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A R E P O R T
Under the component of drinking water supply,
Bharat Nirman envisages -
- Coverage of uncovered habitations of
CAP'99 by 2008-09;
- Tackling
of water quality problem in affected habitations
by 2008-09;
- Coverage
of all rural schools with drinking water supply
by 2006-07; and
- Consolidation
of coverage by providing drinking water facilities
in shipped back habitations by 2008-09.
Coverage of uncovered habitations
of CAP'99 by 2008-09
There
is no uncovered habitation in the State under
CAP'99
Tackling of water quality problem in
affected habitations by 2008-09;
The
State of West
Bengal has the following
quality problem in drinking water namely, (i) Arsenic (ii) Fluoride (iii) Salinity
(iv) Iron.
(i) Arsenic
In
West Bengal, Arsenic contamination of ground water
was first detected during early eighties in different
districts adjoining Bhagirathi
/ Hooghly River. Investigation showed
that the same is due to presence of Arsenic beyond
permissible limit of 0.05 mg/l. in ground water. The arsenic problem
was found to be GEOGENIC i.e. due to presence
of excess quantity of arsenic in geological formation. Ground water was the
main and staple source of drinking water in such
areas due to its case, inexpensive and location
specific abstraction. Therefore, the drinking
water supply system in the affected areas received
a serious setback owing to Arsenic contamination
of Ground Water.
As
per latest observation, ground water in 79 Blocks
(out of 341 blocks in the State) in the District
of Malda (7 out of 15 Blocks), Murshidabad (19 out of 26 Blocks), Nadia
(17 out of 17 Blocks), North 24 Parganas (19 out of 22 Blocks), South 24
Parganas (9 out of 29
Blocks), Howrah (2 out of 14 Blocks), Hooghly (1 out of 18 Blocks) and Bardhaman (5 out of 31 Blocks) is under
the risk of Arsenic contamination. 2001 Census population
of these blocks is 166.49 lakh
(out of State Rural Population of 577.35 lakh).
Various
short term and mid term measures have been adopted
in the past, as an immediate and intermediate
intervention. However, surface water
based water supply schemes where feasible have
been found to be the best and permanent solution.
After
so many years of experience towards Arsenic Mitigation
Measures it was felt essential to review the whole
situation in order to implement future mitigation
programmes in much more judicious and organized
manner.
Some of the facts about the efficacy of
the various short term and medium term measures
that has been observed over the years are given
below:
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- Ringwells
are not well accepted by the people
and prone to bacteriological contamination.
- The
Arsenic Treatment Unit attached to the
hand pump tubewells have been found to be very effective
as an intermediate intervention, however,
in the long run these units have failed
to serve the purpose due to O&M
and sludge disposal problem
- The
deep aquifer replacement tubewells, in some cases, turned
out to be ineffective due to leaching
of Arsenic to deeper layer from top
- Tubewells
of some of the ground water based piped
water supply schemes, though sunk in
deeper arsenic free aquifer, showed
the presence of arsenic in due course
of time due to leaching action.
- In
view of the above, a Master Plan is
under preparation on future mitigation
measures in consultation with the Arsenic
Task Force, Govt. of West
Bengal. The Master
Plan is being prepared in order to cover
all the arsenic affected habitations
so far identified on long term basis.
In preparing the Master Plan
the following recommendation of the
Arsenic Task Force has been considered.
- All
the arsenic affected villages to be
covered by piped water supply schemes.
- Areas
covered by existing Short Term and Mid
Term Measures such as ATU attached Hand Pump Tube
wells,
- Replacement
Tube wells etc. should also be included
within the future plan of action.
- Attempts
to be made to cover the affected areas
with surface water wherever available.
- Affected
areas, which cannot be covered under
the existing / proposed surface water
based piped water supply schemes, should
be served from ground water based piped
water supply schemes.
- All
proposed ground water based new piped
water supply schemes should be provided
with an Arsenic Removal Plant unless
a safe aquifer well separated from the
contaminated layer by thick impermeable
barrier is available.
- All
existing ground water based piped water
supply schemes in the affected areas
should be provided with Arsenic Removal
except where safe aquifer will separated
from the contaminated layer by thick
impermeable barrier is available.
- As
first step towards implementation of
the Master Plan, it was imperative to
have complete picture of the arsenic
affected habitations in the Arsenic
Affected Blocks.
As per the previous Water Quality
Survey 2000 and subsequently the Habitation
Survey 2003,
a figure of arsenic affected habitations
was arrived at, based on the water quality
test for 10 to 25% of the hand pump
fitted public tubewells in each habitation of
the affected blocks. Meanwhile,
a complete water quality survey of all
the public hand pump fitted tubewells in the arsenic affected
blocks totaling to 1,35,000 has been
taken up under the Joint Plan of Action
with UNICEF.
