nataka state between 12
48
24.52
to 125359.85 North latitude and 772459.95 to 77306.72 East Lon-gitude. The major hydro-chemical facies that predominates in the study area is Ca2+–Mg2+–HCO@
@3 type during both pre- and post-monsoon seasons of the year 2007, could be as a result of dissolution of carbonate
minerals like calcite and dolomite prevailing in the study area. However, cation-exchange processes could be
responsible for the formation of the Ca2+-Mg2+-Cl–-S
water type (~32%) from the CaSO4, MgCO3 and NaCl type that are formed due to the dissolution of anhydrite, gypsum, magnesite and halite. Besides, suitability
of water for irrigation is evaluated based on sodium adsorption ratio, residual sodium carbonate, sodium per-
cent, salinity hazard and USSL diagram. Hydrogeochemical speciation model calculations carried out using
WATEQ4F program showed similar seasonal variation in the concentration of saturation indices of specific
mineral phases, majority of the samples kinetically saturated with carbonate minerals (viz., aragonite, calcite
and dolomite) indicating the influence of carbonate mineral phases on the chemistry of groundwater. On one
hand, the samples were significantly oversaturated with Florapatite while on the other, they were undersaturated
with respect to with anhydrite, gypsum and fluorite with halite being highly undersaturated. The Gibbs plots
also gave an indication that there exists an interaction between rock and the percolating water into the subsur-
face by means of mineral dissolution. Factor analysis determined two factors mainly responsible for water qual-
ity during pre- and post-monsoon seasons, accounting to 52.84% and 51.09% of total variance respectively. Q-
mode HCA Cluster analysis grouped the sampling stations into three clusters based on the similarity of water
quality while R-mode HCA grouped analyzed parameters into two groups based on the effects of factors in the
hydrochemistry.