Physico-chemical characteristics of groundwater in
parts of Eastern Karnataka are examined to determine whether they conform to the quality standards
of water used for drinking, agriculture and industrial end uses. Eighty eight samples from forty five
villages have been analysed for this purpose. Cation
abundances in the groundwater are in the order:
Na+ > Ca++ > Mg++ > K
+. Anion abundances
are in the order HCO−
3 > Cl− > SO2
4 > NO−
3 > F
−.
Only in one locality, SO2
4
content is very high. According to Piper’s classification, 42% of the water samples
belong to Ca–Mg–Cl type; 30% to the Ca–Mg–HCO3,
16% to Ca–Na–HCO3, 9% to NaCl and 3% to NaHCO3
types. Gibbs plot shows that water–rock interaction is
the dominant process controlling the major ion chemistry, although there is evidence of evaporation at some
places. Out of 45 villages, excess of fluoride, nitrate
and uranium are found in 23, 28 and 26 villages respectively. Phosphate is higher than 1 mg/l in all the
villages. Lithium exceeds the permissible limit in 27
out of 43 localities. Concentrations of other trace
elements Ag, Al, Ba, Tl, As, B, Co, Cr, Cu, Fe, Li,
Mn, Ni, Pb, Se, V, Zn and U were determined in selected samples. Arsenic exceeds the permissible limit
for drinking water in one village. Groundwater in
21 out of 45 villages is suitable for agriculture, while