(a) Assessments. The Director shall establish and collect from the Regulated Entities such assessments he or she deems necessary to maintain a working capital fund.

(b) Purposes. Assessments collected to maintain the working capital fund shall be used to establish an operating reserve and to provide for the payment of large or multiyear capital and operating expenditures as well as unanticipated expenses.

(c) Remittance of excess assessed funds. At the end of each year for which an assessment under this section is made, the Director shall remit to each Regulated Entity any amount of assessed and collected funds in excess of the amount the Director deems necessary to maintain a working capital fund in the same proportions as paid under the most recent annual assessment.