Optional planning period extension.The planning unit may elect to add an additional two years to a planning period and extend their approved LSWMP expiration date two years. The planning unit must submit all the required information identified in section 366-2.5(b) and (c) and sections 366-2.6 and 366-2.7 of this Part governing an additional two year period. A maximum of five two-year planning period extensions may be requested and approved by the department prior to soliciting public comment in accordance with Subpart 366-3 of this Part with respect to the additional planning period extensions and any other adjustments made to the LSWMP, and receive approval in accordance with the procedures outlined in subdivision (c) of this section.