Water Resources Management.200151616
Transcript of Water Resources Management.200151616
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N Roy
Table 3: Drinking Water Demand
Note: As the living standards of the country s population rises so does their aspirations and
demands, thus the per capita water supply demand has been raised with time.
Table 4: Total Water Demand and water available from SW and GW sources
From table 4, it can be seen that the projected
water demand iIl- the year 2050, is higher than the
total water availability. However looking to the
drastic effects of global warming and climatic
change, and also to the improving standards ofliving
ofIndia s citizens, the situation of water availability
falling short of the water demand can come much
for drinking, cooking, bathing and washing.
For a start this practice .should be
implemented in our 6 metros. This will
naturally reduce the demand of water thereby
bringing down the extraction of water from
.the source, which will increase the source s
longevity. .
81.
Year
Population
Per Capita daily
Total Water
No.
in billions
Water Demand
Demand in
in litres
BCMIYear
1 2
3
4 5
.
1
2
1.027
100 37.5
2 2011
1.218 115
51.12
3
2025
1.333
125
60.81
4
2050
1.581
150
86 56
81.
Year
Water Demand
Available from Available from Total Water
No.
in BCM
8W in BCM GW in BCM
available in BCM
1 2 3
4 5 6
1
2001 37.5 20.16 58.60 78.76
2
2011 51.12
18.03
62.12 80.15
3 2025
60.81
14.85
56.02 70.87
4
2050
86 56
12.63 56.49
69.12
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Roy
(d)
of distribution lines is to the tune of 30-35
in most Indian cities. This loss is substantial
and in current language called Non-Revenue
Water (NRW).
Actually this quantity of water is being treated,
disinfected, pumped and being conveyed, but
due to leakage do not reach the public and
thus ~ot accounted for. Exercise on a war
footing should be taken up immediately to
bring down this NR\V>to a reasonable limit
say 12-15 . Singapore has reduced it to 6 ,
whereas it is around 13 and 18 in Europe
and China.4 This leakage control will add a
substantial quantum to the daily water being
supplied in the town/city, and all of this will
be accounted for and revenue will be earned.
Another task which requires immediate
attention is compulsory metering, even in our
metros the entire distribution network and
water connections are not metered and the
customers are being billed at a flat rate, which
is on a much lower scale than what actually
is being consumed. Metering will not only
increase the revenue of the Water Supply
Authorities, but also make the public more
conscious regarding wastage of water.
In rural areas and semi-urban areas where
people are not residing on the banks of
streams/nallahs/smaJl rivers, blocking the
flowing water going to waste should be taken
by construction of dykes, check bunds,
percolation tanks/trenches, desiltationof
existing tanks/ponds, building of percolation
trenches at the foot of the slope of hills, spring
(e)
recharging of existing tube wells etc. This will
help in recharging the existing aquifers.
Waste Water Treatment, Reclamation and
its Reuse in China
I visited China recently in September 2011 to
attend an International Water Convention hosted
jointly by International Water Association (IWA)
and Xian University of Architecture and Technology
at Xian. The theme was Cities of the Future-
Technologies for Integrated Urban Water
Management .
In China there are many water stressed cities
like Beijing, Tianjin, Jinan, Xian etc. these 4 and a
few others have taken up the task oftreating their
domestic waste water, reclaiming it and then
reusing it for public park watering, landscaping,
water bodiesllakes replenishment, toilet flushing,
and road washing. Domestic potable water supply
treated, disinfected to the set standards are supplied
for drinking, bathing, cooking and washing only.
Dual pipe system is used; one pipe supplies drinking
and water for other domestic purposes while the
second pipe conveys water for toilet flushing,
gardening etc. Xian city has presently a per capita
availability of water of only 234 cubic metres.
After the conclusion of the Convention,
theParticipants were taken for a Technical Visit to'
the Siyuan UniversitY.lil.nd Xian University for
Architecture and Technology Campus, where this
experiment has been implemented and is being-
successfully being operated and maintained.
