INTERMITTENT WATER SUPPLIES: WHERE AND WHY

THEY ARE CURRENTLY USED AND WHY THEIR FUTURE

USE SHOULD BE CURTAILED

By:

Shrihari Sridhar

A thesis submitted in conformity with the requirement for the Degree of

Master of Applied Science Graduate Department of Civil Engineering

University of Toronto

© Copyright by Shrihari Sridhar 2013

ii

Abstract

INTERMITTENT WATER SUPPLY: ORIGIN, CONSEQUENCES

AND SOLUTION

By

Shrihari Sridhar

Department of Civil Engineering

University of Toronto

2013

Though water is the most essential element of life in most developing countries clean

drinking water is supplied intermittently to consumers. Municipalities are often under the

impression that intermittent supply is an ideal measure to conserve water. With over a billion

people grappling with deteriorating infrastructure and water scarcity, it is impossible to

neglect the effects of intermittent supply. It is essential to examine the origin of the problem,

quantify the effects or consequences and then provide feasible solutions.

Hence, this thesis provides a comprehensive review of the existing condition of water supply

systems in developing countries but more importantly, examines the causes of the

intermittency and highlights the significant economic incentive that could be achieved by

maintaining a continuous supply system. Finally the thesis concludes with a series of feasible

solutions including short-term and long-term plans that would assist in a complete migration

towards 24-hour supply.

iii

Acknowledgement

It is a pleasure to thank the many people who made this thesis possible.

I would like to express my deepest gratitude to my supervisor, Dr. Bryan Karney for his

continued support, devotion, patience, consistent guidance and for instilling in me the ability

to motivate myself to achieve results.

My thanks also go to Dr. Jennifer Drake for her helpful comments as a second reader. My

sincere thanks to those who showed interest in my work and gave me some valuable inputs,

especially my colleague Mr. Ahmad Malekpour.

I would like to thank my parents for their financial support and consistent encouragement

without which I would not have been able to continue with my graduate studies.

Finally and most importantly, I thank God for granting me the wisdom, knowledge, sound

mind, good health and for supplying all my needs to produce this work.

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Contents

Abstract

Acknowledgement

List of Figures

List of Tables

1. Introduction

1.1. Importance of this Study........................................ 04

1.2. Objectives....................................................... 05

1.3. Organization.................................................... 06

2. Problems Resulting in an Intermittent Supply

2.1. Water Scarcity Issues............................................ 09

2.2. Economic Restrictions and reducing hydraulic capacity........ 11

2.3. Improper Resource Management................................ 13

2.4. Summary......................................................... 14

3. Consequences of an Intermittent Water Supply System

3.1. Improper Water Distribution and Pressure management........ 15

3.2. Coping Costs.................................................... 17

3.3. Overexploitation of Groundwater............................... 20

3.4. Unhealthy Practices and Water Losses.......................... 21

3.5. Constraints to meet fire flow needs with the present system.... 22

3.6. Increasing Costs and Rising Energy requirements............... 22

3.6.1. Ageing Infrastructure and High Energy Costs............ 22

3.6.2. Pipe Breakage (Line Filling).............................. 27

3.6.3. Air Entrainment .......................................... 29

3.7. Water Contamination............................................ 31

3.7.1. Water stagnation in pipes and private tanks.............. 31

3.7.2. Water Stagnation in Pipes and Tanks....................... 35

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3.7.3. Privatization............................................... 37

3.7.4. Summary.................................................. 38

4. Detailed analysis of the possible solutions

4.1. Immediate steps to move towards a continuous supply......... 40

4.1.1. Water conservation........................................ 40

4.1.2. Water Demand Management.............................. 41

4.2. Pressure Management and Leakage Control..................... 43

4.3. Improved Metering and Billing Procedures..................... 45

4.4. Model Resource Management Strategies and Long Term Plans. 47

4.5. Model Strategies................................................ 51

4.6. Summary........................................................ 52

5. Case Study of Bangalore and Mumbai

5.1. Comparative Energy and Cost Analysis of Continuous and Intermittent Supply

Systems – Mumbai, Case Study.................................. 53

5.1.1. System Parameters and Projected Demand................ 56

5.1.2. Consequences of Pipe ageing on Transmission (Pumping) Energy loss 58

5.1.3. Analysis of the Results..................................... 68

5.2. Sample Study-Bangalore, India................................... 74

5.3. Summary.......................................................... 76

6. Conclusion and Future research opportunities..................... 78

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List of Figures

3.2.1. Estimated Cost Comparison.................................... 18

3.6.1. Water Distribution Energy use Comparison..................... 23

3.6.2. Pipe Wall Corrosion........................................... 25

5.1. Mumbai Water Distribution Plan................................. 54

5.2. Water Conveyance (Pumping) Cost Comparison.................. 68

5.3. Percentage Loss in revenues..................................... 69

5.4. Pipe Repair Cost Comparison.................................... 71

5.5. Estimated Cost Saving........................................... 72

5.6. Pipe Repair Energy Consumption Comparison.................... 73

5.7. Ratio of Energy Use (IS:CS) .................................... 73

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List of Tables

3.7.1. Peak factor Comparison between Intermittent and Continuous Supply Systems. 33

4.1. Monthly Water Consumption Block Rates....................... 46

5.1. Water Supply and Demand Projection........................... 58

5.2. Per-capita Water Consumption distribution...................... 75

1

CHAPTER 1

Introduction

Water for human and urban use is often transported from source to domestic and industrial

users through a network of pipes of various diameters. Drinking water is collected from one

or more natural source water resource such as a lake, river or aquifer and is conveyed to a

treatment facility. Additional facilities such as pumping stations and storage reservoirs are

required to reliably pressurize the water through a pipe network until the water finally

reaches the consumer. A complex system such as this is in place to supply clean drinking

water to the consumers continuously throughout the day. However in some developing

countries, the consumers will have access to drinking water for less than 24 hours or even

from a few hours to few minutes a day. This thesis examines the consequences of resorting

to intermittent water distribution systems in developing countries with a focus on its impacts

on the distribution system and how the society responds and copes with a rationed service.

The work in this thesis is in part summarized in a paper “A Selective Literature of

Intermittent Water Supply: Problems and Solutions”, which is under review in the Journal of

Water, Sanitation and Hygiene for Development.

A water supply is said to be intermittent when the water to an area is regularly/irregularly

provided through piped networks for less than 24 hours a day. Though basic issues related to

water scarcity and intermittent supply are not part of popular consciousness in developed

countries, their effect is truly global as this issue affects over a billion people worldwide.

Intermittent water supply systems are found mainly in newly developing countries.

including most of the countries of South Asia and Latin America (Vairavamoorthy, 2007).

2

South Asia is estimated to supply water to at least 350 million people for as little as a few

hours a day, and nearly all water supply systems in Indian cities are intermittent. In Latin

America alone, more than 50 million inhabitants in 10 of its major cities receive rationed

water supply (Vairavamoorthy, 2007). No city in India has a continuous water supply (WSP,

2009) and even in major cities of India, water supply is as low as 1 hour a day or less and 2-3

hours of supply is considered to be good. Currently, some 30 countries are considered to be

water stressed. It is predicted that by 2050, the number of water scarce countries will likely

approach 35 (Vairavamoorthy, 2007). Jordan, for example, has a severe water shortage

problem. The drinking water available per capita is less than 100 lpcd (litre/capita/day)

(Vairavamoorthy, 2007).

Urban population growth is among the most central concerns to meeting future water needs,

particularly in developing countries. One third of the 9 million residents in western Manila,

Philippines are not connected to the municipal water system, and over 1 million suffer from

intermittent supply or very low system pressures (Miya, Manila project, 2007). With overall

consumption constantly increasing from limited sources, water boards felt they have little

option but to supply water intermittently. Water demand is increasing at three times the rate

of the world’s population growth, and officials at the 3rd World Water Forum noted that

poverty alleviation is the single most important factor related to meeting that demand

(Environment News Service, 2003). According to official figures from the Water Forum,

around 1.2 billion people lack safe water supply and 2.4 billion live without secure sanitation

(Environment News Service, 2003). India’s population grows by over 1% per year and with

this acute population increase, water scarcity becomes obvious. In Kathmandu, Nepal 5,000

new connections are provided each year despite an inadequate distribution system (McIntosh,

3

2003). According to Western Jakarta water services, 210,000 water connections were added

in the 11 years between 1998 and 2009 (PPP Jakarta water, 2007). The scale of the human,

technical, economic and hydrological problems is immense.

