In this chapter, the following terms have the meanings indicated. Terms Defined. “Act” means Environment Article, §§15-801—15-834, Annotated Code of Maryland. “Angle of repose” means the maximum angle of slope (measured from a horizontal plane) at which loose cohesionless material will come to rest on a pile of similar material. “Applicant” means that person making application to the Department under the Act for a license or a permit and who is responsible for fulfilling the requirements of the Act, all license and permit conditions, and regulations adopted under the Act. “Backfill” means earth overburden, mine waste, or imported material used to replace material removed during mining. “Bench” means a flat surface from which a pit or quarry is worked. “Critical gradient” means the maximum stable inclination of an unsupported slope. “Cut slope or face” means a bank or slope that is created by removing material below the existing ground surface. “Department” means the Department of the Environment. “Diversion” means a channel, embankment, or other man-made structure constructed for the purpose of redirecting water from one area to another, including interceptor swales, perimeter dikes, and earth dikes. “Erosion” means the process by which the land surface is worn away by the action of water, wind, ice, or gravity. “Excavation” means the extraction or removal of minerals so as to make them suitable for sale, exchange, commercial, or industrial use. “Fill slope” means a bank or slope that has been created by the placing of material on top of the existing ground surface. “Final grade” means the finished elevation of any excavated surface disturbance before replacement of topsoil. “Grading” means to bring an existing surface to a designed form by cutting, filling, or smoothing operations. “Ground water” means subsurface water that fills available openings in rock or soil material such that they may be considered water saturated. Haul Road. “Haul road” means a road that is constructed or used in surface mining and reclamation operations, including one used by vehicles leading to transfer, processing, or storage areas. “Haul road” does not mean a road maintained with public funds. “Highwall” means a site of a pit or quarry adjacent to unmined land. “Impoundment” means a closed basin naturally formed or man-made for the retention of water, sediment, or waste. “License” means the annual written certification from the Department that the licensee is authorized to conduct surface mining activities in the State. “Mined lands” means the surface or subsurface of an area in which surface mining operations will be, are being, or have been conducted. Mined lands include: Private ways and roads used for mining appurtenant to any surface mining area; Land excavations; Workings; and Overburden. “Mine waste” means the residual soil, rock, mineral, liquid, vegetation, equipment, machines, tools, or other materials or property directly resulting from, used in, or displaced by, surface mining operations. “Peak particle velocity” means the maximum velocity of a particle (rate of movement of the ground) in inches per second as measured by the three mutually perpendicular components of motion in the ground immediately adjacent to a structure of concern. “Permit” means the written authorization to mine a particular site, including all conditions, maps, plans, and other supporting documents made a part of the permit that the Department issues to a permittee under the Act. “Processing plant” means any equipment, buildings, structures, or appurtenances used to process non-coal minerals, including crushers, shakers, screens, washers, conveyor belts, settling ponds, and stockpiles of processed materials, and the land upon which these are located. “Sediment” means soils or other surficial materials transported or deposited by the action of wind, water, ice, or gravity as a product of erosion, or by artificial means. “Sediment pond” means any natural or artificial structure or depression used to remove sediment from water and store sediment, including, for example, sediment basins and traps. “Setback” means the distance from a property line, road, or other limiting feature, to an excavation or to the toe of a fill which serves to protect property, a road, or other features. “Stabilization” means methods used to control movement of soil, spoil piles, or areas of disturbed earth and includes any combination of the following: Increasing bearing capacity; Draining; Revegetating; Mulching; Liming; and Fertilizing. “Subsoil” means the part of the soil profile below the topsoil and is sometimes called overburden. “Surface water” means water either flowing or standing on the surface of the earth. “Topsoil” means the upper part of the soil profile that is rich in humus, also known as the A horizon.