|(a) A participating department is liable for the payment of an interest charge if the correction of an error results in the enrollment of, or the crediting of qualified service to, a member who previously was entitled to be enrolled or granted credit for qualified service and the error was the omission of the participating department and not the pension system. (b) An interest charge assessed under this section is calculated on the amount of local contributions due because of the correction of the error and based on the pension system's assumed rate of return as recommended by the actuary, adopted by the State Board of Trustees, and in effect on the date the correction is made, and is compounded annually. The charge is assessed from the date the local contributions would have been made except for the error to the date the correction is made. (c) An interest charge assessed under this section becomes payable with the first quarterly payment that becomes due after the date of assessment. This section does not apply to an error corrected before October 1, 2009.