JournalSoc.,
of Indian
Resources
Society,
J. Indian Water Resour.
Vol.Water
33, No.
3, July,
2013
Vol 33, No. 3, July, 2013
A SHORT SCREENING STUDY ON WATER QUALITY OF INDIAN RIVERS
AND LAKES
A.A. Kazmi1, Akansha Bhatia1, Azfar Shaida1, Meena Sharma1,
Markus Starkl2 and R. C. Trivedi3
ABSTRACT
As a crucial subsystem of urban environment, urban rivers and lakes offer many kinds of ecological services which benefit the city dwellers.
However, with the growing pace of urbanization and rapid development of economy, urban water pollution problems are becoming critical
every hour. In order to get an overview of the current water quality, a short screening study on various urban rivers and lakes has been
carried out across the country. The aggregate pollution index was assessed in terms of NSF WQI. The condition of most of the urban rivers
and lakes are not satisfactory, mainly due to pollution by untreated wastewater. Therefore, it is need of the hour to make provisions for
wastewater treatment to meet required water quality targets. A watershed management approach is suggested as most suitable instrument to
achieve such an objective. This is a significant task for India, which cannot be achieved in a short period of time, henceforth, a mixed
approach comprising of short term (Advanced on-site systems) and medium term (decentralized systems) along with long term (centralized
systems) targets need to be adopted for 100% wastewater treatment in urban and peri-urban areas.
Key words: Water pollution, Urban rivers, Lakes & Jheels, Water quality index.
INTRODUCTION
Water security is emerging as an important and vital issue for
India. Many Indian cities are experiencing moderate to severe
water shortages due to implicit effects of agricultural growth,
industrialization and urbanization. These shortages would be
further aggravated by population stress and irrigation
requirements that are major factors related to water insecurity.
India's population is around 1.21 billion as on 1st March, 2011.
The population of India is expected to stabilize at around 1,640
million by the year 2050. As a result, gross per capita water
available will decline from 1,820 m3/ yr in 2001 to as low as
1,140 m3/yr in 2050. Total water requirement of the country
for various activities round the year 2050 has been estimated to
1,450 km3 /yr. This is significantly more than the current
estimate of utilizable water resource potential (1,122 km3/yr)
through conventional development strategies. Therefore, when
compared with the availability of approximately 635 km3/yr at
present, the water availability around 2050 needs to be almost
trebled (CWC, 2011).
The first-ever water pollution audit in India carried out by the
Comptroller and Auditor General (CAG) has found several
legislative, administrative and institutional lacunae in the way
that the issue of water pollution is dealt with by Indian states
and the Central government. The audit said that despite 27
years of implementation of the programmme to control
pollution, water in major rivers is critically polluted (CAG,
2011). Therefore, it could be inferred the alarming situation for
most of the 14 major, 44 medium and 55 minor river basins in
India (CPCB,2009).
The planning of the two centrally sponsored schemes of
National Lake Conservation Plan (NLCP) and National River
Conservation Plan (NRCP) was flawed, as the inclusion of
1.
Department of Civil Engineering, IIT Roorkee
Corresponding Authors (E-mail: [email protected])
2.
University of Natural Resource & Life Sciences (BOKU),
Vienna, Austria
3.
Former Additional Director, Central Pollution Control
Board, Ministry of Environment & Forests, Government of
India
Manuscript No.: 1351
rivers and lakes in the programmes was not based on
comprehensive surveys to assess pollution levels across the
country. Also, the concerns related to water pollution have
been adequately addressed in the National Water Policy and
National Environment Policy in India, both at the Central and
the State level. However, the provisions for generation of
resources for preventing pollution, treatment of polluted water
and ecological restoration of polluted water bodies are not
adequate. According to the CAG, with the exception of Ganga
in certain stretches, all the other rivers test-checked by it i.e.,
Ganga, Yamuna, Gomti, Godavari, Musi, Cauvery, Cooum,
Mahananda, Khan, Kshipra, Vaigai, Chambal, Rani Chu,
Mandovi, Sabarmati, Subarnarekha, Bhadra/Tungabhadra,
Pennar, Pamba, Betwa, Krishna, Sutlej etc., continue to be
plagued by high levels of organic pollution, low level of
oxygen availability for aquatic organisms and bacteria,
protozoa and viruses which have faecal-origin and which cause
illnesses(CAG, 2011). In relation to lakes across the country,
many of them have disappeared due to illegal filling, dumping
of waste and drying up of their catchment areas which have
been reclaimed for uses like urbanization. Most of the lakes in
India are under threat from nutrient overloading, which is
responsible for their eutrophication and subsequent choking up
from the weeds proliferating in the nutrient-rich water. The
reason behind is the degrees of pollution and natural
purification are measurable physically, biologically and
chemically (Longe and Omole, 2008).
Accurate and timely information on the quality of water is
necessary to shape a sound public policy and to implement the
water quality improvement programmes effectively and
efficiently. One of the most effective ways to communicate
information on water quality status and trend is by using
indices. Water quality index (WQI) is commonly used for
summarizing water quality and comparing water quality of
different water bodies. It is defined as “a rating reflecting the
composite influence of different quality parameters on the
overall quality of water”. The WQI is a dimensionless number
with values ranging from 0 to 100. A higher index value
represents a good water quality (Cude, 2001; Pandey and
Sundaram, 2002). This short screening study is an attempt to
28
32 J. Indian Water Resour. Soc., Vol. 33, No. 3, July, 2013
assess water quality of selected rivers and lakes across India on
the basis of WQI values in regard of physico-chemical and
bacteriological parameters and provision of sustainable
solutions to improve the water quality status of these water
bodies.
CURRENT WATER QUALITY OF INDIAN
RIVERS AND LAKES
In order to derive WQI for different water bodies selected
during the study, water quality assessment was carried out as
follows:
Sampling Sites
River water sampling
Water samples were collected at the stretches of various urban
rivers basins viz., Alkananda (langsi) (Joshimath, Uttarakhand,
30°29'32.77"N
79°28'31.50"E),
Ganga
(Haridwar
(29°56'36.01"N 78°10'2.40"E) and Rishikesh (30° 4'13.39"N
78°17'8.66"E) Uttarakhand), Ganga (Kanpur(26°27'19.95"N
80°23'8.48"E) and Allahabad (25°25'3112"N 81°52'50.16"E)
Uttar Pradesh), Sutlej (Ludhiana 31° 0'0.00"N 75°49'24.35"E,
Punjab),
Yamuna
(Okhla
barrage
(28°32'38.34"N
77°18'53.47"E) Delhi), Sabarmati (Dharaoi 22°59'37.16"N
72°33'28.70"E, Gujarat) , Mula-Mutha (Pune 18°32'35.94"N
73°52'59.62"E,
Maharashtra),
Adyar
(13°1'18.00"N
80°12'41.00"E, Chennai) and River Coovum basin
(13°4'17.74"N 80°16'32.56"E , Chennai).
Lakes sampling
Water samples from different points of lakes/jheels such as
Naini Lake (Nainital (29°23'09.72" N
79°27'34.88" E),
Uttarakhand), Sanhit sarovar(N 29.9673, E 76.8362
Kurukshetra, Haryana), Man Sagar Lake (26°57´21.08” N
75°50´58.18” E Jaipur, Rajasthan), Ambazari Lake(21° 7’
30.49” N 79° 2’ 25.51” E Nagpur, Maharashtra), Phutala Lake
(21° 9’13.36” N
79° 2’ 37.91” E Nagpur, Maharashtra),
Gandhi Sagar Lake (21° 8’ 40.57” N, 79° 6’ 3.06” E Nagpur,
Maharashtra), Gorewada Lake(21° 11’26.09” N 79° 2’ 10.62”
E Nagpur, Maharashtra),
Ulsoor lake(12°59'5.02"N
77°37'19.07"E
Bengaluru, Karanataka),and Bellandur
lake(12°56'4.58"N
77°39'59.22"E Bengaluru, Karanataka)
were collected.
Sampling and Experiments
Grab samples were collected from the selected sampling
locations at non- monsoon sampling period, i.e., from February
to April, 2012 (Table 1& 2). The date of Alaknanda River and
Sannihit Sarovar, Kurukshetra has been collected in Feb 2009
and May 2010 for all samples were labeled properly, preserved
at 4°C and brought to the laboratory with necessary
precautions. All the samples were analyzed following standard
methods (APHA, 2005). Some parameters like temperature,
pH, Secchi depth (m) and dissolved oxygen were measured on
site. The samples were analyzed for following
physicochemical parameters:
Total Alkalinity (mg/L), Turbidity (NTU), Total Dissolved
Solids (mg/L), Total Suspended Solids (mg/L), Electrical
conductivity (µmho/cm), Biochemical Oxygen Demand (BOD)
(mg/L), Chemical Oxygen Demand (COD) (mg/L), total
Kjeldahl Nitrogen(mg/L), Ammonical-nitrogen (mg/L),
Nitrate-nitrogen(mg/L), Orthophosphorus (mg/L) and Total
phosphorus (mg/L). Bacteriological parameters such as Total
Coliforms (MPN/100mL) and Fecal Coliforms (MPN/100mL)
were evaluated for the samples (APHA, 2005).
Water Quality Index
There are various water quality indices to compare various
physico-chemical and biological parameters such as Bhargava
method, Hortons method, Delphi method etc. (Pandey and
Sundaram, 2002; Chetana and Somshekharr, 1997; Ram and
Anandh, 1996). However most of the indices are based on the
first water quality index developed by Brown et al., 1970,
which was later supported by the U.S. National Sanitation
Foundation (NSF). NSF WQI is an excellent management and
general administrative tool in communicating water quality
information (Samantray et al., 2009). The mathematical
expression for NSF WQI is given by:
NSF WQI = ∑
WiIi
Where,
Ii is the sub index for ith water quality parameters, Wi is the
weight associated with ith water quality parameters and P is the
number of water quality parameters (www.water-research.net).
During the study, eight parameters were considered for
calculation of water quality index: Temperature, pH, electrical
conductivity, NH3-N, NO –N, TDS, TP and FC.
3
RESULTS
The physico-chemical and microbiological results for rivers
and lakes are quoted in Table 1 and 2. Aforementioned results
of this short screening study are based on grab sampling which
encompasses most of the Indian urban cities that revealed the
status of country’s Rivers and Lakes (Table 1and 2). Physicochemical parameters such as temperature ranged from 10 °C to
22 °C for water bodies. The temperature of water is an
important parameter which affects the chemical reactions in
aquatic ecosystem. pH is important to quantify the health of a
river or lake varied from 6.6- 8.7 during the study period. The
total Alkalinity ranged from 120 mg/L to 450 mg/L. Higher
alkalinity at some sampling stations might be due to high
carbonates and bicarbonates in the water. Total Dissolved
Solids (TDS) ranged from 260 mg/L to 440 mg/L with an
exception of greater values for river Coovum and Bellandur
Lake, this could be due to tidal effects on these water bodies.
The excessive TDS generally affects the portability.
DO is a very important indicator of a water body’s ability to
support aquatic life. The D.O. of all rivers & lakes was in
accordance with the desired limit prescribed by CPCB except
Yamuna (nil), Coovum (0.3 mg/L) and Bellandur lake (2.3
mg/L). Rivers with low oxygen levels often cause obnoxious
odor because of hydrogen sulphide and other anaerobic gases
produced in absence of oxygen. In addition, low DO
concentrations also mobilize the trace metals (Murphy, 2007).
BOD values ranged from 5.2 mg/L to 34 mg/L for southern
rivers. High BOD results in reduced levels of DO, with
potentially dangerous implications for the river’s biodiversity.
Elevated BOD values could be attributed organic pollution
resulting from discharge of partially treated or untreated
wastewaters. The high nitrate levels facilitating high plant
growth leading to eutrophication. Ammonical-nitrogen values
33 29
J. Indian Water Resour. Soc., Vol. 33, No. 3, July, 2013
Table 1: Characteristics of Indian Rivers
Parameters/Sampli
ng period
Alkananda
(Joshimath,
February
2009)
Ganga
(Rishikesh,
February
2012)
Ganga
(Haridwar,
February
2012)
Ganga
(Kanpur,
