Sand and Gravel Excavation Act Article 26

When the sand and gravel in a sand and gravel excavation area is depleted or the sand and gravel excavator has no intention of continuing operations, the excavator shall carry out site rehabilitation in accordance with the originally approved sand and gravel excavation plan and drawings and relevant laws and regulations, and subsequently surrender the Sand and Gravel Excavation Permit Certificate and the Sand and Gravel Excavation Field Registration Certificate to the Competent Authority of the Special Municipality or County (City) for cancellation; if the excavator fails to surrender them, the Competent Authority of the Special Municipality or County (City) shall cancel them on its own initiative.
中文原文 土石採取法第26條
土石採取人於土石採取區之土石採罄或無繼續經營意願時,應依原核定之土石採取計畫書圖及相關法令規定辦理整復後,向直轄市、縣(市)主管機關繳銷土石採取許可證及土石採取場登記證;其未繳銷者,由直轄市、縣(市)主管機關註銷之。

English translation for reference only; the Chinese text prevails. Not legal advice.