Mich. Comp. Laws § 324.9502: Prohibition of discharges into water.

Sec. 9502.

A person shall not place, throw, deposit, discharge, or cause to be discharged into or onto the waters of this state, any litter, sewage, oil, or other liquid or solid materials that render the water unsightly, noxious, or otherwise unwholesome so as to be detrimental to the public health or welfare or to the enjoyment of the water for recreational purposes.

A person shall not discharge, dump, throw, or deposit garbage, litter, sewage, or oil from a recreational, domestic, or foreign watercraft used for pleasure or for the purpose of carrying passengers, cargo, or otherwise engaged in commerce on the waters of this state.