- Under
the present study all the public hand
pump tubewells in 73 Blocks out of 79
affected Blocks have been completed
and so far 6611 habitations have been
found to be affected with arsenic. Based
on arsenic affected habitations so far
identified and in consideration of the
recommendation of the Arsenic Task Force,
Govt. of West Bengal, Action
Plan has been drawn which is shown in
Table-I.
- It
bears on mention here that in preparing
the Surface Water Based Schemes, the
areas that can be conveniently covered
by perennial sources have been considered.
From the previous experience
it has been observed that the Arsenic
Contamination in ground water is dynamic
in nature which spreads both horizontally
and vertically depending on hydro-geological
condition of the area. Therefore, attempts
have been made to cover the whole of
the Block declared arsenic affected
to avoid replication of similar scheme
in future, which may prove uneconomic.
- In
case of ground water based scheme also,
some of the adjoining or encircled village
have been included in the scheme for
similar reason.
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| (ii)
Fluoride |
-
In
West Bengal
detection of fluoride contamination
is a recent phenomenon. Excess fluoride
in drinking water was first detected
in the year 1996 in Nalhati-I
Block of Birbhum
District. Since then the
detection of fluoride continued with
limited no. of Water Testing Laboratory,
having facility for fluoride testing.
Some fluoride affected habitations
were identified in the Water Quality
Survey 2000. This database
was prepared on the basis of test results
of at least one tubewell
in each habitation.
Subsequently, under the Habitation
Survey 2003, a more comprehensive identification
of fluoride affected habitations could
be made on the basis of test results,
of 10 25% of total tubewells in each habitation. According to
the Habitation Survey 2003, excess fluoride
was detected in 665 habitations in West Bengal spread of 45 blocks
in 9 districts.
- Considering
increasing occurrence of fluoride contamination
in ground water, the Govt. of West
Bengal constituted a Fluoride
Committee vide G.O. No. PHED/324/3D-27/2003
dated 30.12.2003.
The Fluoride Committee, which
comprises of experts from different
Govt. Organizations and Professional
Institutes, decided to conduct a Rapid
Assessment
of fluoride contamination in ground
water of West Bengal, to have a first
hand knowledge of the actual spread
of the problem. Accordingly,
a list of 105 blocks in 12districts
was prepared based on the previous test
results and the hydro-geological condition
of vulnerable areas. Water samples
were collected from the designated areas
on random basis keeping due regard to
the geographical condition.
- The
Rapid Assessment is now complete and
excess fluoride has been found in 43
blocks of 7 districts. A Joint Plan
of Action has been taken up with UNICEF
which encompasses complete testing of
water testing of all the public tubewells
in the affected blocks and draw up Action
Plan on Fluoride Mitigation as has been
done in case of Arsenic Mitigation.
- Presently,
under the Bharat
Nirman, an action plan for fluoride
affected habitation has been prepared
based on water quality data of Habitation
Survey 2003 and shown in Table-I. The above Action
Planneeds to be revised once the test of all the public tubewells are complete.
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| (iii)
Salinity |
- The
saline affected habitations were identified
as per Water Quality Survey 2000 and
subsequently in Habitation Survey 2003
based on the test results of 10 25%
of tubewells
in each habitation.
The no. of saline affected habitations
is 811 as per 2003 Habitation Survey.
Presently, the action plan under Bharat
Nirman has been prepared based on
such data and shown in Table-I
- Here
it would be pertinent to mention that
a complete test of all the public tubewells
in the saline affected blocks of West
Bengal jointly with UNICEF, is under
the contemplation of Chief Engineer,
Water Quality Management, PHE Dte. Once 100% public
tubewells
are tested the above action plan for
saline affected habitation may call
for a revision.
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| (ivi)
Iron |
- Like other water quality parameters, iron was
also tested under Water Quality Survey
2000 and subsequently, under Habitation
Survey 2003. The no. of Iron affected
habitations is 11883 as per 2003 Habitation
Survey. The action plan under Bharat
Nirman, for iron affected habitations
is underpreparation.
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Coverage of all rural schools with drinking
water supply by 2006-07
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An action plan for coverage
for rural schools with drinking
water supply has been prepared
and shown in Table-II. This
action plan has been prepared
in consultation with the
School Education Department
of this Govt. who is the
nodal department for this
work.
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Consolidation of coverage by providing drinking
water facilities in slipped back
habitations by 2008-09.
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An
Action Plan in this regard
has been prepared and shown
in Table-III.
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