A variance is valid for a period of two (2) years from the written Notice of Decision, or the decision on an appeal, whichever is later.

A single one (1) year extension may be granted by the Director prior to the expiration date if the applicant can demonstrate that circumstance or conditions, not known or foreseeable at the time of original application, warrant an extension of the permit. The extension request must be received by the department no later than thirty (30) days prior to the expiration of the permit.