Section R. 408.10916 - Gravity, suction, and pressure tanksRule 916.
(1) A gravity or suction water tank shall be maintained at the full water level designed for fire protection purposes.(2) The water and air in a pressure water tank shall be maintained at the designed levels and pressures.(3) The water in a gravity, suction, or pressure tank and risers shall be maintained above freezing temperature. Where a heater is used, the water temperatures shall be not more than 60 degrees Fahrenheit.(4) A steel water tank shall be inspected not less than every 3 years for deterioration and, when necessary, repairs made.(5) A wooden water tank shall be inspected not less than every 2 years for deterioration and, when necessary, repairs made.Mich. Admin. Code R. 408.10916