## 2 Research Methodology
### Sampling Techniques and Equipment
\begin{table}
\begin{tabular}{l c c c c c c c c c c c c} \hline \hline Parameters & A1 & A2 & A3 & A4 & A5 & A6 & A7 & A8 & A9 & A10 & A11 & A12 \\ \hline Color & \textless{}1.0 & \textless{}1.0 & \textless{}1.0 & \textless{}1.0 & \textless{}1.0 & \textless{}1.0 & \textless{}1.0 & \textless{}1.0 & \textless{}1.0 & \textless{}1.0 & \textless{}1.0 & \textless{}1.0 & \textless{}1.0 \\ \hline Odor & Agree-able & Agree-able & Agree-able & Agree-able & Agree-able & Agree-able & Agree-able & Agree-able & Agree-able & Agree-able & Agree-able & Agree-able \\ \hline pH & 7.99 & 7.42 & 7.23 & 7.16 & 8.21 & 7.67 & 7.78 & 7.92 & 7.25 & 7.12 & 8.11 & 8.07 \\ \hline Turbidity & \textless{}1.0 & \textless{}1.0 & \textless{}1.0 & \textless{}1.0 & \textless{}1.0 & \textless{}1.0 & \textless{}1.0 & 7.0 & \textless{}1.0 & \textless{}1.0 & \textless{}1.0 \\ \hline Nitrate (as NO\({}_{3}\)) & 6.5 & 7.1 & 15.8 & 13.2 & 28.1 & 21.5 & 12.9 & 21.6 & 12.0 & \textless{}2.0 & 58.2 & 32.6 \\ \hline Total (as CaCO\({}_{3}\)) & 142.1 & 147.1 & 548.4 & 415.0 & 586.8 & 479.3 & 416.7 & 577.8 & 35.6 & 32.6 & 767.2 & 330.5 \\ \hline Iron (as Fe) & \textless{}0.1 & \textless{}0.1 & \textless{}0.1 & \textless{}0.1 & \textless{}0.1 & \textless{}0.1 & \textless{}0.1 & \textless{}0.1 & \textless{}0.1 & \textless{}0.1 & \textless{}0.1 \\ \hline Chloride (as Cl) & 98.7 & 118.3 & 487.6 & 385.8 & 541.5 & 412.7 & 328.9 & 488.5 & 17.2 & 7.5 & 792.4 & 216.8 \\ \hline Fluoride (as F) & 0.5 & 0.4 & 0.7 & 0.4 & 0.4 & 0.5 & 0.3 & 0.5 & \textless{}0.1 & \textless{}0.1 & 1.3 & 1.0 \\ \hline TDS & 319.5 & 312.4 & 1275.6 & 893.3 & 1295.3 & 934.4 & 945.2 & 1163.6 & 89.4 & 79.2 & 1923.2 & 475.8 \\ \hline Calcium (Ca) & 31.5 & 37.5 & 98.7 & 79.5 & 106.9 & 82.7 & 75.5 & 102.3 & 8.9 & 8.2 & 109.7 & 61.7 \\ \hline Magnesium (as Mg) & 15.2 & 12.8 & 72.4 & 51.9 & 76.7 & 65.4 & 54.7 & 77.3 & 3.2 & 2.9 & 118.3 & 39.9 \\ \hline Sulphate (as SO\({}_{4}\)) & 14.6 & 11.5 & 95.2 & 68.3 & 104.1 & 71.4 & 67.9 & 98.2 & 28.5 & 14.7 & 195.8 & 93.2 \\ \hline Alkalinity (as CaCO) & 85.7 & 88.5 & 187.8 & 139.2 & 156.3 & 198.6 & 168.3 & 162.1 & 63.4 & 41.3 & 198.4 & 105.4 \\ \hline Total (Caliform) & Absent & Absent & Absent & Absent & Absent & Absent & Absent & Absent & Absent & Absent \\ \hline _Escherichia_ & Absent & Absent & Absent & Absent & Absent & Absent & Absent & Absent & Absent & Absent \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Physicochemical and microbiological parameters of collected water samples during the monsoon season. In Table 4, the collection and testing period took place in the last week of June 2020, with the specific dates being as follows: Nangloi--June 13 to 18, Okhla Industrial Area--June 18 to 23, and Karol Bagh--June 17 to 22, signifying the pre-monsoon season. The mean values for all parameters during the pre-monsoon period are as follows: pH--7.713333, nitrate--23.06667, total hardness--413.7, chloride--338.3083, fluoride--0.625, TDS--964.0917, calcium--708, magnesium--56.880833, sulphate--777.16667, alkalinity--139.5333. In Table 5, the collection and testing period occurred in July 2020. The mean values for all parameters during the monsoon period are as follows: pH--7.6275, nitrate--19.29167, total hardness--372.425, chloride--324.6583, fluoride--0.554545, TDS--808.90883, calcium--66.925, magnesium--49.225, sulphate--71.95, alkalinity--132.9167. In Table 6, the collection and testing period took place in the 1 st week of October 2020. The mean values for all parameters during the post-monsoon period are as follows: pH--7.5767, nitrate--20.554, total hardness--350.525, chloride--297.491, fluoride--0.52, TDS--801.516, calcium--66, magnesium--44.525, sulphate--69.6, alkalinity--124.9. The most concerning parameters revealed by this study are total hardness and the presence of bacteria. Immediate attention should be given to these issues as they can pose health hazards and related problems. Therefore, to assess the fitness and suitability of water for human use, the water quality index has been evaluated using the methodology proposed by [28].