As Vairavamoorthy (2007) shows, the relative increase of water consumption in developing

countries further highlights the need for creative solutions to water scarcity. From 1995 to

2005, water consumption was expected to double in developing countries, with water

demand projected to be essentially flat in developed countries (Vairavamoorthy, 2007). If the

demand drastically increases, a complete system overhaul will be necessary: increased

hydraulic capacity will require more high power equipment to be installed, new water

sources to be found and tapped, and all related infrastructure improved. All such factors

require substantial capital, which in most cases developing countries cannot afford to invest,

and thus intermittent supplies are adopted as a relatively inexpensive water conservation

technique and seemingly safe option. Table 1.1 summarises briefly the advantages and

disadvantages of intermittent flow.

Perceived advantages of Intermittent Water Supply:

A convenient Water saving technique

A good conservation technique for a short term as it doesn’t need any additional

infrastructure.

Disadvantages of Intermittent Water Supply:

Insufficient pressure at the consumers end,

Higher possibility of contamination

Additional costs (coping costs) incurred by the consumers

4

Inequitable Distribution of water

Unhealthy practices that lead to unnecessary wastage.

Increase in leakages which in turn worsens the system

Major disadvantage during Fire accidents

Metering problems

More frequent water hammer issues

Increasing exploitation of Ground water will cause environmental problems in the

long run.

1.1. Importance of Current Study

This study makes an important contribution towards relating causes and effects of

intermittent water supply. The effects have however been discussed in the past through

various reports and studies as it manifests itself as hindrances to our everyday life. For

instance, contamination of drinking water, deteriorating water quality and transient pressure

conditions might manifest in the form of a disease outbreak or a watermain break. Though

plethora of evidence was found in the literature reviewed that indirectly pointed towards

intermittent supply as the prime cause of such effects, hardly any attempt was made in other

works to knit all the causes and effects together to present a complete picture of state of

water supply in most parts of the developing world. Simply identifying the origin of a

problem does not provide enough motivation to find an optimum solution unless the

magnitude of its consequences is well documented and quantified. The same has been the

case with intermittent supply. For instance, Totsuka et. al. (2004) analyze the origin of

intermittent supply and express the need to migrate towards a 24-hour supply but finally end

up justifying the need to implement a new set of design guideline to operate distribution

5

systems intermittently. However their objectives are partly justified as the existing

intermittent systems are designed to be operated continuously because no guidelines were

available specifically for the design of intermittent systems. This approach of dealing with

intermittent supply is understandable as there are insufficient studies that report the

magnitude of the consequences. For instance, results of a study reported by Charalambous

(2011) were the only information available in the literature reviewed that made a connection

between intermittent supply and the resulting pipe breaks. Similarly, few studies were found

in the literature reviewed that compared the rate of corrosion in an intermittent and 24-hour

supply system. The closest available resource in the literature is the statement, “It is

generally believed that, pipes in an intermittent supply system tend to corrode faster than

pipes in a continuous pressurised system as pipes are alternatively exposed to air and water”,

available in the Sustainable Sanitation and Water Management website (SSWM). As the rate

of corrosion would affect the friction head-loss and ultimately the energy involved in

transmission, a study representing this connection is an important contribution towards

decision making.

Hence this work not only bridges the causes and effects of intermittent supply, but provides

enough evidences to prove that a complete migration towards a 24-hour supply is not only

humanly justified and urgent, but would bring great benefit to infrastructure performance and

longevity.

1.2. Objectives and Organization of this Study

Being one of the foremost issues faced by the developing world intermittent supply needs

utmost attention and careful analysis before any action is taken. India is used as a typical

6

developing country to discuss the real-world implications of intermittent supply. Hence the

objectives of the thesis are several:

1) To identify the factors that contribute to the intermittency in supply,

2) To identify the direct and indirect consequences of Intermittent Water Supply (IS),

3) To quantify the effects of intermittent supply,

4) To perform a comparative study of intermittent and continuous water supply (CS)

systems to assess the possible advantages of a complete migration; and

5) To identify feasible methods and strategies for a complete migration under all

conditions of intermittency.

1.3. Organisation

The structure of the thesis is as follows. The origin of intermittent water supply is discussed

in Chapter 2. As the cause intermittency in supply varies, the origin of the problems have

been categorised and each category is analysed and supported with examples from specific

regions in India.

The consequences of resorting to an intermittent supply system are thoroughly presented in

Chapter 3. A comparative energy and cost analysis between a continuous and an intermittent

supply system is performed and results presented typically measure the net advantage of a

complete migration to a 24-hour supply system. As it is one of the first studies of its kind

various available models and reports were reviewed and compared. Results are presented

through two types of indicators: embodied energy and cost.

Chapter 4 presents some feasible solutions in the form of short-term measure and long-term

strategies that would aid a successful migration to a 24-hour supply. Importance is given to

7

demand side management and water conservation. As water scarcity situation is not new,

some measures that have either been implemented or proposed in the past are presented with

the idea of identifying a possibility to modify them to suit an Indian (or South-East Asian)

scenario. Further the advantages of using reclaimed wastewater are presented with a focus on

net energy benefit. Chapter 5 concludes the thesis by suggesting future avenues of research

based on the results presented in the thesis that could contribute to reliable and sustainable

24-hour water supply for the growing population in the developing world.

8

CHAPTER 2

Origin of Intermittent Supply

The first step in solving a problem is recognising one exists. This chapter hence presents all

crucial factors that lead to, or are said to justify, intermittent supply. Through an extensive

literature review, field surveys and information retrieved from various sources including

personal experiences, discussions and local media, the chapter collects and summarizes a

state-of-the-art understanding of intermittent flow. The common understanding on the reason

behind the intermittency is that the amount of water available is insufficient to meet the

consumer demands. But a little more attention would reveal that intermittency persists even

in places which have abundant fresh water resource. For instance, even though the Indo-

Gangetic plains, home to a billion people in the Indian subcontinent (which covers the

Ganges-Brahmaputra region of Eastern India and Bangladesh) have perennial water source

(in abundance) no city in the region enjoys a continuous water supply. Such realities prove

that apart from absolute water scarcity there are other factors which are either individually or

collectively responsible for the intermittency. The other question is also relevant: to what

extent do intermittent supplies reduce the overall demand for water? Consumers hoarding

large amount of water and discarding them during the next flush simply results in excessive

consumption which contradicts the general belief that intermittent supply reduces overall

water consumption. Hence in the present study the origin has been divided into three main

categories and with the help of real situation in different cities in India, the problems have

been thoroughly examined.

9

2.1. Water Scarcity

Lack of access to a continuous source of clean water is a central problem in a developing

country. Though South-East Asian countries and the Indian sub-continent communities are

blessed with water resources, but are experiencing steeply increasing population and heavy

migration from rural to urban areas. These rapidly shifting urban demographics are creating

the potential for acute local, regional or even national water crisis. Conflicts between

households and neighboring communities to secure water are a common sight even in urban

India. There is a frenzied scramble among thirsty crowds to secure water from (water) trucks

(Krishnan, 2013). Regional water dispute between states is strongly affecting the country’s

agricultural and industrial production leave alone the increasing suicide rates among the

agricultural communities! For instance more than 2,200 farmers in India committed suicide

in the past four years, as water loss and drought drove them deeper into debt (Katakey, et.al,

2013).

The city of Chennai stands as a perfect example of a place grappling with water scarcity. As

against the demand of 1009 MLD, the supply only about 766 MLD with only a part of it

supplied through piped networks (Srivathsan, 2013). A portion of the supply takes place

through water tankers. Over 13,000 tankers that operate in the city mine water from the

surrounding farmlands and the tanker industry is said to be worth over $100 Million

(Srinivasan, 2005). Thus, the acute water shortage is met by removing water from the

neighboring rural areas. The scarcity is mainly due to the two seasonal rivers (Cauvery and

Krishna) which are the primary water sources. However as the neighboring provinces depend

on these rivers as well, Chennai is put in an unsure situation.

