No severance tax may be imposed on coal used primarily for heating buildings in this state, including the heating of buildings with steam created by the burning of coal, nor may any severance tax be imposed on coal used by the state or any political subdivision of the state. The coal mine owner or operator shall require the person purchasing the coal for heating of buildings, for resale to consumers for heating of buildings, or for use by the state or any political subdivision of the state to certify the amount of the coal purchased which will be used for heating purposes or by the state or any political subdivision.
N.D.C.C. § 57-61-01.1