MI HB4820

Requires persons storing petroleum coke (pet coke) for transport or shipment to obtain a storm water discharge permit.

Mandates that pet coke storage piles and transfer locations be maintained in completely enclosed structures with roofed and walled construction.

Requires entrance and exit points to enclosed storage to have overlapping flaps, sliding doors, or department-approved devices that remain closed except when material or vehicles enter/exit or individuals are inside.

Prohibits surface accumulation of pet coke material (defined as more than 3 ounces per square foot) unless the material is moist, is dry material not higher than 3 inches, or is completely covered.

Directs the department to issue compliance orders within 45 days of the law's effective date, establishing schedules for full compliance with storage requirements by 180 days after enactment, including monitoring and reporting of pile sizes.