10

A similar situation exists in the Indian capital, New Delhi. The city has a demand of around

4200 MLD but is able to supply only around 3150 MLD (Kaur, 2012). Though a large part of

this demand is not met through piped water supply. Around 2 million people in the Indian

capital of New Delhi alone siphon their water from water trucks, then hauling it back to their

shacks where they live with their families (Fishman, 2011).

Bangalore is one of the largest cities in India with a population of over 8.5 million. With a

per-capita consumption of 150 l/day, the city needs 1425 ML of water every day out of

which the industrial consumption is around 50 MLD (TOI, 2013). The City draws 532,000

ML/year of water from Cauvery river, which gets exhausted (or level in the reservoir drops

below the minimum level) with the supply of 1,425 MLD (TOI, 2013). But even with such

efforts the Water Board (BWSSB) is barely able to supply water 2-3 times a week. This is

mainly because around 450 MLD (or 30%) of the pumped water is lost through leaky pipes

(TOI, 2013). In another six to seven years per-capita availability of water in Bangalore may

be as little as 73 lpcd which is less than what is prescribed by the World Health Organisation

(100 lpcd) (TOI, 2013). There are claims that if the scarcity is not addressed soon, by 2023

half the city will have to be evacuated (Sudhir, 2013). Even the Bureau of Indian Standards

(1993) prescribes the per-capita water requirement in a city like Bangalore should range from

150-200 lpcd.

Hence one of the main reasons of intermittency is absolute water scarcity. Rapid urbanisation

is also partly responsible for the scarcity and a primary concern in developing world cities is

the unprecedented population increase, a direct result of rural migration. Between 1950 and

1990 the number of world cities with a population greater than 1 million increased from 78 to

290 and is expected to rise to 600 by 2025 (Vairavamoorthy, 2007). This is hence a clear

11

indication that if the number of cities (and thus the urban population) increases there will

likely be more water scarcity in the future.

2.2. Economic Restrictions and reducing hydraulic capacity

Lack of sufficient financial resources is another of the important factors that contributes to

the intermittency. Finances of the water boards are plummeting and the revenues are

insufficient to meet even the basic expenditures (Mathur and Thakur, 2003). Many

municipalities seem unperturbed about unmetered connections either because it is one of the

crude measures to help the poor or the existing system does not assist in maintaining metered

connections. Also in most Indian cities as the price of water is so low (presently around Rs.

6/KL or $0.1/KL) (Mathur and Thakur, 2003) and penalties for unmetered connections are

not harsh, it is just not feasible to meter the connections. City specific studies of Bangalore,

Chennai and Hyderabad show that the typical price charged for water for residential use is

about Rs. 1.5 ($0.02) per cubic meter which is one tenth of the operating and maintenance

costs (Mathur, 2003). Also, for instance in Gurgaon, until March 2012, over 11000

connections were unmetered. Though municipal authorities issued notification regarding

installation of meters, over 9500 connections remained unmetered till August 2013 (Saini,

2013)

Ray (2009) and Mathur (2001) reported that in India there is a great disparity in metering.

Consumers with metered connections range from as low as 5% in Chennai, 70% in Mumbai,

to 100% in Bangalore. Also a quarter of all connections in Delhi are metered but one-third of

them were no longer working (Ray, 2009). According to Mathur (2001), in Mumbai, 73% of

12

the connections are metered of which 81% of the meters were reported to be non-functional

in 2000.

Currently to avoid the pain of metering and compensate for the unmetered connections a flat

rate is maintained for households. For instance in the Indian city of Gurgaon, Rs. 48/month

($0.8 USD) is charged for an unmetered connection (Saini, 2013). If put into perspective, a 4

member household consuming 18,600 L/month (according to 155 LPCD minimum

consumption) would be paying $0.8 every month (Saini, 2013). Currently even metered

connections are poor as the rates are extremely low. In Gurgaon, households with metered

connections pay Re.1.25/KL (around $0.017/KL) (Saini, 2010) which means consuming

186,00 L/month would cost Rs. 23.25 (around $0.38/month)! For instance if the household

income is $12000/annum (or $1000/month) water price would be 0.038% of the household

income!

Increases in power tariffs, higher costs of labour and material and constantly rising loan

interest rates are crippling the water boards, pushing them towards huge revenue deficits. For

instance, in the case of Bangalore Water Supply and Sewage Board (BWSSB), since the last

revised tariff, expenditures on power has gone up by 46%, the cost of establishment has

increased to 144% and the interest paid by the board on loans has increased by more than

400% (Madhusudhan, 2013). According to the Chairman of BWSSB water tariffs in

Bangalore have not been revised since 2001 (Senthalir, 2011). BWSSB’s deficit in 2008-09

stood at $27 million USD and between 2008-09 and 2011-12 the board lost around $40

million USD as a direct result of not increasing the water tariff (Madhusudhan, 2013).

13

The economic problems facing Indian water boards are not just with the unrevised tariffs. In

a reading being recorded through bulk flow meters in Bangalore, for a monthly supply of

28,888 ML only 15,465 ML was billed meaning the revenue collected is only for 54% of the

supplied water (NUWA, 2012). A similar situation exists in India’s financial capital,

Mumbai. The City’s municipal corporation has realised that currently 360,000 connections

are metered but 100,000 more connections still need to be metered (Baliga, 2012).Hence

higher proportion of unmetered connections and unrevised tariffs pose significant economic

constraints to achieve a better water supply.

2.3. Improper Resource Management

Water scarcity may be experienced if the boards do not execute responsible stewardship of

the available water resources. In high density (population) regions water boards should

endeavor to sustainably tap every single fresh water source. For instance, in Bangalore 300

MLD of groundwater is drawn through private borewells (Nataraj, 2013). Hence the city

does have 300 MLD fresh water source but it is not been put into (equitable) distribution.

Given that India does not regulate water usage, it should come as no surprise that there is

also little regulation on pollution and even less enforcement of what regulations do exist

(Brooks, 2007). A combination of sewage disposal, industrial effluents and chemicals from

farm runoffs, arsenic and fluoride has rendered India’s rivers unfit for drinking (Brooks,

2007). Only half of New Delhi’s 3.66 million cubic meters of sewage is treated and the rest

is released into River Yamuna (Brooks, 2007). The city cannot process the sewage it

produces as 45% of the population is not connected to the sewage system. Those not

connected to sewage lines end up dumping their waste into canals, which empty into a storm

drain that runs into the Yamuna River (Brooks, 2007). Bangalore is in a similar situation too.

14

According to Central Ground Water Board (CGWB) official, the practice of disposing

improper garbage and solid waste into the city’s groundwater source is the main reason for

the pollution (IWR, 2011).

2.4. Summary

Through different cases and examples of Indian cities the chapter highlights various factors

that typically lead to intermittent supply. Absolute scarcity is definitely a key factor that

influences the intermittency. But the fact that even places with abundant source of fresh

water face intermittent supply argues against the myth that such a system is a remedial

measure to overcome water scarcity alone. Hence the chapter stresses on other factors such

as which induce a state of “virtual” scarcity often caused by deteriorating infrastructure and

improper resource management which in turn forces the system to be operated intermittently.

The chapter also attempts to imply that either due to lack of knowledge or negligence,

municipalities seem to look for new sources hundreds of kilometers away but are not

interested to take the initiative required to fix leaky pipes and revenue loss is not caused only

through leaky pipes but also through poor metering and billing policies. The focus of this

thesis is to examine all significant causes and effects of intermittent supply; this Chapter 2

provides a broad platform on which the consequences of intermittent flow can be quantified

and to provide suitable recommendations about such an evaluation.

15

CHAPTER 3

Consequences of Intermittent Water Supply

Once the origin of a problem is established it is necessary to examine and quantify the

consequences of the current situation as a key step toward taking appropriate action. In the

case of intermittent supply, the consequences are all the more important as it is affecting over

a billion people around the world. This chapter highlights the direct and indirect effects of

intermittent supply on the individual consumers, the community as a whole, the distribution

infrastructure and the economy. To aid decision making in the future, the consequences have

been quantified in terms of energy use and capital loss. The chapter has linked various

factors contributing to system deterioration and the phenomena behind the role of supply

intermittency have been well explained.

