Abandonment shall be approved by the Secretary after restoration of the drill site and its subsurface has been accomplished in conformity with the following requirements:
(A) The derrick and all appurtenant equipment thereto shall be removed from the drill site;
(B) All tanks, towers and other surface installations shall be removed from the drill site;
(C) All concrete, pipe, wood and other foreign materials shall be removed from the drill site to a depth of six feet below grade unless they constitute a part of a multi-well cellar being used in connection with any other well for which a permit has been issued;
(D) The oil well casing shall be cut off at the bottom of the cellar or, if there is no cellar, five feet below the drill site grade at the cellar. Nothing shall be placed in the excavation above the point of cut-off until the cut-off has been inspected by the Secretary and found to comply with all applicable provisions of law;
(E) The top 25 feet of the remaining casing shall be filled with a cement plug to prevent gas fumes from escaping;
(F) A steel cap of not less than the same thickness of the casing shall be welded to the casing around the entire circumference of the well casing;
(G) All holes and depressions shall be filled and compacted to 90% with native earth. All oil, waste oil, refuse or waste material shall be removed from the drill site.
(`78 Code, § 14.28.040.)