The University Campus is spread over 8.0
hectares and has 60 green cover, there are 25,000
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Fig 1 shows - the present water supply
scenario in the University Campus, and how by
treatment of waste water, recbmation, and reuse
the University Authorities have been able to
increase their daily water supply by over 100 .
Fig 2 shows the steps of Treatment Process
.f~r treating the waste water, reclamation, and reuse
for different uses.
. .
In the Secondary Treatment of the waste
water along with die Conventional Activated Sludge
System (CASS), Membrane Bio Reactor (MBR)
Technology is used for getting higher grades of
reuse water.MBR is an advanced treatment process
that combines biological treatment and membrane
filtration to achieve high rate removal of Suspended
Solids aswell as other pollutants removal. Aeration
is used for membrane cleaning, which prevents
sludge blockage by the vibration of membrane.
The treatment system is as described below
Unit 1: Biological unit followed by Biological
Aeration Process (AO +) coagulation, sedimentation,
filtration - Normal quality reclaimed water about
1500 m3/day, used for road washing and gardening.
Unit 2: BiologicaVBiochemical Anaerobic Process
(A20) followed by MBR for producing high quality
reclaimed water for Landscaping, lake
replenishments,..and toilet flushing the quantity
reclaimed is around 2000 m3/day.
Thereby the total daily water being supplied
after implementation of this treatment of waste
water is
3000 + 1500 + 2000 = 6500 m3/d
Thereby earning revenue out of it, which
compensates to some extent the capital cost invested
in installing the system. Moreover from the annual
revenue earned by supplying treated waste water
to the farmers will bring down the operation and,
maintenance costs.
The only disadvantage of MBR is it is costly
compared to the conventional units. However
looking to the high quality of the treated effluent,
the same can be supplied to the farmers who grow
vegetables, fruits, maize, and cotton etc., Thereby
earning revenue out of it, which can compensate to
some extent the capital cost invested in installing
the system. Moreover from the annual revenue
earned by supplying treated waste water to the
farmers will bring down the operation and
maintenance costs.
.
Summary and Conclusion:
.
The fresh water depletion and the drinking
water crisis in many Indian towns and cities
are becoming serious and alarming.
It is time that our planners and experts in
the field of Water Sector show concern about
the situation, and steps in this direction.
Reducing leakages in transmission mains,
distribution lines are necessary to increase
the quantum of water received actually by the
public.
Construction of RWH structures has to be
made mandatory, and implemented strictly.
Construction of dykes, check bunds,
percolation trenches, contour trenches,
recharging c.f existing tube wells etc., which
.
.
.
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2550 M3/DAY
~
~
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I I ,
.SOURCE
LOSS 60 MJ/DAY
LOSS 50
MJ/DAY
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FIGURE
-1
3000
M3/DAY
INSTiTci';'i'6N
FRESHWATER
~
I
I
I
I
I
1- - - - - -
600 M3/DAY
A
I
I
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~
.1
COLLECTABLE 3800 M3/DAY
WASTEWATER TREATMENT
RECALAMA TION
MBR
1960 M3/DAY
HIGH QUALITY
TREATMENT. RECLAMATION AND REUSE
OFWASTE WATER FOR DIFFERENT
USES
RECOVERABLE
1250
M3/DAY
we
1300 M3/DAY
660 M3/DAY
~ ':)
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N.Roy
[ PRETREATMEN~
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Screening
Cansf Rags f5ticks f Plastic bags
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Sand, Pebbles
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Sludge, Fat, Grease
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rimary
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'SE.CbNDARY...TREATMENT
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Organic matter
Effluent reused for
Conventional undergoes change Effluent sent to public parks
Activated
--to
of character, due to
-+ surface aerated
..
watering
Sludge
biologicaloxidation
basins
gardening
and nitrification
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