(1) The tax levied by this part shall be due and payable monthly on the first day of the month next succeeding the month in which the coal is severed from the soil.
(2) For the purpose of ascertaining the amount of tax payable, it is the duty of all operators to transmit to the commissioner, on or before the fifteenth day of the month next succeeding the month in which the tax accrues, a return upon forms provided by the commissioner.
(3) A separate return shall be filed for each county from which coal is severed showing the month or period covered, the total number of tons of all coal products severed from each production unit operated, owned or controlled by the taxpayer during the period covered, the county in which produced, the amount of the tax, and such other information as the commissioner may require.
(4) A copy of such separate return shall also be sent by the operator to the county trustee of the county from which the coal is severed.
(5) The return shall be accompanied by a remittance covering the amount of tax due as computed by the taxpayer.