March
2012)
Ganga
(Allahabad,
March 2012)
Sutlej
(Ludhiana,
March 2012)
Yamuna
(Delhi,
March 2012)
Sabarmati
(Gujarat,
February
2012)
Mulamutha river
(pune,
March
2012)
Adyar
(Chennai,
March
2012)
Coovum
(Chennai,
March
2012)
Temperature (°C)
11.5
19.8
17.8
17.3
17.2
17.9
21.4
15.3
19
22
22.5
pH
8.7
7.40
8.12
7.94
7.66
7.5
-
7.1
7.1
6.9
6.61
Alkalinity (mg/L)
190
130
124
145
152
126
346
152
160
450
420
Turbidity(NTU)
0.9
2.1
3.7
4.21
7.4
27.8
76.6
13.5
31.5
36.4
49
TDS(mg/L)
-
122
90.8
263
305
228
258
1015
357
1067
2100
DO(mg/L)
9.5
9.4
10.3
-
-
8.4
0
9.1
-
-
0.3
BOD(mg/L)
1.8
0.5
0.4
5.2
5
3.8
34
34
34
23
-
COD(mg/L)
8
12.5
17.5
21
23
28.4
120
44
48
68.5
85.4
TSS(mg/L)
19
5
6
13
23
50
170
109
133
60
120
TS(TSS+TDS)(mg/
L)
-
127
96.8
276
328
278
428
1624
490
1127
2220
TKN(mg/L)
-
1.9
1.1
-
-
-
-
-
24
34.4
28.9
NH4-N(mg/L)
1.1
0.1
0.2
1.2
1.5
6.7
31.9
32
4.6
30.8
34
NO3-N(mg/L)
3.3
1.2
0.8
3.4
4.1
1.8
10.3
3.7
1.8
8.0
6.5
Orth-P(mg/L)
2
0.2
1.0
0.4
0.2
0.8
5.6
0.4
5.4
5.8
0.6
T-P(mg/L)
-
0.8
1.6
0.6
0.8
1.0
6.4
1.8
2.4
11
1.4
Nil
Nil
nil
4,300
1500
150,000
2300
430
230000
930
930
30
Fecal
Coliforms(MPN/10
0mL)
32 30
J. Indian Water Resour. Soc., Vol. 33, No. 3, July, 2013
Table 2: Characteristics of Indian Lakes & Jheels
Naini LakeNainital
Sanhit
Sarovar
Man Sagar Lake
Ambazari Lake
Phutala Lake
Jaipur
(Rajasthan,
March 2012)
Nagpur
(Maharashtra,
March 2012)
Nagpur
(Maharashtra,
March 2012)
Gandhi Sagar
Lake
Gorewadalake
Ulsoor Lake
Bellandur
Lake
Nagpur
(Maharashtra,
March 2012)
Bengalur
(Karanataka
,
March2012)
Bengaluru
(Karanataka,
March2012)
28.8
26.8
22.5
22
7.8
7.7
7.7
-
-
146
210
130
130
101
429
35.8
4.0
1.1
1.9
1.3
151.0
31.8
0.3
0.15
-
0.60
0.45
-
0.15
0.03
440
-
1840
222
263
267
298
257
816
DO(mg/L)
9.9
-
15.4
9.6
7.8
7.5
8.9
7.25
2.3
BOD(mg/L)
2
14.5
21
34
24
13
8
6
38
COD(mg/L)
9
24.6
147
59
77
56
18
14.7
97
TSS(mg/L)
7
12
100
47
34
12
10
37
20
TKN (mg/L)
-
-
-
-
-
-
-
10.0
25
NH4-N(mg/L)
2.2
4.3
0.7
1.1
1.1
1.3
1
3.7
24.6
NO3-N(mg/L)
4.6
1.5
11.3
3.3
3.5
4.5
2.8
6.6
6.1
Ortho-P(mg/L)
0.2
-
0.2
2.0
1.4
1.4
0.2
0.6
1.6
T-P(mg/L)
0.2
0.6
1.8
2.3
1.9
2.2
0.7
1.8
5.6
Nil
Nil
700
NIL
150
NIL
NIL
430
23000
Parameters/ Sampling
date
(Uttarakhand,
March 2012)
Kurukshetra(Haryana,
May 2010)
Temperature (°C)
18.8
31.3
21.8
28.4
26.8
pH
8.0
8.8
8.0
8.2
Alkalinity (mg/L)
200
71
366
Turbidity (NTU)
0.34
18.5
Secchi Depth (m)
1.50
TDS(mg/L)
Nagpur
(Maharashtra,
March 2012)
Fecal
Coliforms
(MPN/100mL)
31
33 J. Indian Water Resour. Soc., Vol. 33, No. 3, July, 2013
were higher for rivers such as Yamuna, Aadyar, Coovum and
Lake Bellandur due to discharge of untreated wastewater.
Ammonia depletes DO in water due to its oxidation. The level
of Fecal Coliforms (FC) in water indicates its suitability for
different human uses. The FC concentration for north-western
and southern rivers was higher than the others. Figure 2 and 3
depicts the status of rivers and lakes in terms of WQI. None of
these sampling stations showed excellent WQI i.e, 90-100,
which is very common in developed countries. The main
reason for such a low WQI in Indian Rivers and Lakes is the
high dissolved and suspended organic matter, nutrient and
coliforms.