3.1. Improper Water Distribution and Pressure management

Maintaining a minimum residual pressure is equally important as providing enough water to

consumers to fulfill their diurnal demand. But it is even more important to do this for an

intermittent supply. As the consumers are unsure about getting the next flush in the recent

future they have a tendency to collect as much water as possible in a short duration of time or

till the supply lasts. As the consumption or the quantity collected is directly dependent on the

pressure available at the outlet, consumers closer to the pumping station and low-lying areas

have a great advantage. As there are no guidelines made specifically for intermittent supply,

distribution systems are designed for a continuous supply based on the assumption that the

demand would be spread over 24 hours. In reality, water is drawn in a shorter duration. This

implies that the system capacity can become undersized because flows in pipes are much

greater than anticipated resulting in severe pressure losses. Hence, there is generally a low-

16

pressure regime in the network (Anand, 2002). According to Central Public Health

Environmental Engineering Organization’s Indian Government Guidelines (CPHEEO,

1999), a distribution system should supply a minimum residual pressure of 7 m (of water)

(10 psi) for single storied houses, 12 m (17 psi) for two-storied houses and 17 m (24 psi) for

three storied units. Studies conducted by Nelson (2012) show that the residual pressures at

many points in the city mains ranged between 1.5 Psi to 3 Psi (in the Southern Indian city of

Hubli-Dharwad). According to Environmental Health Project a study conducted in Dehra-

Dun revealed that the available residual pressure at the consumers’ end varied greatly

between seasons (Choe, 1996). As it is a normal practice for households to collect and store

water in clean containers as and when possible, they experienced lower pressures during

summer (dry) season. On average it took 3 minutes to fill a bucket (15 liters) of water during

regular seasons and 7 minutes during the dry season (Choe, 1996). This translates to a drop

in discharge rate from 0.083 l/s during regular seasons to 0.035 l/s during dry seasons.

Considering a basic requirement of 150 lpcd, a household with piped connection would need

to spend 2 hours during regular seasons and over 4 hours during dry season to store water.

Also in Dehra-Dun, just 50% of the residents own a private tap, 30% share the water

connection with their tenants (28%) or with their neighbors (2%) and 18% rely on public taps

(Choe, 1996).

Consumers around the country are upset with the rationing as well as unequal distribution,

especially as the cost of water is almost same for all. Recently the residents New Delhi

protested against the erratic and unequal distribution of water by the Delhi Jal Board (DJB)

across the capital city. The agitating residents strongly believe that the brunt of this unequal

distribution of water is borne by the city’s poor who reside in colonies which are supplied

17

water not through pipelines but through tankers (Kumar, 2012). In the South-Indian city of

Bangalore where water is supplied for duration of 3-4 hours once every three days, similar

problems persist. Consumers who are lucky to have private bore-wells at home enjoy a 24/7

supply while other residents who have limited access to clean drinking water try to manage

with what have stored till the supply resumes. For high-rise apartments or condominium

units the problems vary. Not only do they have to cope with the unequal distribution from

the rest in the city but inequality also exists between the individual units within the building.

The general practice in such high-rise buildings is to store water in overhead tanks form

where it is distributed to the residents. In such a system customers (nodes) at higher

elevations receive water at a lower pressure compared to those at lower elevation, thus

introducing a sense of “water competition” is introduced among consumers.

3.2. Coping Costs

India, today is a fast growing economy with a steady GDP growth rate of 6.3% (ET, 2012).

With increasing per capita income consumers no longer want to settle for a rationed water

supply. Over the years they have started to adopt various measures to overcome the

intermittency but at a cost which is generally called a “Coping Cost”. A considerable coping

cost is incurred to store back-up water during non-supply hours, which is practically the

whole day in many places. Moreover, most rural consumers rely on public water taps, and

thus end up standing in long queues wasting potentially productive time (Global Water

Intelligence, 2009). In Manila those not connected to a 24-hour piped water supply (mostly

the poor) pay around $20 per month for 6 cubic meters of clean water while others with

continuous supply (mostly the rich) pay around $4 per month for 30 cubic meters of clean

water (McIntosh, 2003). The following estimated cost comparison in Figure 3.2.1 shows

18

similar results in India where households with highly unreliable supply (mostly the poor)

incur costs around $27 per month for a mere consumption of 40 lpcd (source of data; The

Hindu, 2012; expressindia, 2009; The Hindu, 2010; TOI, 2011; Chennai Metro Water; EPA,

2004; EPA, 2008)

Fig: 3.2.1 – Cost estimation for various types of supply. The data has been procured for the

estimation from various sources

The estimated “cost” incurred by a consumer in rural areas of India is high compared to an

average consumer, say, in Canada (fig. 3.2.1); these differences are even greater if income

differences are considered. Though water in rural areas is supplied “for free,” consumers

have to travel to tankers and wait in a relatively long queue. With 2 million people in New

Delhi alone and millions others in rural India where 70 percent of the country’s people live

(Fishman, 2011), intermittent supply alone is affecting the economy considerable. In India 32

million households collect water from places over one kilometer away from their homes and

0

5

10

15

20

25

30

Continuous Supply Ground water + Municipal supply

Alt. Source + Municipal Supply

Municipal Supply Supply in Rural areas (India)

Estimated Cost Comparison

Co

st (

USD

)/ca

pit

a/ m

on

th

Type of cost

19

about 170 million people every day who consume water that has been carried home by foot

(Fishman, 2011). The figure depicts what that particular consumer would have earned if

he/she had worked on hourly wages instead of collecting water, an estimate made by

assuming an hour per day is required to collect 15 litres of water. Another coping cost in

developing countries like India is the tapping of subsurface water by consumers through bore

wells to overcome the problems faced due to intermittent supply. Consumers incur costs to

maintain and manage a groundwater supply system within their homes not to mention the

constant worries about the working of submersible pumps when the yield is lower than

expected or when the water quality is not upto drinking standards.

Consumer willingness to pay is crucial, as urban consumers are willing to pay more for better

and reliable service. At Dehra Dun, the total revenue received by the water works department

in 1994 including non-household revenue was approximately Rs.30 million, with the average

pricing of Rs.2/m3. However, studies have shown that with an increase of pricing to Rs.2-

2.5/m3, which consumers were willing to pay for a continuous water supply, the revenue

generated would have been Rs.46 million (Choe, 1996). Hence the water supply issues both

worsen and are worsened by the financial problems. Raghupati and Foster (2002) found that

on average in India a five member family with a per capita monthly budget of Rs.350 would

pay up to Rs.6 per KL (Kiloliter, or cubic meter) for a block up to 10 KL per month. Given

that estimates of operation and maintenance costs in the range of Rs.15 per KL, subsidies are

thus provided by the water board. It is estimated that the federal government of India spends

US$1.1 billion (0.5% of India’s GDP) to subsidize the water supply, but 70-80% of this does

not reach the poor (Ray, 2009).

20

3.3. Overexploitation of Ground Water

Groundwater supplies 80 percent of water for domestic use in rural areas and almost 50

percent of water for urban and industrial uses (DFID, 2005). Presently as there are few

government regulations in India for domestic groundwater usage which has resulted in

widespread overexploitation of groundwater resources. Industries further contribute to the

overexploitation. For instance a Coca-Cola plant in Kerala (an Indian province) faced a

lawsuit and eventual closure in March 2004, as it was drawing so much subsurface water that

the groundwater table was being depleted (The Hindu, Business Line, 2004).

Overexploitation of groundwater, especially in Bangalore and groundwater contamination

are posing serious health risks. There are around 312,000 borewells in Bangalore from where

300 MLD of water is drawn for domestic use. The withdrawal rate is 3.7 times the rate of

recharge which is the reason why the borewells have gone to depths of 1000 ft (300 m) and

beyond (Nataraj, 2013). Once the households install borewells, they are free to draw as much

water as desired as their consumption is not metered. Only cost they would incur for

consuming groundwater is mainly for power and general maintenance. With the current

domestic rates of Rs. 36/KL and 300 MLD of unmetered groundwater consumption, the

municipality is falling short of an annual revenue of $71 M (assuming $1USD = Rs. 55).

