Requests for extensions under the act shall be in writing. Extensions will be granted only by a written extension document. Extensions granted under the act shall only be on a quarterly (3 month) basis and shall be for 3, 6, 9 or 12 months, except as provided in WAC 332-140-050 (2)(c). An extension will not be granted for less time than is reasonably required, as determined by the department, to remove all of the forest products remaining on the sale being extended.