As described by ASTM D7780-12: This feature class contains polygons that depict the location of coal refuse disposal areas. They include, but are not limited to, slurry impoundments (including cross valley, diked, and incised impoundments), slurry cell structures, and coarse coal refuse structures. This dataset consists of coalmining related features as described by ASTM D7780-12, "Standard Practice for Geospatial Data for Representing Coal Mining Features". These data are gathered using automated processes from participating coalmining regulatory authorities, which are generally state government agencies. The data from the various sources are transformed into common schemas as described by the ASTM Standard above. The resultant feature classes represent seamless information covering the coal producing areas of the United States. Development of these data are ongoing and will become more complete as more cooperating regulatory authorities are added to the GeoMine system.