Mich. Admin. Code R. 29.5661
Rule 661. Section 21.7.4.1 of the FL/CL code is adopted with the following changes: 21.7.4.1 Closure of aboveground storage tanks. An owner or operator shall close tanks that have not been used for more than 12 months. To permanently close an aboveground storage tank that is no longer needed to store regulated substance, the owner or operator shall notify the department, not less than 30 days before the intended closure, on form BFS 3858 provided by the bureau. To permanently close an aboveground storage tank, the owner or operator shall empty and clean the tank of all liquid and sludge, render it vapor-free, and safeguard it against trespassing. Piping that is permanently removed from service shall be emptied of all liquids and sludge, be purged and capped, or be removed from the ground.
Mich. Admin. Code R. 29.5661