An assessment of the quality of ground water for the Kadiri schist
belt of Anantapur district has been carried out with an objective to determine
the hydrochemical variability. A total of 41 representative samples from
different geological formations were collected in both pre- and post-monsoon
seasons and analyzed for the major chemical constituents, viz. Ca, Mg, Na, K,
CO
$_3$
, HCO
$_3$
, SO
$_4$
, Cl, F, pH and EC. Cluster analysis, a multivariate statistical
tool, has been used in the study as qualitative means for differentiating
ground waters into distinctive types. Based on hydrochemistry, chemical
variability deciphered from cluster analysis suggests three distinct types of
ground waters, viz. mixed type (Si-Ec-Ca-Cl-SO
$_4$
-Mg or Ca-Cl-EC-Si-Mg) and
Na-HCO
$_3$
type in both pre- and post-monsoon, whereas in post-monsoon in addition
to these two types one more type has been formed in the form of SO
$_4$
. Sulphate
type occurs only in the post-monsoon season due to the use of excessive sulfate
fertilizers to improve the yield of the crops. Ground water of the study area
is (except fluorine) within the permissible limits for domestic and irrigation purposes.
