*2.5. Statistical Analysis of Water Quality Parameters Data*

The seven water quality parameters (NH<sup>+</sup> <sup>4</sup> , NO<sup>−</sup> <sup>3</sup> , NO<sup>−</sup> <sup>2</sup> , DO, DOC, pH, and temperature) were analyzed using analysis of variance (ANOVA) test and Welch's test. Levene's test was employed initially to determine whether the data met the hypothesis of homogeneity of variance. If the result rejected the hypothesis, Welch's test was chosen to analyze the significance of differences in various water quality parameters of the groundwater among different riparian observation wells. Otherwise, the ANOVA test was used. The level of significance was set to *p* < 0.05 for both Welch's test and the ANOVA test.
