Acid drainage
Acid drainage means water with a pH of less than 6.0 and in which total acidity exceeds total alkalinity, discharged from an active, inactive or abandoned surface coal mine and reclamation operation or from an area affected by surface coal mining and reclamation operations.
Source
30 CFR § 701.5
Scoping language
As used in this chapter, the following terms have the specified meanings, except where otherwise indicated: