Geoscience Reference
In-Depth Information
GEOCHEMISTRY OF GROUNDWATER AND THEIR
RELATIONSHIP WITH GEOLOGICAL FORMATIONS
V. K. SAXENA
∗
,N.C.MONDALandV.S.SINGH
National Geophysical Research Institute
Hyderabad 500 007, India
∗
vks 9020010@yahoo.co.in
Studied area is a tribal area of Warangal District, Andhra Pradesh (A.P.),
India. This is about 1,500 km
2
and has different types of rock formations such
as granite gneisses, sandstones, pakhals, and alluvium, etc. This area was facing
groundwater problems since two decades. A large number of shallow bore wells
were drilled. These bore wells are discharging water from 10,000 to 25,000 l/h.
A large number of groundwater samples were collected and quantitatively
analyzed. The results indicate that: (1) These groundwaters are classified as
Na-Ca-Cl-HCO
3
and mixed water types. (2) Fluoride is more in groundwa-
ter of granite gneisses areas. (3) Concentrations of aqueous ionic species have
changed with different rock formations. (4) Groundwaters of granite gneisses
areas are more in Total Dissolved Solids (TDS). (5) TDS of groundwater and
depths of bore wells have shown a good correlation.
1. Introduction
Groundwater is valuable only when its quality is suitable for the purpose
for which it is being explored. Suitability of groundwater for particular pur-
pose depends upon the standards of acceptable quality for that use. The
acceptability of groundwater for a particular usage is essentially dictated
by the standards of acceptable/permissible limits.
1
-
4
Warangal, which is
located in the southeast parts of India, has been facing groundwater prob-
lems in term of quantity and quality. This is part of forest and developed
for the habitation of tribals. Their main source of living is based on agricul-
ture. Because of the lack of groundwater or surface water, these people are
facing various types of problems for their survival. State Government had
drilled a large number of bore wells (
>
40 bore wells, 10-70.5 m depths). It
is interesting to note that this region is having different types of rock for-
mations, which is Recent to Archaean.
5
For the study of chemical quality of
these groundwaters in this area, the water samples were collected from the
locations of these bore wells, which are shown in Fig. 1. This paper evalu-
ates (1) quality of groundwater in relation to potable purpose, (2) changes
271
