In Covington County, an election official who works at polling places shall receive an additional expense allowance in an amount as will, together with any amount paid by the state pursuant to Section 17-6-13, make the total amount paid to each returning officer and each clerk ninety dollars ($90) for each day the returning officer and clerk work at the polls during any election. Notwithstanding the foregoing, the county commission, from time to time and upon unanimous adoption of a resolution, may increase the amount of the expense allowance provided for in this section.