Johnson Crystal D, Nandi Arpita, Joyner T Andrew, Luffman Ingrid
Department of Geosciences, College of Arts and Sciences, East Tennessee State University, Johnson City, TN, 37614.
Ground Water. 2018 Jan;56(1):87-95. doi: 10.1111/gwat.12560. Epub 2017 Aug 1.
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.
出于健康、经济和美观的原因，美国环境保护局建议饮用水中二级污染物铁（Fe）和锰（Mn）的允许浓度分别为0.3毫克/升和0.05毫克/升。从北卡罗来纳州本康伯县农村社区的私人饮用水井采集的水样中，这些金属的浓度超过了二级水质标准。本研究预测了该县铁和锰的空间分布，并评估了场地环境因素（基岩地质、地面高程、腐泥土厚度和饮用水井深度）对控制地下水中铁和锰变异性的影响。研究发现，由于基岩地质的原因，铁和锰的浓度之间存在统计学上的显著相关性。利用普通克里金法和协同克里金法插值技术创建了预测模型，以估计在无法进行直接测量的情况下地下水中铁和锰的存在情况。同样的程序可用于估计不同地区具有相似水文地质环境的地下水中其他污染物的趋势。
