To explore the data, see our interactive map of acid-generating mining sites in Canada. The GIS data are also available for download . Background and context on this project is given below.
Acid is generated under certain natural conditions even in the absense of mining.
Mining, however, can greatly exacerbate acid generation. Through the mining process, minerals are broken down, crushed, and ground up, exposing a vastly greater amount of sulphide minerals to air and water than would occur in an undisturbed environment. After the target minerals are extracted from the ore, sulphur-bearing minerals are discarded with the tailings and waste rock. AMD is a concern for two reasons. Second, the acid dissolves metals previously bound up in ore and surrounding rock.