Michigan Water Quality Standards

Contact: Kevin Goodwin, 517-290-4198, or [email protected]

Water Quality Standards are the foundation of the water quality-based pollution control program mandated by the Clean Water Act. Water Quality Standards define the goals for a waterbody by designating its uses, setting criteria to protect those uses, and establishing provisions such as antidegradation policies to protect waterbodies from pollutants.

The State of Michigan’s Part 4 Rules, Water Quality Standards (of Part 31, Water Resources Protection, of Act 451 of 1994), specify water quality standards which shall be met in all waters of the state.

Michigan’s Part 4 Water Quality Standards require that all designated uses of the receiving water be protected.  Designated uses include: agriculture, navigation, industrial water supply, public water supply at the point of water intake, warmwater or coldwater fish, other indigenous aquatic life and wildlife, fish consumption, partial body contact recreation, and total body contact recreation from May 1 to October 31. 

Part 4 Rules

Rule 57 Water Quality Values

The State of Michigan’s Part 8 Rules, Water Quality-Based Effluent Limit Development for Toxic Substances, is used to establish toxic substance water quality-based effluent limits (WQBELs) for point source discharges that are protective of the designated uses of the surface waters of the state. The Part 8 Rules include provisions for establishing Total Maximum Daily Loads (TMDLs), wasteload allocations for toxic substances, reasonable potential for chemical-specific WQBELs, and calculating WQBELs that are less than the quantification level.

Part 8 Rules