold and silver. However, some precious metal ores contain recoverable amounts of mercury. Through the same process that produces gold and silver, some mercury is recovered and sold to manufacturers of various important products.  Some gold and silver recovery processes can also cause a release of mercury into the air. Airborne mercury comes from many sources, both natural and anthropogenic (human-caused).   In April of 2006, the Federal Environmental Protection Agency (EPA) said recent emissions estimates of annual global mercury emissions from all sources, natural and anthropogenic (human-generated), which are highly uncertain, are about 4800-8300 tons per year.  This range is consistent with its1997 report to Congress, in which the EPA estimated that the total annual global input to the atmosphere is 5,500 tons of mercury from all sources.  Of this total, the EPA reported the U.S. annual contribution from anthropogenic sources to the annual global total is approximately 158 tons.  For 2004, Nevada Mines reported Toxic Release Inventory air emissions of 2.3 tons.  Using the EPA estimates of 5,500 tons of mercury from all sources in the global atmosphere, Nevada gold mining’s contribution would be about .04% of those mercury emissions. Using EPA’s estimate of approximately 158 tons per year from U.S. anthropogenic sources, Nevada gold mining’s contribution to U.S. man made emissions would be about 1.5%.

 

Nevertheless, the Nevada Mining Association and its members clearly recognize the importance of minimizing mercury in the environment. Nevada’s gold mines have taken aggressive action to reduce their emissions – with impressive results.

 

Nevada mining’s initial mercury air emissions reductions were achieved by four of the largest gold mining companies through their participation in the Voluntary Mercury Reduction Program (VMRP), beginning in 2001. The mining industry worked closely with the Nevada Division of Environmental Protection (NDEP) and EPA’s Region 9 to develop and implement the VMRP. In addition, all gold mining members of the Nevada Mining Association worked together in 2005 on technology transfer and information sharing on methods to further reduce emissions.

 

Nevada’s newest precious metals processing facilities include state-of-the-art controls for mercury emissions. The U.S. EPA considers most of these control technologies consistent with Maximum Achievable Control Technology (MACT) criteria under the Clean Air Act. The VMRP specifically addressed the older facilities – requiring them to add MACT-equivalent equipment or make operating modifications that would reduce mercury emissions by at least 50 percent by the end of 2005. Even greater reductions than the target were achieved far faster than would have been possible under the traditional federal rule making approach. By 2002, participants in the VMRP documented a 40 percent reduction in mercury emissions compared to 1998 levels and a further 35 percent reduction (for a total reduction of 75%) by the end of 2003 – earning the EPA’s “Environmental Heroes Award.”   The estimated reduction in mercury air emissions achieved by VMRP participants through 2004 exceeds 80 percent relative to the 1998 baseline.

 

In October 2005, the NDEP, Nevada’s precious metals mining industry, and the EPA agreed to further enhancements to the mercury air emission reduction program.  The NDEP described this effort in a document entitled “Nevada Mercury Air Emissions Control Program,” in which the agency stated that it “has determined that it is necessary and appropriate to develop measures for the control of mercury emissions from mercury emitting thermal point sources located at precious metals mining operations in Nevada.”
 

On March 8, 2006, the State Environmental Commission (SEC) formalized the program as a regulation pursuant to the commission’s statutory authority in Nevada Revised Statutes (NRS)445B.100 and 445B.235.  The new regulation became effective on May 4, 2006

 

The new program does the following:

·       It replaces and builds upon the success of the VMRP.

·       It complies with federal Clean Air Act requirements[1]and obviates the need for the EPA to pass a federal rule for mercury controls at precious metals mines. 

·       It establishes a very stringent requirement for installation and operation of state-of-the-art mercury emission controls(defined as the Nevada MACT) on all significant mercury sources from all precious metals mines in Nevada.

·       As part of the state’s air quality permitting program, compliance is mandatory and enforceable.

·       The program requires detailed monitoring, testing, record keeping, and reporting to the State.

The Nevada Mining Association and its member companies testified in favor of the SEC’s adoption of the new regulation and look forward to continued success in controlling mercury air emissions from Nevada’s gold production facilities.

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House Resources Committee Report: Fact & Fiction on Mercury 
Exhaustivereviewof the science on mercury (Feb. 16, 2005). The paper is a comprehensive synopsis of the federal agency, private and recently peer-reviewed research used in the debate over regulating mercury Mercury in Perspective: Fact and Fiction About the Debate Over Mercury