Status of Ground water Quality, Hoskote Taluk, Bangalore Rural District, Karnataka, India.

Abstract

The quality of groundwater in nature is determined by quantum and nature of recharge, chemical composition of the soil cover and its thickness, mineralogical make up of the aquifer, residence time of the water which is governed by the transmissivity of the formation. The two important characteristics of the crystalline terrain, which covers practically the entire Taluk, are the heterogeneity and preferred flow paths. They have a dominant role to play in determining the quality of the ground water with the result; large variations are noticed in short distances. Thus it is not uncommon to get varied quality of water even in a small village. This fact is to be borne in mind while locating sources of water supply for various uses. Quality data in respect of 14 parameters of all the drinking water sources in the villages is available with PRED. Summaries of bore well sources, Gramapanchayat wise which is presented in Table 1.1. The same has been collected and analysed. The range of value in respect of 14 parameters are given in table 1.2 Table 1.3 summarizes the number of wells with a quality problem in the Taluk. As seen the most commonly observed problems relate to the total dissolved solids, Total hardness, Turbidity, Calcium, Iron and Fluoride. The strategy to be adopted in providing solutions to these villages is discussed. As for the irrigation requirement, the two important quality parameters are Sodium adsorption ratio and total dissolved solids are indicated by the Specific conductance of the water These determine the Salinity and Sodium hazard from the irrigation water. These determined from the results available in the records of DMG. Considering the fact that large areas of the Taluk are covered by red soils and mixed soil, it is very important to study the soil water inter relationship before undertaking irrigation practice. It can be safely concluded that in red soil areas, the quality of ground water is safe for irrigation and has low to medium salinity-low sodium hazard.