title: Isotopic imprints of mountaintop mining contaminants.
abstract: Mountaintop mining (MTM) is the primary procedure for surface coal exploration within the central Appalachian region of the eastern United States, and it is known to contaminate streams in local watersheds. In this study, we measured the chemical and isotopic compositions of water samples from MTM-impacted tributaries and streams in the Mud River watershed in West Virginia. We systematically document the isotopic compositions of three major constituents: sulfur isotopes in sulfate (δ(34)SSO4), carbon isotopes in dissolved inorganic carbon (δ(13)CDIC), and strontium isotopes ((87)Sr/(86)Sr). The data show that δ(34)SSO4, δ(13)CDIC, Sr/Ca, and (87)Sr/(86)Sr measured in saline- and selenium-rich MTM impacted tributaries are distinguishable from those of the surface water upstream of mining impacts. These tracers can therefore be used to delineate and quantify the impact of MTM in watersheds. High Sr/Ca and low (87)Sr/(86)Sr characterize tributaries that originated from active MTM areas, while tributaries from reclaimed MTM areas had low Sr/Ca and high (87)Sr/(86)Sr. Leaching experiments of rocks from the watershed show that pyrite oxidation and carbonate dissolution control the solute chemistry with distinct (87)Sr/(86)Sr ratios characterizing different rock sources. We propose that MTM operations that access the deeper Kanawha Formation generate residual mined rocks in valley fills from which effluents with distinctive (87)Sr/(86)Sr and Sr/Ca imprints affect the quality of the Appalachian watersheds.
authors.affiliation: Division of Earth and Ocean Sciences, Nicholas School of the Environment, Duke University , Durham, North Carolina 27708, United States. vengosh@duke.edu
authors.forename: Avner
authors.initials: A
authors.lastname: Vengosh
authors.forename: T Ty
authors.initials: TT
authors.lastname: Lindberg
authors.forename: Brittany R
authors.initials: BR
authors.lastname: Merola
authors.forename: Laura
authors.initials: L
authors.lastname: Ruhl
authors.forename: Nathaniel R
authors.initials: NR
authors.lastname: Warner
authors.forename: Alissa
authors.initials: A
authors.lastname: White
authors.forename: Gary S
authors.initials: GS
authors.lastname: Dwyer
authors.forename: Richard T
authors.initials: RT
authors.lastname: Di Giulio
mesh_terms: D017554:Carbon Compounds, Inorganic / Q000032:analysis*; D002247:Carbon Isotopes / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods*; D019015:Geologic Sediments / Q000032:analysis; D008906:Mining; D045483:Rivers / Q000737:chemistry*; D012643:Selenium / Q000032:analysis; D013324:Strontium / Q000032:analysis*; D013325:Strontium Isotopes / Q000032:analysis; D013431:Sulfates / Q000032:analysis*; D013460:Sulfur Isotopes / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014903:West Virginia
chemical_list: D017554:Carbon Compounds, Inorganic; D002247:Carbon Isotopes; D013325:Strontium Isotopes; D013431:Sulfates; D013460:Sulfur Isotopes; D014874:Water Pollutants, Chemical; D012643:Selenium; D013324:Strontium