Hence household with access to groundwater consume over 300 LPCD whereas large

sections of the community live on less than 100 LPCD. Reportedly many borewells in the

city are already going dry, meaning the residents have to dig deeper as the groundwater

levels are depleting (Deepthi, 2013). Rapid urban development has added to the woes. With

built-up area in Bangalore amounting to nearly 560 sq. km., just 240 sq. km. of open spaces

are available for groundwater recharge (Deepthi, 2013). This explains why, though the City

21

receives a rainfall of 830 mm just a miniscule 2% seeps into the ground (Deepthi, 2013).

With the current consumption rates it is feared that the groundwater source may be exhausted

by 2018 (Sudhir, 2013) which will leave over a million residents without sufficient potable

water. Unprecedented increase in the number of borewells has lead to other major concerns

in Bangalore. Geologists have warned against the increase in number of bore wells, which is

claimed to be a major cause of earthquakes (NIDM, 2007). Apart from the existing

uncontrolled consumption and disparity in resource allocation concerns are raising over the

quality of groundwater, which is further discussed Chapter 3.7.3.

3.4. Unhealthy Practices and Water Losses

Due to the uncertain timing of water delivery in an intermittent supply, people tend to collect

as much water as they can in the supply duration, but often dump the stored water when they

get their next newer and “fresher” installment. Water hoarding is a common practice in every

Indian home, be it in the form of tanks or a series of smaller containers. Consumers do not

actually keep track of the amount of water collected as their only aim is to collect as much as

possible in the supply hours. The main purpose of an intermittent supply is to reduce

consumption and leakage, but this practice can cause people to consume and waste more

water than they normally would in a 24-hour supply.

Studies have shown that real leakage represents 25-40% of water produced by utilities in

urban areas of India (Ray, 2009). In Zambia, on average 50% of the water produced by the

commercial utilities were unaccounted-for in 2006, providing revenue for only half the water

produced (Hulya, 2008). Leakages can happen due to extreme surge in pressures or too much

variation in temperature, from which cracks are caused (South African Government Online,

Draft-15, 2000), particularly in deteriorated lines.

22

3.5. Constraints to meet fire flow needs with the present system

Major constraints are experienced while meeting fire flow needs during intermittent supply.

According to Bureau of Indian Standards (1990), for every 50,000 population, water for

firefighting needs should be provided at a scale of 1800 L/min up to a population of 300,000

and for every 100,000 hence, an addition 1800 L/min should be provided for a duration of 2

hours. This would mean for instance in the major cities with a population of over 5,000,000,

95,400 L/min of supply must be available for a period of 2 hours or 11 million L per day.

With the supply duration ranging from a several minutes to few hours a day, the supply

would be able to meet fire flow needs only if the fires occur in specific regions during the

supply duration. Further, with a great disparity in residual pressures at the consumers’ end,

the probability of fighting fires is further reduced during intermittent supply. In the year

2005-06 the total fire losses paid by just four insurance companies in India was over USD $2

billion ( ). The accidental death statistics provided by National Crime Research

Bureau, India reveals that about 19000 people per year lost their lives due to fire during the

years 2003 & 2004 ( ).

3.6. Increasing Costs and Rising Energy requirements

3.6.1. Pressure losses and corrosion processes

Water distribution systems need continuous pumping to lift water from the source to an

adequate elevation to provide the required residual pressure at the consumers’ end but pumps

also need to overcome the frictional losses in the system. The lift requirement alone is termed

as static head and the lift with the frictional losses together is termed as the dynamic head

which should be supplied by the pump. The basic idea of static and dynamic head and higher

energy required to pump water through a corroding pipe is illustrated in the simple single

pipe system below (Figure 3.6.1).

23

Fig. 3.6.1: Conveyance energy requirement in pipes with different corrosion levels

In Fig. 3.6.1 (similar to the one depicted in Filion et. al. (2004)) an arbitrary datum of zero is

chosen to coincide with the centerline of the pipe. The pump that is assumed to be located at

the upstream end of the pipe (left hand side) is supposed to lift water to the stated static head

( downstream of the pipe by overcoming the frictional head-loss along the pipe. The total

energy needed is hence equal to the sum of static head and frictional head-loss along the

pipe. This study is aimed at estimating the net energy difference (benefit) on migration from

intermittent to 24-hour system by calculating the energy spent in overcoming the frictional

head-loss is pipe system.

Attack on the pipe material leads to thinning of the pipe walls or formation of precipitate.

Corrosion of metals, in general can be of different forms: a) an overall surface attack slowly

reduces the thickness, b) a localized area may be affected, or c) along the grain boundaries or

other areas which offer less resistance to the corrosive action (Charng, 1982). Apart from

causing a change in the water quality, thinning of pipe walls might increase the probability of

a catastrophic failure and formation of a precipitate will decrease the hydraulic capacity, due

to increase in friction and hence increase the pumping cost. Corrosion of water distribution

pipes happen in continuous as well as intermittent supply systems. The present study

Static head

Q

Static head

, Continuous Supply

, Intermittent Supply

Total Head

required (IS

system)

Total Head

required (CS

system)

Net Energy

Saved due to

migration

24

compares the rate of corrosion and its effects on the total energy embodied in water

transmission.

Corrosion occurs due to the electrochemical processes that take place on the metal surface of

the pipes. and is caused by an anodic area and a cathodic area occurring simultaneously on

specific points on the metal surface. Anodic and cathodic areas are formed by factors such as

non-homogenous metal composition, differential surface conditions, metal stresses or

variation in solution concentration.

It can also be caused by differential aeration cells, which are concentration cells resulting

from the differences in oxygen concentration between two parts of the system. During an

intermittent supply, where the system is not pressurised most of the time (on an average the

system is pressurised for 1.5-4 hours/day), water is left to stagnate in the pipe creating a

condition within the system where water and air are simultaneously in contact with the

metallic surface of the pipe (more like in an open channel flow at the air-water interface).

This results in a difference in potential between the portion of high oxygen concentration and

that of low oxygen concentration. states that the principle cause of corrosion in

water is the oxygen concentration cell and this crucial mechanism has not been given the

attention it deserves in most publications on corrosion, perhaps because it introduces an

apparent anomaly: Oxidation of metal occurs at a site where there is no oxygen. The

following Fig 3.6.2 ( ) depicts the series of electrochemical reactions that occur

during the corrosion process.

25

Fig. 3.6.2: Corrosion occurring at the water-air interface

Corrosion occurs in differential aeration cells at the area of low oxygen concentration.

During an intermittent supply, it occurs at the water-air interface which can be attributed to

differential aeration. Oxygen from the air is available to the meniscus area formed at the

water line. As oxygen is depleted at levels beneath the water line, the meniscus area becomes

cathodic to the immersed iron. illustrates the electrochemical processes involved

in the corrosive action caused when air and water are simultaneously in contact with the

metal surface, which is the pipe wall in the case considered here. Figure 3.6.2 depicts an

oxygen concentration cell where the chemical reactions involved are precisely the same as

those that occur in a galvanic cell. Since voltage produced by the cell is determined by the

chemical reactions, the potential of any oxygen concentration cell will be exactly the same as

in a galvanic cell where the corroding metal is the anode.

The oxygen concentration cell may be initiated by anything that will shield a small area from

the dissolved oxygen in the water, such as a grain of sand or a microbial colony. Such agents

which are responsible to initiate the process are known to be in abundance throughout the

water distribution systems in countries where intermittent supply exists. In hard waters, the

Tubercule: outer shell is rust (ferrous oxide) and inner shell is

black ferric oxide. Interior is void of oxygen.

26

alkaline cathodic reaction products precipitate calcium and magnesium compounds, which

deposit on the iron and shield a part of it from the aerated solution ( ). Since this

shielded area is deprived of oxygen, corrosion occurs here at the water line. Study conducted

by Koliyar and Rokade (2007) in Mumbai (Powai lake) showed the water hardness level to

range between 128-166 ppm and hence could be classified as Hard (with Soft ranging

between 0-60 ppm and very Hard having a concentration > 180 ppm). Once started, the cell

becomes self-perpetuating. The effects of the cathodic and anodic areas on galvanic

corrosion are very important. As the ratio of cathode to anode area increases the current

density at the anode increases making depolarization at the cathode more effective. Thus a

large cathode area and a small anode area would accelerate the corrosion process. According

to Charng and Lansing (1982), in such cases, corrosion of the anode may be 100 to 100 times

more than if the areas were the same.

