(a) Mine facilities. Within 120 days after acknowledgment of completion of mining activities, or if final restoration of the mine area aquifers is required, upon completion of final restoration, the permittee shall accomplish closure of the mining facilities in accordance with approved plugging and abandonment plans submitted as part of the supplementary technical report. An extension of time limit past 120 days must be approved in writing by the executive director.(b) Acknowledgment of closure. When closure has been accomplished, the permittee shall notify the executive director. The executive director will conduct a final inspection of the site to certify that closure has been accomplished in accordance with the permit terms. If closure is certified by the executive director, he shall issue written acknowledgment and permit cancellation procedures will be initiated.