MINING-INFLUENCED REGIONAL SALINIZATION OF APPALACHIAN STREAMS

The salinization of freshwater streams has been increasing in recent times due to many factors including urbanization, agriculture, land use changes, and mining. In the coalfields of Appalachia, surface and underground coal mining increases the salinity of streams in the region as rapidly-weathering mine rocks release elements to streams. Such releases cause an increase in the specific conductance (SC), which is an indicator of increased salinization. In this study, we analyzed water quality data from 4,714 separate stream water quality monitoring stations from Kentucky, Ohio, Pennsylvania, Tennessee, Virginia, and West Virginia. All samples were collected by state agencies between January 1, 2007 and December 31, 2016 from streams with watersheds < 65 km² in counties containing coal mining operations. We used ArcMAP to model concentrations of 10 parameters across the coalfields including: pH, SC, Ca, Mg, Na, K, Cl, S, Al, and Fe. Results indicate widespread salinization of streams across the Appalachian region, with higher SC values modeled near underground and surface coal mine operations. A principal component analysis indicated that SC is linked to Ca, Mg, Na, K and S concentrations in streamwater and that Fe and Al concentrations in streamwater are linked to pH. Overall, results indicate that coal mining operations in the Appalachian region are a contributing factor to freshwater salinization.