Geoscience Reference
In-Depth Information
at deeper fracture zones.
5
Average depths of weathered zone vary from 8
to 18 m. Groundwater table lies in between 5 and 15 m and mostly depend
upon rock formations. Main soils are silts, black cotton soils, clay loams and
sandy soils. Main crops are paddy, jawar, maize, cotton, chilies, tobacco,
and pulses, etc.
3. Water Sample Collection and Analytical Techniques
Water samples were collected in 1-liter polythene bottles and the standard
instrumental/chemical techniques were used for water samples analysis.
6
-
8
4. Results and Discussions
Chemical analyses of these water samples are shown that the groundwa-
ters are nearly neutral to mildly alkaline in pH (7.2-8.2). Electrical con-
ductivity varies from 328 to 1,610
µ
S/cm, and shows a big variation. In
25% samples total dissolved solids (TDS) are not within the permissible
limit of potable/domestic water.
2
The water emerges from bore well Nos.
9, 10, 11, 12, 15, 21, 26, and 28 have shown enrichment of Na, Ca, Cl,
HCO
3
, and F in water which is more than the permissible limit of drink-
ing water.
2
Maximum electrical conductivity (1,610
µ
S/cm) was found in
Govindraopet (bore well No. 10), which is located in rock area and mini-
mum in Khanepur (328
µ
S/cm) in the bore well No. 32, where geological
formation is recent. Similarly, high Na and Ca were found in bore wells
Nos. 21 and 9 both are in granites and lowest in bore wells Nos. 40 and
32 are in recent. Maximum Mg (45 mg/l) was determined in Gudur (bore
well No. 26 in Upper Gondwanas) and minimum in Khanepur, alluvium
(5 mg/l). Thus, it is found, groundwaters with low TDS are associated with
alluvium. Govindraopet groundwater is also enriched in HCO
3
and chlo-
ride, which shows the higher dissociation rate in hard rocks. The variability
of aqueous ionic species of groundwater with different types of rock for-
mation, may indicate, the possibility of changing the hydrochemistry with
geological formations. Based on chemical analysis data, these groundwaters
have been classified as: Na-Ca-Cl-HCO
3
and mixed types. Chemistry of
these bore wells and their locations, indicated that groundwater emerges
in sandstone and alluvium are mostly have low salinity, whereas shales and
clay have medium to high; and granite gneisses with high salinity. However,
the concentrations of cations (Ca, Mg, Na, and K) and anions (Cl, HCO
3
and SO
4
), which gives preliminary information about the water quality and
