CS(AR)-3/2014 : Ground water quality mapping and surveillance for safe water supply in district Hardwar, Uttarakhand Bahadrabad Block

Abstract

The ground water quality of Bahadrabad Block in District Hardwar has been assessed to see the suitability of ground water for domestic and irrigation applications. Fifty two ground water samples from various abstraction sources were collected and analysed for various water quality constituents. The hydro-chemical and bacteriological data was analyzed with reference to BIS and WHO standards, ionic relationships were studied, hydrochemical facies were determined and water types identified. The concentration of total dissolved solids exceeds the acceptable limit of 500 mg/L in 42.3% of the samples analyzed but the values are well within the permissible limit of 2000 mg/L. The alkalinity values exceed the acceptable limit of 200 mg/L in 76.9% of the samples but these are also within the permissible limit of 600 mg/L. From the hardness point of view, more than 80% of the samples exceed the acceptable limit of 200 mg/L but these are also within permissible limits. Two samples of the study area exceed the acceptable limit of 45 mg/L for nitrate. Higher concentration of nitrate at these locations may be attributed due to improper sanitation and unhygienic conditions around the structures. Other constituents like chloride, sulphate and fluoride are within the acceptable limits.

The bacteriological analysis of the ground water samples indicates bacterial contamination at few locations. Inadequate maintenance of hand pumps, improper sanitation and unhygienic conditions around the structure may be responsible for bacterial contamination in ground water of the region and is a cause of concern. It is recommended that the water drawn from such sources should be properly disinfected before being used for drinking and other domestic purposes.

The presence of heavy metals in ground water has been recorded at many locations. The water quality standards have been violated for iron, manganese and nickel at many locations. The concentration of iron varies from 3002 to 19771 p,g/L as against the acceptable limit of 300 µg/L. The concentration of manganese varies from 5.5 to 2712 p.g/L as against the permissible limit of 300 ug/L and concentration of nickel varies from 63 to 527 pg/L as against the permissible limit of 20 pg/L. The concentration of copper, chromium, lead, cadmium and zinc were found well within the permissible limits at most of the locations. An attempt has also been made to classify the ground water on the basis of different classification schemes, viz., Piper trilinear, Chadha's diagram and U.S. Salinity Laboratory classifications. The grouping of samples according to their hydrochemical facies indicates that all the samples of the study area fall under Ca-Mg-HCO3 hydrochemical facies. The suitability of ground water for irrigation purpose has been evaluated based on salinity, Sodium Adsorption Ration (SAR), Residual Sodium Carbonate (RSC) and boron content. In general the ground water of Bahadrabad Block is safe for irrigation purpose. According to U.S. Salinity Laboratory classification of irrigation water, about 50% of the samples fall under water type C2-S1 and about 50% under water type C3-S 1 type.