Corrosive action due to the varying fluid velocities in conduit system is another important

factor that specifically affects pipes in an intermittent supply system, but has not been

touched upon in the past. Charng (1982) briefly describes how fluid velocity in the conduit

system affects the rate of corrosion. An increase in relative velocity between a corrosive

liquid and a metallic surface tends to increase the corrosion rate. This occurs due to the

increase in rate at which different corrosive substances are brought to the surface by the

moving water. Metallic corrosion is resisted by the layers of insoluble corrosion products that

settle on the surface. Higher velocities either prevent the normal formation of the corrosion

products or may remove them after (or as) they are formed. Hence thinner will be the films

through which corroding substances must penetrate and through which soluble corrosion

products must diffuse. In either of the cases the corrosion process would proceed unhindered.

27

Typically in an intermittent supply water would stagnate in the pipe for hours (from a few

hours to a few days) assisting the process of corrosion to take place at the water-air interface.

When the next flush of water is pumped or when supply resumes, high velocity of water in

the pipe and/or the accelerating fluid mass removes the corroding layers making way for

further corrosion to occur. Corrosion rate influenced by fluid velocity occurs frequently in

small-diameter pipes at high velocities (Charng, 1982). Velocity effects on corrosion rate

could be divided into various ranges depending on the velocity magnitude (Charng, 1982):

a) Slight motion (less than 0.3 m/s) may stop localizing attack such as pitting corrosion;

b) At around 0.3 m/s, the flow rate may increase the oxygen supply to a level that will

increase the rate of corrosion to as much as 1 mm/year;

c) At velocity range between 2.4 to 3 m/s the corrosion rate will be around 0.3 to 0.8

mm/year, depending on the surface roughness;

d) At velocities over 4.5 m/s, turbulence could accelerate the corrosion rate upto 5

mm/year.

Currently available literature does not address the effect of repeated line filling where the

accelerating liquid mass removes the corroding layers making way for further corrosion as

mentioned earlier.

3.6.2. Water Distribution System deterioration - Pipe Breaks

Distribution networks often account for up to 80% of total expenditures involved in water

supply systems. As water mains deteriorate both structurally and functionally, their breakage

rates increase, network hydraulic capacity decreases, and the water quality in the distribution

system may decline (Kleiner and Rajani, 2002). Also, 55% percent of the cause for breaks

can be attributed to material deterioration (Kirmeyer et al., 1994). It is essential for water

28

utilities to have short term operational plans to meet the consumer demand and have long

term infrastructure plans as distribution networks involve huge capital expenditures.

An important parameter that defines the reliability of a distribution system is its

susceptibility to breaks and bursts. Flooded streets due to water main bursts causing

inconvenience and heavy loss of resources are a common sight in India. Many factors

contribute to the rate of pipe breaks; material defects induced during water distribution,

ageing, corrosion from soil, water hammer or pressure surge and accidental or damage

caused due to unauthorized consumption. Though reasons are many, according to Shamir and

Howard (1979) the primary cause for the occurrence of breaks can be classified into

following categories:

1. Ageing of pipe and other appurtenances as well, which would include corrosion;

2. Type of environment in which the pipe is laid;

3. Quality of maintaining workmanship; and

4. Water supply conditions such as transient pressure conditions and water hammer.

Breaks occur in continuous as well as intermittent supply systems but extra care should be

taken in reducing the number of breaks when the supply is intermittent as further losses in

resources or additional financial burden would lead to further rationing. Agbenowosi (2000)

states that the cost of rehabilitation is the United States alone is estimated at more than 23

billion dollars. Also as intermittent supply systems are not sufficiently pressurised breaks do

not show up on the surface (Charalambous, 2012).

One of the common conditions that strongly influence pipe breaks is water hammer. Liquid

(water in this case) flowing in a pipe has two types of energy, a) potential energy and b)

29

kinetic energy. At any point in the system the sum of potential and kinetic energy is a

constant. Hence decreasing the flow rate (decreasing the kinetic energy) within the pipe

would result in an increase in the fluid pressure within the pipe as a result of increasing

potential energy. The immediate surge in pressure that generally occurs during rapid valve

closure, pump starts/shutdown, water-column separation and air movement in pipes is termed

as water hammer (or pressure transient). Water hammer is hence a pressure shock wave

induced in a plumbing system due to any rapid local adjustment of flow or pressure. The

instantaneous pressure shock wave of 150 psi or higher, tends to dissipate through the

system. Pipes, pipe joints, valves and other appliances absorb these shock waves, sometimes

causing a loud hammering sound and vigorous high amplitude vibrations. As a result of

continuous chemical attack as described earlier the pipes lose their bearing capacity and

become susceptible to physical damage. Due to the continuous line filling and valve

operations in an intermittent system pipes and other appurtenances are constantly subjected

to high intensity shocks leading to cracks, breaks and bursts more frequently. More details on

the occurrence and consequences of pressure transients are presented in Chapter 3.7.

3.6.3. Air Entrainment

Entrained air in water and wastewater networks has a deleterious effect on the system as a

whole the infrastructure environment and users. Air enters systems when it comes into

contact with flowing water and there is a favourable pressure gradient. Air entrainment may

occur in pumps due to turbulence at the inlet in dropshafts where water is transferred from

higher to lower elevations in open flow or at check towers if flow is partially full. Dissolved

air can also be released if temperatures increase or pressure drops occur; for example,

changes in pipe elevation or partially open valves, variations in pipe diameter can all cause

30

pressure changes. A 100 m length of watermain could contain 4 kg of total combined air.

This is truly a noticeable and significant amount (Lauchlan et al. 2005).

Entrapped air can reduce energy efficiency in pipelines by as much as 30%; it disrupts flow

in addition to increasing head-loss pressures energy consumption (Thomas, 2003) and

consequent greenhouse gas emissions (Maas, 2009). Higher pressures cause greater leakage

in the system, increases the chances of contamination and result in more frequent bursts as

well. The presence of air specifically oxygen in the pipes also increases the potential for

corrosion.

Pipelines are repeatedly filled and emptied in an intermittent supply, which causes the inflow

of air through faulty taps and open faucets. During an intermittent supply faucets are always

kept open as there is uncertainty about supply hours. The inlet of air resists the flow of water,

and hence the initial head needs to be increased to maintain the flow of water, which is again

a waste of energy. During rapid line filling, these air pockets can exert substantial pressure

on pipe walls, joints and valves. For example, Holley’s (1969) experiments and field work

suggest that storage and release of entrapped air can of initiate severe surges in pipelines.

During pump shutdowns, characteristic of intermittent supply, Albertson and Andrews

(1971) found that the maximum peak pressure could be 15 times the operational pressure. As

these high pressure conditions occur repeatedly during intermittent supply, regular but rapid

line filling is likely to lead to high rates of ruptures, bursts, leakages and other operational

problems. Hence it is no surprise intermittent systems usually have such high leakage rates.

31

3.7. Water Contamination

Contamination of drinking water being one of the most central problems in developing

countries, it is necessary to evaluate and understand how intermittent supply systems create a

favorable environment to facilitate the process of contamination.

3.7.1. Water Contamination during Pressure Transients

Contaminated water has become a serious cause for the outbreak of many diseases, and often

occurs due to frequent supply interruptions. This section describes how factors such as the

occurrence of pressure transients (water hammer) and water stagnation induces

contamination of conveyed water and more importantly why the effects are more pronounced

in an IS system.

