Iron and Manganese in Groundwater: Using Kriging and GIS to Locate High Concentrations in Buncombe County, North Carolina

• Published in: Ground water Vol. 56; no. 1; pp. 87 - 95
• Main Authors: Johnson, Crystal D., Nandi, Arpita, Joyner, T. Andrew, Luffman, Ingrid
• Format: Journal Article
• Language: English
• Published: Malden, US Blackwell Publishing Ltd 01.01.2018; Ground Water Publishing Company
• Subjects: Bedrock; Contaminants; Drinking water; Environmental effects; Environmental factors; Environmental protection; Geographical information systems; Geology; Groundwater; Groundwater pollution; Heavy metals; Hydrogeology; Iron; Kriging interpolation; Manganese; Metal concentrations; Metals; Prediction models; Rural areas; Rural communities; Spatial distribution; Statistical analysis; Statistical methods; Water analysis; Water depth; Water quality; Water sampling; Water wells; North Carolina; United States > US
• ISSN: 0017-467X; 1745-6584
• DOI: 10.1111/gwat.12560

For health, economic, and aesthetic reasons, allowable concentrations (as suggested by the United States Environmental Protection Agency) of the secondary contaminants iron (Fe) and manganese (Mn) found present in drinking water are 0.3 and 0.05 mg/L, respectively. Water samples taken from private drinking wells in rural communities within Buncombe County, North Carolina contain concentrations of these metals that exceed secondary water quality criteria. This study predicted the spatial distribution of Fe and Mn in the county, and evaluated the effect of site environmental factors (bedrock geology, ground elevation, saprolite thickness, and drinking water well depth) in controlling the variability of Fe and Mn in groundwater. A statistically significant correlation between Fe and Mn concentrations, attributable to bedrock geology, was identified. Prediction models were created using ordinary kriging and cokriging interpolation techniques to estimate the presence of Fe and Mn in groundwater where direct measurements are not possible. This same procedure can be used to estimate the trend of other contaminants in the groundwater in different areas with similar hydrogeological settings. Article impact statement: Kriging interpolation to predict iron and manganese in groundwater in rural United States, can be used by agencies for groundwater well planning.