Of late there is lot of awareness among rural population
regarding the usage of toilets and related hygienic conditions. Government
agencies and NGO’s are participating in a big way in this programme. Government
of India initiated a program “Total Sanitation Campaign” (TSC) with the
objective of eradicating the practice of Open Defecation by 2012. This programme
has become part of Rural water supply schemes for the past 5-10 years. Water
supply schemes providing safe drinking water to villages and towns had priority
in earlier schemes. But now, water and sanitation schemes are being
contemplated simultaneously.
The objective of these schemes is to maintain adequate
sanitation and provide safe drinking water to rural population. There appears
to be a lot of progress achieved in sanitation and water programmes. In spite
of commendable progress achieved in these schemes, surveys have revealed that even
after a massive programme of toilets construction, there appears to be little
change in the overall health status of public. As per the surveys conducted in
Maharashtra, from 1996-97 to 1999-2000, more than 16 lacLatrines were
constructed, but still there is very little improvement in the health sector,
where the number of water borne diseases do not show any significant reduction
in the subsequent years.
Table 1: Status of water borne diseases in Maharashtra
|
Disease
|
1999-2000
(Attacks)
|
2000-2001
(Attacks0
|
2001-2002
(Attacks)
|
|
Gastroenteritis
|
65,067
|
32,479
|
67,295
|
|
Diarrhoea
|
10,23,194
|
11,46,395
|
11,04,841
|
|
Inf. Hepatitis
|
16,159
|
13,343
|
12,066
|
|
Typhoid
|
13,079
|
15,438
|
13,320
|
|
Cholera
|
348
|
1,043
|
1,326
|
Source: Drinking water and sanitation
in Rural Maharashtra: A review of policy Initiatives By Shree Keshab Das
Despite spending crores of rupees to contain water
pollution, water samples are continuously failing to meet the prescribed
quality standards. Same situation and conditions exist in other states.
Probable Reasons for Poor Groundwater Quality
·
The most common water quality problem in rural
water supply is bacterial contamination from septic tanks which are often used
in rural areas.
·
Pollutants also move into groundwater through
·
macro pores
·
root system
·
animal burrows
·
Abandoned wells.
·
Closer the contaminant source is to the water
well, more the chances of pollution.
·
Greater the distance between source of
contamination and groundwater abstraction structure, the more likely that
natural processes like Oxidation, Biological degradation and Absorption reduce
the impacts of contamination.
·
Septic tanks that do not have sewage treatment
systems.
·
Arrangements for safe disposal of solid waste, rain
water, and domestic liquid are lacking in many villages.
·
Effluent (overflow and leakage) from septic tank
can percolate (seep) down to the groundwater.
The risk of contamination is greater in the areas where shallow groundwater conditions exist. The Central Groundwater Board maintains National Network Observation Well data Water Level Information gis2.nic.in/cgwb/Gemsdata.aspx). As per this data, it is observed that in Andhra Pradesh state, as against 693 number of observation wells (generally one observation well represents one mandal having average of around 20 villages in Andhra Pradesh; in other states, Taluks and Blocks are common where more than one observation is established to monitor the seasonal water levels), 113 number of wells recorded 0-2 meter water level below ground level during rainy season. District wise details of shallow groundwater conditions (0-2m bgl) are given below.
Table 2: Shallow Groundwater Conditions
|
SL.NO
|
Name
of District
|
No
of observation wells taken for analysis
|
No
of wells in the range of 0-2 m water level during rainy season
|
Probable
reasons for near Ground level water
table conditions during rainy season.
|
|
1.
|
Srikakulam
|
50
|
9
no obs wells
|
Groundwater exploitation is
low,hilly area more
|
|
2.
|
Vizianagaram
|
24
|
10
nos
|
---Do----
|
|
3.
|
Visakhapatnam
|
46
|
3
|
Half of the area is tribal, other
half well developed in irrigation.
|
|
4.
|
East Godavari
|
74
|
22
|
Delta area, along the River
Godavari and Canal command area.
|
|
5.
|
West Godavari
|
62
|
15
|
Along the River Godavari with
canal net work .
|
|
6.
|
Krishna
|
67
|
13
|
More delta area.
|
|
7
|
Guntur
|
95
|
13
|
Along River Krishna and canal
net work.
|
|
8.
|
Prakasam
|
34
|
3
|
Sea coast and valley fill areas
|
|
9.
|
Nellore
|
68
|
5
|
Sea coast and valley fill areas
|
|
10.
|
Chittoor
|
96
|
1
|
Valley fill area
|
|
11.
|
Kadapa
|
77
|
1
|
Foot hill zone and valley fill area
|
|
12.
|
Anantpur
|
26
|
2
|
Valley fill area.
|
|
13.
|
Kurnool
|
41
|
5
|
Eastern portion dotted with hills.valley
fill
area and foot hill zone.
|
|
14
|
Hyderabad
|
34
|
5
|
Near surface water bodies.
|
|
15.
|
Rangareddy
|
95
|
7
|
------------do----------------
|
|
16.
