Hydrochemical analysis and evaluation of groundwater quality in Tumkur Taluk, Karnataka state, India.

Tumkur Taluk is located in the southeastern corner of Karnataka state between 13 degrees 06'30'' to 13 degrees 31' 00'' North latitude and 76 degrees 59' 00'' to 77 degrees 19' 00'' East Longitude. The Taluk spreads over an area of 1043 sq.km falling within the semiarid region and frequently facing water scarcity as well as quality problems. The major sources of employment are agriculture, horticulture and animal husbandry, engaging almost 80% of the workforce. Water samples are collected from 269 stations during pre-monsoon and 279 locations during post-monsoon of the year 2006, and were subjected to analysis for chemical characteristics. The type of water that predominates in the study area is Ca-Mg-HCO3 type during both pre- and post-monsoon seasons of the year 2006, based on hydro-chemical facies. Besides, suitability of water for irrigation is evaluated based on sodium adsorption ratio, residual sodium carbonate, sodium percent, salinity hazard and USSL diagram.