Governing Law and Regulations
Michigan Department of Natural Resources and Environment (DNRE) Water Resource Division
U.S. Environmental Protection Agency (EPA) Region 5
See ADDRESSES & CONTACTS for addresses and telephone numbers.
See national section for basic information and federal regulations.
Comparison: State vs. Federal
• Rules. Michigan has established specific effluent guidelines for temperature as part of the NPDES permitting system. Wastewaters discharged in Michigan must meet specific temperature requirements which are specific to water bodies and regions of the state.
• Administration and enforcement. DNRE's Water Resource Division is responsible for the administration and enforcement of the state's thermal discharge regulations.
MAC r. 323.1069
In all waters of the state, temperature measurement is usually taken within 1 meter of the surface, unless measurement at a deeper depth is required. While monthly maximum temperatures may be excluded for short periods, these increases can never be more than the natural water temperature plus the increase allowed at the edge of the mixing zone. Generally, all efforts have to be made to maintain the natural daily and seasonal temperature fluctuations of the receiving waters. The waters of the state have been separated by type and location, with thermal standards set for specific regions and water bodies.