CAUSES OF HIGH POLLUTION
Direct Causes
The main reason of such a high dissolved and suspended
organic matter, nutrient and pathogenic pollution is the
indiscriminate discharge of domestic wastewater. Industrial
pollution is also a contributing factor but only in limited
stretches of certain rivers and lakes of the country. There are
deep underlying factors involved in the generally low coverage
of sewerage services in urban areas. The rapid pace at which
urbanization is happening, combined with the low income
levels of a large proportion of the population, is a basic factor.
Much of the expansion of residential and industrial areas is
uncontrolled. Many cities continue to suffer from high inflows
of migrants from their rural hinterlands. Uncontrolled housing
and, worse still, developments of illegal squatter colonies that
often line the waterways running through urban areas
constitute a major problem for city administrators. Under
warm equatorial conditions and especially during the summer,
high temperatures add to the problem of rapid putrefaction in
polluted water. The presence of large amounts of garbage and
other blockages reduces the natural flow of water through
drains, canals, streams, and rivers, leading to stagnation. It is
common to see water in these channels turning green and
turbid because of algal bloom.
Indirect Causes
Most cities in the country suffer from a lack of financial and
technical resources to undertake the construction of large-scale
centralized sewerage systems. Even though the major cities,
where the wealth of the nation is concentrated, would have the
resources to build and maintain an adequate sewerage system,
they mostly do not use these resources. The problem appears to
be one of political wills; sanitation does not directly generate
revenue and it is not a visible benefit even for those urban
dwellers that have their homes connected to a public sewer. It
is also understandable that more attention is given to the
provision of safe water through the construction of watersupply systems, which cost a tenth of the investment for a
sewerage system and have more visible benefits. Unless drastic
measures would be taken the situation would be out of control.
WATERSHED MANAGEMENT APPROACH
(WMA) AS SOLUTION
From an environmental perspective the overarching goal of
water management should be the clean up of polluted rivers
and lakes to restore a good water quality. Therefore, a
watershed management approach is a most suitable
management instrument for wastewater pollution control to
achieve this goal (Kazmi & Furumai 2005). WMA allows
finding the optimal wastewater management solution across
administrative boundaries and therefore avoiding the often
observed small scale, piecemeal approach to the problem.
A watershed can be defined as the entire catchment area that
ultimately drains into a particular watercourse or body of
water. To be effective the complete country has to be assigned
to watersheds. Then, the current water quality baseline has to
be documented for each watershed and appropriate water
quality targets established. A watershed is smaller than an
entire river basin and therefore it may be easier to manage than
an entire river basin. Each region should make a watershedbased plan for water pollution control. Four main features are
typical of the watershed approach: (1) identifying and
prioritizing water quality problems in the watershed; (2)
participatory planning to involve all stakeholders and users in
problem identification and establishment of suitable water
quality targets; (3) identification of most effective strategies to
reach the water quality standards and coordinating activities
with other agencies; and (4) measuring success through
increased and more efficient monitoring and other data
gathering.
Tackling wastewater management from a watershed
management approach helps to identify the most cost-effective
pollution-control strategies to meet clean water goals, to
achieve the best balance among efforts to control point-source
pollution and non-point pollutant run-off as well as to protect
drinking water sources and sensitive natural resources such as
wetlands. In particular, the WMA allows establishing suitable
short, medium and long term strategies. As achieving the final
target water quality across India is an immense task which
cannot be achieved in a short period of time, a mixed approach
of short term (Advanced on-site systems) and medium term
(decentralized systems) along with long term (centralized
systems) targets needs to be adopted for 100% wastewater
treatment in urban and peri-urban areas. Nevertheless, large
treatment plants with more than 20 MLD capacity is cheaper in
overall cost economics, as expert manpower, laboratory,
workshop storage will be less. Larger plants are easier to
operate, maintain and keeping track of performance standards.
Further, a WMA allows for better coordination of wastewater
management with overall watershed management which is
required for finding cost-effective solutions. One example of a
watershed management plan is the Tokyo Metropolitan
Government’s Master Plan for Water Cycle (Figure 4) which
illustrates the water balance of the city(Tokyo Metropolitan
Government, 1999). Such visualization nicely shows the effect
of water reuse and recycling on the overall water balance of
the city.
