Assessment of vulnerability and contamination potential of Ozark Plateau Aquifer in Cherokee County, KS

Abstract

Abstract Access to clean drinking water is essential for public health. However, groundwater contamination by toxic metals like lead (Pb) and zinc (Zn) as well as nitrate poses a significant threat to drinking water supplies, particularly in areas with a history of mining. These metals can cause neurological disorders in children, heart disease, kidney problems, and more. This study investigates the vulnerability of aquifer systems in Cherokee County, Kansas, a former mining district within the Tri-State Mining District, designated as a Superfund site by the US Environmental Protection Agency (EPA) due to environmental degradation. Limited research exists regarding the vulnerability of Cherokee County's aquifers to heavy metal contamination. This study employs the DRASTIC model, a well-established method that considers seven hydrogeological parameters: depth to water table (D), net recharge (R), aquifer media (A), soil media (S), topography (T), impact of the vadose zone (I), and hydraulic conductivity (C) to evaluate aquifer vulnerability. The DRASTIC analysis identified two vulnerability zones within Cherokee County: very low (risk index 31-80) and low vulnerability (risk index 80-120). The very low vulnerability index is primarily concentrated in the southwest and northeast parts of the study area, whereas the low vulnerability index dominates the study area. The model’s model performance assessed using water quality data, which revealed a weak correlation between DRASTIC index and concentrations of lead (R2=0.44) and nitrate (R2=0.46) which suggests the model effectively identified areas where this contaminant is prone to aquifer contamination. The weak correlation for zinc (R2=0.25) highlights the need for integration of additional geochemical and isotopic analysis to confirm contamination sources and enhance accuracy of prediction. This study provides valuable insights into future research and resource management strategies in Cherokee County. By identifying vulnerable areas, these findings can inform land-use planning, pollution prevention measures, and potential remediation efforts, ultimately aiming to protect public health and ensure sustainable groundwater resources. The findings also highlight the broader applicability of the DRASTIC framework for assessing aquifer vulnerability regions facing similar contamination challenges.