|
Medak
|
24
|
4
|
Near surface water bodies and
foot hill zone
|
|
17.
|
Mahabubnagar
|
32
|
8
|
----------------do-------------------------
|
|
18.
|
Nalgonda
|
70
|
5
|
----------------do-------------------------
|
|
19.
|
Nizamabad
|
28
|
5
|
----------------do------------------------
|
|
20.
|
Warangal
|
94
|
11
|
Eastern portion hilly.valley fill and foot
hill
Zones.
|
|
21.
|
Karimnagar
|
44
|
7
|
Soft rock area and hilly
terrain in Manthani and Mahadevpur areas.Canal command and
Foot hill zones.
|
|
22.
|
Khammam
|
50
|
8
|
Major sedimentary rock terrain. River Godavari is flowing. Tribal
area is more.valley fill , foot hill zones and along major streams.
|
|
23.
|
Adilabad
|
81
|
14
|
Tribal and hilly area more.Along
the river,foot hill zone and valley fill areas.
|
Data based on 2008 and
2009 calendar years.
In the above data, observation wells where the depth to water level during rainy
season is 0-2m, are susceptible to groundwater contamination from septic tanks.
During rainy season, there is a possibility of mixing of groundwater, drainage
water and effluents from septic latrines. In such conditions, water borne
diseases affect the villagers who depend on groundwater for drinking water
purpose. Water-borne diseases affect the occasional guests, who visit their
native villages after spending long time in cities where safe drinking water is
available, and floating population. Contaminated water affects the children, old
people and occasional guests more when compared to the others. Probably local
residents develop immunity to accept contaminated water.
Similarly, in other states also (source: Groundwater
Scenario of India 2009-2010 CGWB year book), 4% to 75% of observation wells
recorded 0-2m depth to water level during rainy season. The highest percentage in Assam and lowest percentage
in Delhi. Karnataka state recorded 20% of observation wells, TamilNadu 5%
observation wells, Maharashtra 31% of observation wells recorded the depth to
water level from zero to 2m below ground level during rainy season. The near
ground level water table record
particularly during rainy season in Delta
areas, along the major Rivers, Canal and Tank command areas, Buried pediments, Valley
fill areas, Tribal and Forest areas where groundwater exploitation is low to
negligible. In absence of underground drainage system, groundwater
contamination is possible due to numerous types of human activities such as
1. Residential
2. Municipal
3. Commercial
4. Industrial and
5. Agricultural activities.
Water Related Diseases Due to Microbial Contamination
Water-borne diseases
are Viral, Bacterial, Protozoal and Thread worm.
Viral diseases are
infective hepatitis and polio-myclitis
Bacterial diseases
are diarrhoea, dysentery, cholera and typhoid
Protozoa diseases are
amoebiasis, giardiasis, helminthic i.e round worm and thread worm.
Mathemoglobinemia or blue baby syndrome, an illness
affecting infants, can be caused by drinking water that is high in Nitrate.
Microbial drinking water quality test is very important at
the Source and Point of abstraction. Household containers also spoil the water
quality. Monitoring of drinking water catchment, point of abstraction and
container water quality also should be carried out to find out where the
contamination of groundwater took place and level of pollution at different
places i.e at source, point of abstraction and in water containers.
Bacterial indicators E-coli, Thermotolerant coli presence in
drinking water indicates contamination. E-coli is derived mostly from human and
animal faeces. Thermotolerant coli grows at 44 degree centigrade. Faecal
Streptococci is an indicator of faecal pollution, and survive longer water
environment than E-coli.
Remedial measures
1. If
the groundwater contamination is very high, water supply must be abandoned as a
source of drinking water.
2. In other cases, groundwater can be treated and
supplied to public.
3. Prevent
the contaminated water to migrate.
4. Pumping the water, treating it and returning
it to the aquifer.
5. Allowing the contaminant to reduce naturally
following the implementation of appropriate source control.
6. In
the villages where safe drinking water is provided under Rural water supply
schemes, it is essential that water pipes should not go through sewage or
should not be submerged in sewage locations. Since in the villages, sewage
channels are open, there is the possibility of sewage mixing with pipe water.
7. Though
it is a monumental task, we wish someday underground drainage system should
come to all the rural areas which reduces the contamination of groundwater from
organic particles.
8. In
rural areas, at present, Rural water supply schemes are being implemented under
Water and Sanitation. The objective of the scheme is to provide safe drinking
water providing Tap connections and ensure all the households construct
latrines so as to avoid open defacation. But large number of villages still
depend on Dugwell or Borewell with handpump for drinking water. Also, open
defacation is practiced in many villages and few villages adopt septic latrines.
There is big drive in the rural areas to have latrines in each house. This
practice also leads to groundwater contamination.
9.
Efforts should be made to reduce the water
contamination by adopting better methods of sanitation. Disposal of drainage
water, sewage disposal, distance criteria maintained between sanitation and
drinking water source and abstraction. Periodic monitoring of microbial
groundwater quality and sanitation risk inspection data for water source (Dugwells
and Borewells) questionnaire as prescribed by WHO in their water quality
reports