The basic equation for the pressure transient, traditionally called the Joukowski Equation,

relates the change in pressure to change in fluid velocity (Tijselling and Anderson, 2006)

according to:

(3.7.1)

where is the sudden change in pressure, is the sudden change in velocity, is the

density of water (or fluid), is the speed of sound. Korteweg’s (1878) formula defines c for

liquids in cylindrical pipes with circular cross section as:

(3.7.2)

(3.7.3)

where D is the diameter of the pipe, e is the pipe’s wall thickness, E is the Young’s modulus

for the pipe wall and K is the Bulk modulus water (contained liquid). The magnitude of

32

pressure change is hence influenced by factors like pipe material, characteristics of the liquid

being conveyed and any rapid variation in fluid motion. Of these the primary cause of

concern is any operational change such as valve closure, pump shut down, fire-flows or even

pipe breaks that could potentially lead to rapid change in flow velocity. For instance if a

valve, considered on a pipeline at a distance downstream from a reservoir is closed

instantaneously, the water in the pipeline will decelerate to zero velocity thereby converting

the kinetic energy (possessed by the flowing water) into potential energy (pressure). The

pressure wave hence travels through the pipeline (i.e., upstream and downstream from the

valve) and if not absorbed by a surge tank, it will travel in the reverse direction back to the

valve (LeChevallier et al., 2003). As the valve is closed and there is no relief for the flow, a

negative pressure wave is created at the valve (Simon and Korom, 1997). This wave travels

back and forth until the energy is dissipated by friction (LeChevallier et al., 2003). However

the initial pressure would be positive on the upstream end and negative on the downstream

end (Simon and Korom, 1997). Pressure transients can also be caused by main breaks,

sudden changes in demand, uncontrolled pump starting and stopping, air valve slam and

other conditions (LeChevallier et al., 2003). Though circumstances that introduce transient

condition may commonly occur in any distribution system, certain conditions occur more

frequently in an IS system. LeChevallier et al. (2003) reports that as a rule of thumb, for

every 1 ft/sec (0.305 m/sec) velocity being forced to stop, water pressures increase 50 to 60

psi. The opposite would be true if there is a sudden velocity increase, resulting in an

instantaneous low or negative pressures (LeChevallier et al., 2003). Sudden increases

(changes) in demand with high peaking factor occur frequently when the supply is

intermittent as the consumers in a rush to collect water might not restrain filling or might

33

even use booster pumps. Andey and Kelkar (2007) study the systems in four different cities

in India that were operated continuously and intermittently at different times and report the

demand patterns.

Peak factor

IWS

Ghaziabad Jaipur Nagpur Panaji

6.15 4.38 2 6.4

CWS

3.06 1.66 2.02 1.98

Table 3.7.1

As reported in Table 3.7.1 (Andey and Kelkar, 2007) the peak factor in an IS system is can

be 2 to 3 times the peak factor in a CS system. Peak factor can be defined as ratio of the peak

diurnal demand during a 12 month period to the average day demand over the same period.

But Bose et al. (2012) report a peak factor to range from 3 to 12 due to IS in India. Transitory

contamination can occur when a negative or low pressure in the distribution system allows

untreated water to backflow into a distribution main through leakage points, submerged air

valves, cross connections, faulty seals or joints (Kirmeyer et al., 2001). Kirmeyer et al.

(2001) weighs and ranks the pathogen entry routes into the distribution system. Routes of

entry such a transitory contamination and water main breaks are termed as high risk. With IS

systems experiencing higher rates of water main breaks, this is certainly an additional cause

of concern.

To arrest the shock waves developed during transient regimes, surge tanks, air chambers or

other water hammer arresters are often used, but such strategies are costly. However, if the

arrestors are not completely water tight, the entrance of water hinders the cushioning effect.

To release the trapped water, the whole pipe system has to be drained (by opening the lowest

34

faucets first and then the other faucets) keeping the mains closed. Once the pipe system is

drained, the water present in the water-hammer-arresters is also expelled. The main valve

should now be opened allowing a fresh flush of water to fill the pipe system. This is just a

temporary solution and water hammer can still continue after a while as soon as water starts

entering the arresters. Considerable water is wasted in reducing the effect of water hammer,

and most water hammer mitigation techniques are not well-suited to intermittent flow

systems.

Further, tank agitation and disturbance of impurities are other serious problems induced by

water hammer. During water hammer the shock waves are transmitted up to the storage

tanks. These waves agitate both pipes and tanks and thus disturb the settled impurities,

bringing them back into suspension. This is observed to be causing key water quality issues

in the South-Indian city of Mangalore. As a result, even though treated water might be

delivered, it does not always reach the customers in a potable form.

Contamination due to intrusions could result in unnerving consequences people’s health. A

public relations officer in the Ministry of Defence reported that during a recruitment process

even 50% of the position could not be filled as the candidates failed in their medical tests due

to defects in their bone structure (Vajpai, 2012). Further investigation revealed that these

candidates came from arsenic affected regions in the Indian province of Bengal (Vajpai,

2012). Arsenic can affect any organ including bones causing deformity, degeneration and

brittleness (Vajpai, 2012). Increases in number of leaky pipes and more frequent pressure

transient conditions could induce the more polluted groundwater to enter into the pipes. The

problem is especially aggravated when supply pipes are close to sewage drains. According to

TOI (2012) a recent inspection by the concerned authorities in Bangalore (India) revealed

35

that sanitary and water pipes run next to one another and at some places the water pipes were

submerged in sewage. This is practiced as it is convenient to lay both the pipes (water supply

and sewage pipes) in the same trench (Fishman, 2011).

3.7.2. Water Stagnation in Pipes and Tanks

Contamination due to water stagnation occurs over two distinct stages (or sometimes three)

during intermittent supply. The first stage is in the distribution pipes where water is

invariably left to stagnate for long periods, inducing leaching, scaling, and corrosion, which

results in contamination. Copper is the most common material used in plumbing appliances,

and copper itself is capable of creating a health hazard if contamination is extensive. The

United States Environmental Protection Agency (USEPA) has found that even short periods

of exposure to copper can cause gastrointestinal disturbances, including nausea and

vomiting. According to the EPA, persistent (multi-year) consumption of drinking water

containing over 1.3 milligrams per liter of copper can cause liver or kidney damage (Water

Quality Association, 2005). Copper content in water is also responsible for corrosion and

deterioration of aluminium utensils and galvanised steel fittings. Fabbricino (2005) shows a

direct proportionality between copper concentration in stagnating water and stagnation length

for short periods, though not surprisingly for longer periods (greater than 48hrs) the trend

reaches a plateau.

The second stage of contamination occurs at the storage tank (underground or overhead). A

third stage of contamination is also possible if underground and overhead tanks are used

simultaneously. Lautenschlager et al. (2012) analyse the effect of overnight stagnation of

drinking water household taps. Though the study is confined to the stagnation in household

36

taps the cell concentrations reported to have increased 2 to 3 folds after the stagnation.

Microbial regrowth and its effects have been analysed by various studies and reports. There

are concerns in the drinking water industry regarding the health effects of HPC

(Heterotrophic Plate Count) bacteria that are found in sources of potable water (Rusin et. al.,

1997). HPC in drinking water should not exceed 500 CFU/mL because of the interference of

coliform detection. Higher numbers (HPC) in distribution system are often the result of

bacterial regrowth (Rusin et. Al., 1997). Microbial regrowth could play a vital role in

transferring antibiotic resistance factors to pathogenic bacteria and might also invalidate the

existing water quality monitoring programs (Evison and Sunna, 2001). In a joint research

Project aimed at studying the effects of microbial regrowth in distribution systems, increases

in HPC levels of up to five orders magnitude were reported in a 7-day period when the

supply was intermittent (Evison et. al., 2001).

In India, 85% of the people receive access to drinking water, but barely 20% receive access

to drinking water that meets health standards (Vairavamoorthy, 2007). Intermittent supplies

were responsible for the paratyphoid fever that broke out in New Delhi in 1996

(Vairavamoorthy, 2007). It is estimated that India loses at least 90 million days a year and

around Rs.6 billion in production losses and treatment (Ray, 2009). In Pakistan, because of

pollutants infiltrating into the leaky, damaged, non-pressurised pipes, many water-borne

epidemics swept the regions of Faisalabad, Karachi, Lahore, and Peshawar during the first

half of 2006 (AWDO, 2007). In Karachi (where half the 10 million population live in

informal slum areas) and Lahore (population 5 million), 40% of the water supply is

unfiltered and 60% of effluent is untreated (AWDO, 2007).

