TY - JOUR
T1 - Occurrence and distribution of hexavalent chromium in groundwater from North Carolina, USA
AU - Coyte, Rachel M.
AU - McKinley, Kristen L.
AU - Jiang, Sheng
AU - Karr, Jonathan
AU - Dwyer, Gary S.
AU - Keyworth, Amy J.
AU - Davis, Christina C.
AU - Kondash, Andrew J.
AU - Vengosh, Avner
N1 - Funding Information:
The authors gratefully acknowledge funding from the National Science Foundation ( EAR-1733637 ). We thank the individuals who welcomed us to their homes, businesses, and places of worship, allowing us to collect the large dataset, as well as Enrico Zorzetto for technical assistance. We thank three anonymous reviewers for their thorough and constructive review that greatly improved the quality of this study. Appendix A
Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2020/4/1
Y1 - 2020/4/1
N2 - Hexavalent chromium (Cr(VI)) is a groundwater contaminant that is potentially harmful to human health. Understanding the occurrence of Cr(VI) in groundwater resources is critical for evaluating its risks to human health. Here we report a large dataset (n = 1362) of Cr(VI) and total chromium (CrT) concentrations in public, private, and monitoring wells from different aquifers across North Carolina. These water quality data come from new and previous measurements conducted at Duke University, as well as data reported by the U.S. Environmental Protection Agency, the N.C. Department of Environmental Quality, and the U.S. Geological Survey. The data confirm that Cr(VI) is the predominant species of dissolved Cr and that groundwater from aquifers in the Piedmont region contain significantly higher concentrations than groundwater from the coastal plain. Though there is only one exceedance of the U.S. EPA Maximum Contaminant Level (100 µg/L for CrT) in the dataset, over half of all wells measured for Cr(VI) (470 out of 865) in the dataset exceeded the N.C. Health Advisory Level of 0.07 µg/L. Using information from this dataset, we explore three different approaches to predicting Cr(VI) in groundwater: (1) CrT concentrations as a proxy for Cr(VI); (2) Exceedance probabilities of health goals for groundwater from aquifers located in specific geologic areas; and (3) Censored linear regression using commonly measured field parameters (pH, electrical conductivity, dissolved oxygen) with relationships to Cr(VI) as regressors. Combining these approaches, we have identified several areas in the Piedmont region where Cr(VI) in drinking water wells is expected to be higher than the advisory level, which coincide with large population groundwater reliant populations. While this study focuses on N.C., the wide-spread occurrence of Cr(VI) in groundwater at concentrations above health guidelines in aquifers of the Piedmont region could pose high human health risks to large populations in the eastern U.S.
AB - Hexavalent chromium (Cr(VI)) is a groundwater contaminant that is potentially harmful to human health. Understanding the occurrence of Cr(VI) in groundwater resources is critical for evaluating its risks to human health. Here we report a large dataset (n = 1362) of Cr(VI) and total chromium (CrT) concentrations in public, private, and monitoring wells from different aquifers across North Carolina. These water quality data come from new and previous measurements conducted at Duke University, as well as data reported by the U.S. Environmental Protection Agency, the N.C. Department of Environmental Quality, and the U.S. Geological Survey. The data confirm that Cr(VI) is the predominant species of dissolved Cr and that groundwater from aquifers in the Piedmont region contain significantly higher concentrations than groundwater from the coastal plain. Though there is only one exceedance of the U.S. EPA Maximum Contaminant Level (100 µg/L for CrT) in the dataset, over half of all wells measured for Cr(VI) (470 out of 865) in the dataset exceeded the N.C. Health Advisory Level of 0.07 µg/L. Using information from this dataset, we explore three different approaches to predicting Cr(VI) in groundwater: (1) CrT concentrations as a proxy for Cr(VI); (2) Exceedance probabilities of health goals for groundwater from aquifers located in specific geologic areas; and (3) Censored linear regression using commonly measured field parameters (pH, electrical conductivity, dissolved oxygen) with relationships to Cr(VI) as regressors. Combining these approaches, we have identified several areas in the Piedmont region where Cr(VI) in drinking water wells is expected to be higher than the advisory level, which coincide with large population groundwater reliant populations. While this study focuses on N.C., the wide-spread occurrence of Cr(VI) in groundwater at concentrations above health guidelines in aquifers of the Piedmont region could pose high human health risks to large populations in the eastern U.S.
KW - Geogenic Contaminants
KW - Hexavalent Chromium
KW - Oxyanion
KW - Piedmont
KW - Tobit Regression
KW - Water Quality
UR - http://www.scopus.com/inward/record.url?scp=85076621754&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2019.135135
DO - 10.1016/j.scitotenv.2019.135135
M3 - Article
C2 - 32000345
AN - SCOPUS:85076621754
VL - 711
JO - Science of the Total Environment
JF - Science of the Total Environment
SN - 0048-9697
M1 - 135135
ER -
