under unconfined condition within 17m
Kolkata:
Kolkata also faced the same problem
like
Chennai
but
with
different
consequences. The nature of the aquifer
is semi confined to confined. Kolkata is
underlain by 762m thick unconsolidated
alluvium, which overlies a huge pile of
unconsolidated
to
semi-consolidated
sediments deposited on the basement.
The structure and lithology of the
sediments indicates number of pulses of
sedimentation, marine transgression and
regression and tectonic uplift from
Cretaceous to Pleistocene times.
A typical hydrochemical situation exists
in KMC area. In the major part of KMC
area fresh ground water overlies the
brackish ground water except in the
western part starting from Fort William
in the central part on the bank of river
Hugli and Kalighat in the south and in a
localized body around Kasipur, west of
Dumdum in the north, where brackish
ground water overlies the fresh ground
water. In the levee deposit on the bank
of Hugli river thin lens of shallow
aquifer occur within 12m bgl, where
ground water occurs under water table
condition. Ground water also occurs
below
ground
level
in
the
marshy/swampy lands around Ballyganj,
Tollyganj, Tiljola, Dhakuria, Kasba,
Santoshpur, Garia, Behala, Barish and
Thakurpur.
The Gross Annual Ground water draft
for domestic & industrial use in Kolkata
is 305.20 Million litres per day. With
such withdrawal Groundwater level has
been lowered to a large extent over the
years. Saline groundwater in shallow
aquifer within 120 m. bgl in the western
part of the city, and the deeper aquifer
below 120 m. b.g.l.
in eastern part.
KMC has reported sporadic occurrence
of Arsenic beyond permissible limit
(0.05mg/l) in groundwater in a few
places. Groundwater tapped by open
wells in the marshy/swampy lands is
hydraulically connected to the surface
water bodies, and is biogenetically
polluted.
Ministry level coordination to clean
up Ganga
The union Water Resource Ministries
GOI has signed a joint MOU with seven
Ministries to
carry forward multi-
sectoral activities for a minimum of
7
Integrated River Basin Management Society