Mercury (Hg)

Contact: Joy Taylor Morgan, 616-824-1352
Agency: Environment, Great Lakes, and Energy

Mercury (chemical symbol Hg) is a heavy, silvery-white metal sometimes called quicksilver. It is the only metal that is liquid at ordinary temperatures and is naturally found in rocks and other environmental media. It has been historically released to the environment by natural events like volcanic eruptions and weathering of minerals. However, human and industrial activities, including those that use mercury directly or burn mercury bearing fossil fuels like coal, have increased the amount of mercury in the environment. Mercury is a persistent, bioaccumulative neurotoxin. Studies indicate an increased risk to a developing fetus upon exposure to methylmercury via maternal fish consumption. Mercury released from anthropogenic (man-made) and natural sources can be deposited in the environment, a portion of which is converted to methylmercury in aquatic systems before finding its way into fish.

EGLE developed new air pollution control rules addressing mercury emissions from coal-fired electric generating units (EGUs), to meet the requirements of Governor Jennifer M. Granholm's directive to reduce mercury emission from coal-fired EGUs. The rules under Part 15 "Emission Limitations and Prohibitions - Mercury," went into effect October 16, 2009.  EGLE also revised the Parts 10 and 11 rules to address necessary changes to the testing/sampling and monitoring protocols.

The Department revised the applicability of the rules in 2013 to be more in line with the Mercury and Air Toxics Standards (MATS). Part 15 will not be in effect as long as MATS is an applicable requirement regulating the emissions of mercury even though there have been legal challenges filed against MATS. However, once all legal challenges against MATS have been resolved which no further appeal or review is taken or available, one of two things will happen:

  1. If the provisions of MATS are upheld, Part 15 will be repealed and voided 60 days after the final judgment or order is issued; or
  2. If the provisions of MATS are struck down, Part 15 will be in force and go into effect three (3) calendar months after the termination of MATS.

Access to all approved rules: Michigan Air Pollution Control Rules.

Reports and Other Information

On January 30, 2008, a team of MDEQ staff from the air, water, pollution prevention, and remediation programs, called the MDEQ Mercury Strategy Workgroup (MSWG), released their report entitled, MDEQ Mercury Strategy Staff Report along with its Appendices. The "MSWG Staff Report" was drafted in response to a charge from MDEQ Director to develop a strategy that eliminates anthropogenic or human mercury use and release to Michigan's environment. This comprehensive mercury report includes 67 recommendations, along with the workgroup's top ten priority actions identified. The desired outcome is to make Michigan's fish safe to eat. Getting there involves working cooperatively with a multitude of stakeholders. A copy of the MSWG Strategy's Executive Summary, which includes the 67 recommendations, is also available.

Additional Mercury Information

What EGLE and Others Are Doing