§ 33.212. Changes and additions.

 (a)  Every three months during construction the owner, contractor or superintendent of each cavern shall place or cause to be placed on the map or plan of the cavern deposited with the Department the plan of the extensions made in the cavern during the preceding year. These extensions shall be placed on the map or plan and a blueprint or copy of the map or plan returned to the Department within 2 months from the date of the last survey.

 (b)  When any cavern is completed or when any level or lift of any cavern is about to be abandoned, the owner, contractor or superintendent of the cavern shall either have the maps or plans extended to include all excavations, as far as practicable and all portions of excavation, as have been worked to the boundary lines of adjoining properties, or have any part surveyed in duplicate and these surveys shall practically agree, and certified copies shall be filed with the Department.