In Jefferson County, where the chief clerk of the probate court appointed pursuant to Section 12-13-40, is also serving in a civil service position with the probate court, the chief clerk shall receive a salary in the sum of twenty thousand dollars ($20,000) per year for the appointed position. The salary shall be paid from the general fund of the county in equal monthly installments and shall be in addition to any other salary, allowances, or benefits the chief clerk receives, now or in the future, by virtue of holding a civil service position with the probate court.