Ground water quality and its suitability for drinking after Tsunami in coastal belt of Kanyakumari to Colachel, Tamil Nadu, India

• Published in: Nature environment and pollution technology Vol. 7; no. 2; pp. 181 - 188
• Main Authors: Perumal, S B, Thamarai, P
• Format: Journal Article
• Language: English
• Published: 01.06.2008
• Subjects: Brackish; Freshwater; Marine; ISW, India, Kerala, Kanyakumari; India, Kerala, Colachel; ISW, India; ISW, India, Tamil Nadu
• ISSN: 0972-6268

Hydrochemistry of groundwater in coastal area of Kanyakumari to Colachel after Tsunami was used to assess the quality of groundwater for determining its suitability for drinking purposes. Physical and chemical parameters of groundwater such as electrical conductivity, pH, total dissolved solids (TDS), Na super(+), K super(+), Ca super(2+), Mg super(2+), Cl super(-), HCO super(-) sub(3), CO super(2) sub(3) super(-), SO super(2) sub(4) super(-), NO super(-) sub(3), F super(-), B super(-) and SiO sub(2) were determined. Concentrations of the chemical constituents in groundwater vary spatially and temporally. Interpretation of analytical data shows that mixed Ca-Mg-Cl, Ca-Cl and Na-Cl are the dominant hydrochemical facies in the study area. Alkali earths (Ca super(2+), Mg super(2+)) and strong acids (Cl super(-), SO super(2) sub(4) super(-)) are slightly dominating over alkalis (Na super(+), K super(+)) and weak acids (HCO sub(3), CO super(2) sub(3) super(-)). The abundance of the major ions is as follows: Na super(+)> Ca super(2+)> Mg super(2+)> K super(+)=Cl super(-) > HCO super(-) sub(3) > SO super(2) sub(4) super(-) > NO super(-) sub(3) > CO super(2) sub(3) super(-). Groundwater in the area is generally very good, pleasant, fresh to brackish, average to very low saline and low alkaline in nature and fit for drinking purposes. Permissible average total hardness and TDS in all places of the study area identify the suitability of groundwater for drinking. Based on the TDS value, the groundwater in these areas is of bicarbonate/calcium chloride/sodium chloride type. Fluoride and boron are within the permissible limits for human consumption and crops as per the international standards. Nitrate concentration is slightly high in some areas. In the study area less groundwater extraction keeps the water table high. The elevated topography, more rainfall and limited groundwater extraction, keeps the Kanyakumari coastal belt free from seawater intrusion. The surface water resources have been fully utilized. The surface flow is more during monsoon periods. Quality of water is generally good throughout the district except some places in the study areas like Keelamanagudi, Thengampudur and Colachel and some pockets along the coastal belt. Comparing the results of water parameters before and after Tsunami there is not much change in the quality of water for drinking.