5.1 INTRODUCTIONGroundwater is one of the nation's most important natural resources. As groundwater moves underground, it tends to develop a chemical equilibrium through chemical reactions. With the rise in groundwater level, the salinity of groundwater also increases due to the dissolution of mineral or mineral salts (Ballukraya and Ravi 1995; Subba Rao 2008). Groundwater hydrogeochemical processes studied in coastal aquifers (Jagannadha Sarma and Narayana Swamy 1981; Somasundaram et al. 1993; Manjusree et al. 2009), hard rock areas (Sreedevi 2002; Srinivasamoorthy et al. 2008; Gupta et al. 2009), fluoride regions (Ravindra and Garg 2006; Mor et al. 2009; Vikas et al. 2009) to determine whether groundwater quality is suitable for drinking and irrigation. Various geostatistical concepts are also used for the interpretation of complex data sets that can provide a better understanding of water quality parameters (Suk and Lee 1999; Suvedha et al. 2009; Yidana and Yidana 2010). In recent years, due to the advent of industrial growth, the large-scale application of synthetic fertilizers for agricultural production and the use of pesticides and insecticides for production have raised serious concerns about the susceptibility to groundwater contamination.5.2 GROUNDWATER SAMPLING AND CHEMICAL ANALYSISThe technical literature on groundwater sampling provides extensive information on some aspects of an effective sampling program. A high-quality hydrological and chemical data set is accurate, precise, comparable and complete. Groundwater contains a variety of chemical constituents at different concentrations. Most of the soluble constituents of groundwater come from soluble minerals in soils and sediments ...... middle of article ...... function of TDS (Gibbs, 1970). The Gibbs plot (Figure 5a-b) of the chemical data was primarily concerned with chemical weathering of the rock-forming mineral zone and therefore indicated that the chemical composition of these waters was primarily controlled by weathering reactions and could be altered at from the underlying biotite gneisses. biotite schists and granite as well as by the dissolution of their carbonate and silicate minerals and by the interaction between aquifer rocks and groundwater. PIPER'S TRI-LINEAR DIAGRAMWaters have been classified into hydrochemical facies indicating water types based on the subdivisions of the Piper-trilinear diagram suggested by Back (1961) and Hanshaw (1965). LegendA- Calcium typeB- Non-dominant typeC- Magnesium typeD- Sodium and potassium typeE- Bicarbonate typeF- Sulfate typeG- Chloride typepremonson