Statewide Mercury TMDL Information

Water bodies are impacted by atmospheric deposition of mercury throughout the state.  Mercury is a metal that occurs naturally in the environment.  Major uses of mercury in the United States include lighting, switches, instruments, the dental industry, laboratory uses, and other industrial applications.  Local and global anthropogenic activities such as mining, coal combustion, and industrial uses have release mercury in excess of pre-industrial period concentrations.

The DEQ developed the statewide TMDL as required under Section 303(d) of the federal Clean Water Act (CWA).  The federal CWA requires a TMDL to be written for water bodies not meeting Michigan's water quality standards.  The purpose of the TMDL is to gather data, identify sources, and develop appropriate goals and reasonable assurance that will restore the designated uses to the water bodies.

Statewide Mercury TMDL