• The State of Michigan, Department of Environment, Great Lakes, and Energy commonly receives questions and complaints related to regulation of domestic wastewater discharges to the ground or groundwater of the state. This response applies to:

• Potable water (i.e. water that is safe to drink) used for domestic activities other than sanitary sewage disposal. An example of this is wastewater generated from washing paint brushes used at the home; this does not apply to dumping the unused paint onto the ground.
• Wastewater from a portable power washer when used by the occupant of a household for washing buildings, vehicles, or other surfaces associated with the domestic occupation of the household.
• Residential water treatment filter backwash water.
• Residential swimming pool drainage and backwash water.
• Carpet cleaning wastewater from a single residence discharged by a homeowner or by a commercial carpet cleaning company on the property where the carpet cleaning occurred.
• Wastewater from a residential heat pump that has a heat exchange capacity of 300,000 BTU per hour or less and no chemical additive to the system.
• Stormwater that is not from a secondary containment structure and that is discharged to the ground surface.

These discharges are regulated pursuant to Part 31, Water Resources Protection, of the Natural Resources and Environmental Protection Act (NREPA), Public Act 451 of 1994, as amended and the Part 22 Groundwater Quality Rules. The law and rules provide that a person does not need a permit for the discharge of the above domestic discharges to the ground but also does not waive liability for causing injury to the waters of the state. This means the discharge cannot cause waters of the state (which include groundwater) to lose their usefulness for drinking, agriculture, recreation, industry, or other “protected” uses. To be safely discharged to the ground without a permit, the following conditions must be met:

• The discharge cannot cause physical damage to neighboring properties or create nuisance conditions (i.e., flooding or erosion).
• The discharge cannot create a site of environmental contamination. If a site of environmental contamination is created, the discharger is and remains liable for the cost of cleaning up the contamination.
• Discharges to the ground should not occur if the home is connected to or is within 200 feet of the municipal sanitary sewer. There are some exceptions to this condition if the municipal sanitary sewer has specifically prohibited certain wastewater from being discharged to the sewer. Please contact your local Groundwater Discharge program staff for more information on this condition.