Comparative Studies on Ground Water Quality of Krishnagiri, Tiruvannamalai, and Vellore Districts of Tamil Nadu, India

In the current study, groundwater levels were monitored in three districts (Krishnagiri, Vellore, and Tiruvannamalai) in the northwest of Tamil Nadu, India. Water samples were taken at 28 locations, including 8 in Krishnagiri, 13 in Vellore, and 7 in Tiruvannamalai. All twelve borewell samples, twelve open well samples, three lake samples, and one municipal source sample were analyzed. The physical and chemical characteristics were examined and recorded. The three districts of water samples were analyzed for appearance, odor, turbidity, total dissolved solids (TDS), electrical conductivity (EC), pH, total hardness (TH), total alkalinity (TA), calcium (Ca), magnesium (Mg), iron (Fe), sodium (Na), potassium (K), free ammonia (NH3−N), nitrate (NO3−), chloride (Cl−), heavy metals, sulfides (S2−), oil and greases fluoride, sulfate (SO42−), and phosphate (PO43−). Higher values of turbidity, TDS, EC, pH, TA, TH, Ca, Mg, Fe, Na, K, NH3−N, NO3−, Cl−, F−, SO42− and PO43− are found in Krishnagiri district, respectively. For TDS, TH, Ca, Mg, NH3−N, NO3−, Cl, and F− exceed the WHO and TWAD permissible limits in Krishnagiri district, In the pH ranges of Vellore district, TSS, TDS, Ca, SO42−, BOD, COD, S2−, NH3N, Na, TA, TH, hardness of Ca of hardness and Mg hardness were recorded, respectively. Phenolic compounds, hexavalent chromium, total chromium (Cr), F−, and oil and greases showed minimum detectable amounts in the Vellore district water samples. Higher and lower values of EC, pH, TSS, TDS, Cl, SO42−, BOD, COD, TA, TH, Ca and Mg hardness is recorded in Tiruvannamalai district water samples, respectively, and other parameters are below the minimum detectable limits. Compared to WHO and TWAD standards, the maximum values of the water sample exceed the permissible limits in the present study of three districts. Consequently, public awareness campaigns regarding the indicators of water quality and their significance will be scheduled in addition to education in schools, colleges and the public.