1. “Excavation” means the movement or removal of earth, rock or other material in or on the ground by:
(a) Use of mechanical equipment;
(b) Use of non-mechanical equipment by:
(1) A contractor; or
(2) Any person, other than a contractor, if at any point the movement or removal of such material occurs more than 12 inches below the surface of the original groundline; or
(c) The placement and discharge of explosives.
2. The term includes augering, backfilling, boring, digging, ditching, drilling, grading, plowing-in, ripping, scraping, trenching and tunneling.