**4. Water quality index**

Water quality was identified based on the water quality index (WQI) [41].

$$\text{WQI} = \mathbf{100} - \sqrt{\left(\mathbf{F}\_1^2 + \mathbf{F}\_2^2 + \mathbf{F}\_3^2\right)} / \mathbf{1.73}$$

Where,

F1 **=** [Water variables that do not meet objectives/Total number of water variables]\*100 F2 **=** [Number of tests that do not meet objectives/Total number of tests]\*100 F3 = nse/0.01 nse + 0.01

### Where,

nse (normalized sum of excursions) = Σ<sup>n</sup> departure/number of tests.

The variables that do not meet objectives are those parameters that exceed the WHO permissible limits. At the same time, the number of tests that do not meet objectives is the number of replicates that do not fall between permissible limits. WQI, the score was scaled between 0 to 100; higher values represent better quality of water, e.g., excellent >80, good 60–80, fair 60–40, and poor <40.
