CO₂ Leakage-Induced Contamination in Shallow Potable Aquifer and Associated Health Risk Assessment

Figure 9

(a) Changes in pH, total arsenic (As), and arsenite () concentrations monitored at the municipal well. The maximum contaminant level (MCL) of arsenic species is 1.33 × 10⁻⁷ mol/L. Gaseous CO₂ saturation () and pH for 10 years were also plotted at the magnified window. Two stages were characterized based on the behavior of CO₂ plume. (b) Frequency of predicted health risk accounting for both As and and cumulative density functions representing probabilistic health risk. The bin size of both histograms was designated to be 10⁻⁴, and thus the number of bins was 10 and 20, respectively. Finally, the threshold of risk or the risk level of concern was 10⁻⁴ (red dotted line).

(a)

(b)