Asphalt means a dark brown to black cement-like material (solid, semisolid, or liquid in consistency) in which the predominating constituents are bitumens which occur in nature as such or which are obtained as residue in refining petroleum.
Diameter at Breast Height (DBH) means the diameter of the trunk of a mature tree generally measured at a point four and a half feet above ground level from the uphill side of the tree. For species of trees where the main trunk divides below the 4 ½ foot height, the DBH shall be measured at the highest point before any division.
Tight-fitting facepiece means a respiratory inlet covering that forms a complete seal with the face.
Basement means any area of the building having its floor subgrade (below ground level) on all sides.
Uppermost aquifer means the geologic formation nearest the natural ground surface that is an aquifer, as well as lower aquifers that are hydraulically interconnected with this aquifer within the facility's property boundary.