In addition to the Watershed Management Approach there
should be strong emphasis on recycling of wastewater by
making effluent discharge law more stringent with mandatory
nutrient removal. The stringent standards can be easily met by
implementing
advanced/tertiary
wastewater
treatment
technologies which would give BOD < 10 mg/L, TSS < 10
mg/L, TN < 10 mg/L, TP < 1-2 mg/L so that the treated
wastewater can be reused effectively. By selling treated water,
ULB’s can make revenue and meet O&M expenses, reducing
life cycle cost which they are anyway incurring today. When
recycling and selling water is focused primarily, ULB (the
32 J. Indian Water Resour. Soc., Vol. 33, No. 3, July, 2013
operator) is more concerned about the quality of discharge as
someone is recycling the water and if the quality is not good
there is a loss in revenue. Today as the treated wastewater goes
for disposal, proper attention is not being given to the quality
of discharge. Incentives can be provided to lower power or less
land or giving better output quality from the plant Or higher
percentage of funding (say 90 % instead of present 70 %),
award or recognitions should be given for better functioning
plants.
5.
Cude, C., 2001. Oregon water quality index: A tool
for
evaluating
water
quality
management
effectiveness. J. of the American Water Resources of
Association, 37(1), 125-137.
6.
Joshi, D.M., Kumar, A. and Agrawal, N., 2009.
Studies on physicochemical parameters to assess the
water quality of river ganga for drinking purpose in
haridwar district. J. Rasyan Chem., 2, 195-203.
CONCLUSION
7.
Kazmi, A. A. and Furumai, H., 2005. Sustainable
urban wastewater management & reuse in Asia.
International Review of Environmental Strategies
Journal. 5(2), 425-448.
8.
Longe, E.O. and Omole D.O., 2008. Analysis of
pollution status of River Illo, Ota, Nigeria.
Environmentalist, 28, 451-457.
9.
Murphy, S., 2007. General Information on Dissolved
Oxygen. www.bcn.boulder.co.us/basin, retrieved on
27 September 2007, University of Colorado at
Boulder, Colorado.
Aforementioned results revealed that a lot more efforts are
needed to make wastewater management sustainable in the
rapidly growing cities of developing India. A Watershed
Management Approach can help to find optimal short, medium
and long term strategies. Experiences and innovations from
around world offer a range of solutions to the existing
problems, if only the resources and, more importantly, the
political will can be found. There should be strong emphasis
on recycling of wastewater by making effluent discharge law
more stringent in terms of BOD and TSS with mandatory
nitrogen and phosphorus removal. Stringent standards can be
easily met by implementing high performance technologies
which are able to give BOD < 10 mg/L, TSS < 10 mg/L, TN <
10 mg/L, TP < 1 mg/L so that the treated wastewater can be
recycled directly for non-potable reuse. To support decision
making on which technologies are suitable for which
circumstances across India, a good documentation and
thorough evaluation of existing technologies is required such
as conducted under the EU-DST funded SARASWATI
project. The GOI should encourage operators of existing STPs
to provide access to their data to facilitate such evaluation for
the benefit of India.
REFERENCES
1.
2.
American Public Health Association, American Water
Work Association and Water Environment Federation
(APHA/AWWA/WEF), 2005. Standard methods for
the Examination of water and wastewater. 21st
Edition, Washington, D.C.
Bhardwaj, R.M., 2005. Water quality monitoring in
India- Achievements and constraints , IWG-Env,
International Work Session on Water Statistics,
Vienna, June 20-22.
3.
CAG report. Water in India's rivers remains critically
polluted. India Water Review : December 19, 2011.
4.
Chetana, S.A. and Somashekhar, R. K.,1997.
Evaluation of water quality index of the river Cauvery
and its tributaries. Current Science (Current Science
Association and Indian Academy of Science,
Bangalore), 72(9), 640-646.
10. Pandey, M. and Sundaram, S.M., 2002. Trend of
water quality of river Ganga at Varanasi using WQI
approach. International Journal of Ecology and
Environmental Science, New Delhi: International
Scientific Publications, 28, 139-142,.
11. Ram, K.S. and Anandh, H., 1996. Water quality index
of some
Indian rivers, Indian Journal of
Environmental Health, NEERI, Nagpur,38(1),21-34.
12. Samantray, P., Mishra, B.K., Panda, C.R. et al., 2009.
Assessment of Water Quality Index in Mahanadi and
Atharbanki rivers and Taldana Canal in Paradip
Area, India. Hum Eco. 26 (3), 153-161.
13. Tokyo Metropolitan Government,1999. Mater Plan of
Water
Cycle
[http://www.metro.tokyo.jp/INET/KEIKAKU/SHOUS
AI/7094G100.HTM].
14. Water Quality Monitoring. Last Page Update–
Monday April 23, 2007. Retrieved July 10, 2007, from
http : // bcn.boulder.co.us / basin / data / BACT / info/
DO.html.
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