Any civil penalty assessed pursuant to this chapter shall be payable to the Department, shall be in addition to any other penalty or tax that may be imposed as provided in this chapter, and shall be collectible by the Commissioner in the same manner as if it were part of the tax levied. The amount of any civil penalty imposed under this chapter shall bear interest at the rate of one percent per month until paid. All civil penalties imposed under this chapter shall be deposited as provided in § 58.1-2299.20. Notwithstanding any other provisions of this chapter, the Commissioner is authorized to reduce or waive any civil penalties under this chapter if the violation is due to a reasonable or good cause shown to the satisfaction of the Commissioner.