Coal mine drainage effluents and associated solids major, trace, rare earth element and radium concentrations collected from Pennsylvania, USA

Discharges from abandoned coal mines and associated mine wastes represent historic and persistent sources of pollution in the Appalachian Basin, United States. In this study, we conducted the first-ever survey of radium (Ra) in coal mine drainage (CMD) water and solid samples in the United States. Samples were collected from 4 untreated coal mine discharges and 9 treated coal mine discharges (i.e., passive or active treatment systems in place) in Pennsylvania, representing both bituminous and anthracite coal regions. Dissolved Ra in CMD is relatively low (below detection to 2.06 Bq/L); however, Ra accumulates in associated CMD solids (12.6 to 875.1 Bq/kg). Total rare earth element (REE) + yttrium (Y) content in the CMD solids was enriched with a concentration range of 95.34 to 3,607.15 mg/kg.