37

3.7.3. Privatization and Groundwater Contamination

Groundwater contamination is a serious problem particularly so in regions where consumers

are relying totally on groundwater for their needs. Arsenic contamination in North-Eastern

parts of India and Bangladesh and its consequences to the human health has been reported as

one of the world’s biggest natural groundwater calamities to the humankind (Ghosh and

Singh, 2009). Consumers essentially rely on handpumps and public borewells for water as

the municipal supply is either intermittent or just ceases to exist. These regions where the

supply is rationed are the same regions that have access to perennial fresh water sources.

According to data reported at the Indian Parliament in 2012, groundwater in 158 out of 639

districts has gone saline, in 267 districts groundwater in pockets were found to contain

excess fluoride, in 385 districts nitrate concentration was found to be over the permissible

levels, similarly 53 had excess arsenic levels and 270 with high levels of iron (Sethi, 2012).

It is almost inevitable that absence of reliable continuous water supply will tend to force

consumers to rely more heavily on the contaminated groundwater. It can also be expected

that in most cases they will be oblivious to the repercussions of water supply contamination.

Around 65 million people in India alone suffer from fluorosis which is a sometimes crippling

disease that occurs due to high levels of fluoride in drinking water and five million are suffer

from arsenicosis in the eastern province of West Bengal alone (Gupta, 2013). A UN report

says that over three million people die of water borne diseases in the world and in India alone

over 100,000 die annually (Gupta, 2013). Over 20% (around 300 MLD) of Bangalore’s water

demand is met through private borewells. Laboratory tests reveal that 53% of the borewell

water in Bangalore is not in potable form and contain Escherichia coli (E coli) bacteria

(Nataraj, 2013). The Center of Science and Environment reports another disturbing fact. Due

38

to the lack of sewage treatment and disposal facilities in the City, as many as 600 lakes in

Bangalore urban area have been turned into sewage tanks which contaminates the ground

water and percolates into the borewells (Nataraj, 2013). Another report by the Geological

society of India outlines some hard facts about Bangalore’s groundwater. Samples of

groundwater suggested that fluoride contamination is up to 5.3 mg/L as against a permissible

level of 1.2 mg/L (Madhusudhan, 2013). Nitrate (which affects blood cells) concentrations

range from 16-554 mg/L compared to a permissible level of 50 mg/L and chromium

contamination touched 17 mg/L when the permissible levels were as low as 0.05 mg/L

(Madhusudhan, 2013).

3.8. Summary

This chapter quantifies the consequences of intermittent systems. Through an extensive

literature review the current situation in developing countries with respect to water

distribution has been extensively discussed. Costs incurred by consumers in developed

countries for water consumption and coping costs incurred by different sets of consumers

facing intermittent supply have been compared. The reasons behind the increasing costs and

rising energy requirement to maintain intermittent systems have been examined. Various

forms of water contamination have been presented by highlighting the influence of

intermittent systems on water quality. To cope with intermittency consumers are often forced

to exploit groundwater which is disadvantageous in many ways as discussed in this chapter.

Efforts were made through Chapter 3 to present the deleterious effects of intermittent

systems and thus the need for migration towards a 24 hour supply has been justified. In the

following Chapter possible solutions for converting intermittent supplies into continuous

supply systems will be presented.

39

CHAPTER 4

Recommendations and Analysis of the possible solutions

Having argued that intermittent supply is neither a cost effective nor energy efficient way to

cope with water scarcity, it is important to find an alternative(s) that not only meets

consumer demands but in all possibility is sustainable.

The origin and causes of intermittency have been discussed in Chapter 2. Further on the same

lines, Totsuka et al. (2004) categorise the origin of the problems which would aid in our

attempts to arrive at relevant strategies. The three main categories of water scarcity according

to Totsuka et. al. (2004) are as follows:

a) Scarcity from poor management (Type 1): This could also be termed as perceived

scarcity. Even though the available water sources are sufficient to meet the consumer

demand, the supply must be rationed due to mismanagement of resources, excessive

wastage due to leakage, uncertainty in power supply or even complete negligence

from the respective municipal and Government authorities.

b) Economic scarcity (Type 2): Rapid urbanisation and population explosion in urban

areas could be the main cause of such a scarcity. When such a population increase is

not forecasted, poor planning in the past can lead to limited hydraulic capacity of the

system. In many cases Type 2 and Type 1 occur at the same time or as it is expected

Type 2 could lead to Type 1 in which case too it might seem that they occur

simultaneously. Generally it is hard to clearly categorise a particular situation as

purely Type 1 or Type 2. Bangalore well exemplifies this category, as rapid

industrialization during and after “Dot-com bubble”, saw 1000s of Information

Technology and Bio-technology companies being set up in the city. As planners were

40

not aware of the future demands and were taken by surprise as the City became a hub

for technology-based companies. The same trend could be observed in other cities

too. Though Mumbai is also facing rapid urbanisation, it was expected to become

India’s financial capital since Independence, hence could be categorised as Type 1.

c) Absolute Scarcity: This is the most difficult problem to solve as linking sources

located farther apart might not be realistic but again the issue might be at least partly

economic. However solutions have sometimes been found within water stressed

countries itself. Though consumers also need to cooperate and share responsibilities

in such cases Totsuka et. al. (2004).

4.1. Immediate steps to move towards a continuous Supply

Several immediate steps can be taken to help move a system away from being intermittent;

these are summarized here, with the most promising being to reduce the need of water

through an active and aggressive water conservation program.

4.1.1. Water Conservation

As analysed in Chapter 2, the issues forcing the municipalities to supply water intermittently

need to be dealt in isolation as every case presents a new problem. Water conservation

strategies are proposed through a framework developed for specific cases taking into account

demographic and socio-economic factors. While water demand management techniques

consider all aspects relating to efficient use, water conservation to minimize water loss is

confined water resource efficiency.

The following solutions and strategies are aimed at controlling the demand and reducing

wastage.

41

4.1.2. Water Demand Management

Water demand management (WDM) is the implementation of strategies to more efficiently

use water by curtailing unnecessary consumption particularly if those reductions can be

achieved without reducing the quality of life; the goal of demand management is to foster

social development, social equity and sustained water supply. WDM has not been fully

recognized in developing countries, as it is considered an objective but not a strategy (South

African Government Online, Draft-15, 2000).

Underground and Overhead Private Tanks: Continuous supply is only possible if the utility

has sufficient water to supply the demand throughout the day. If consumers, as they always

practice when the supply is rationed, collect as much water as they can, water utilities can be

under extreme stress to cope with such a peak factor. Hence as a first step consumers should

strictly stop using private tanks or booster pumps. However as it is impossible to prevent

consumers from hoarding excess water through other means their daily consumption must be

indirectly controlled. There are three ways to implement such a practice:

1) Stringent Billing Process: This method employs installing smart electronic water

meters at individual residential units which keeps a record of daily usage as well as

the monthly usage. The smart meters being considered here are capable are

communicating with the servers managing and processing the datasets. Such meters

that are available today (e.g., Sensus, FlexNet) are capable of sending data on an

hourly basis. On a per-capita consumption basis, 155LPCD (CPHEEO, 1999)

household consumption should be billed normal rates. In cases where the daily

consumption exceeds the stipulated 155 LPCD, the amount exceeding the limit

42

should be billed at exorbitant rates. These rates must be fixed based on the price of

commercially available drinking water. This would ensure the consumers will have

enough water for their daily needs but the onus would be on them to make sure they

do not waste or collect more than what is required.

2) Fix a daily quota for water usage: Fixing a daily quote can be an effective strategy if

every household is allowed to collect a set volume of water every day. After the

diurnal limit is reached the Flow Management Device will stop the supply for the

particular residential units for the day. Also, depending on the water affordability,

consumers can choose their daily quota and hence plan their consumption.

This new water management practice is already in place in Cape Town (South

Africa). The device is set to deliver an average of 350 L/day or 10.62 L/month

( ). If households use anything less than their daily quota, the remaining

amount will be carried over to the next day.

As the price of water is very low in India (e.g., 10 cents/1000 L in Bangalore) middle

class and upper middle class households tend to use much more than the required

amount. For instance middle and upper middle class households in Bangalore often

use 250 to 300 LPCD. Again, a middle-class consumer in Mumbai consumes the

same amount of water as his/her counterpart in Shanghai (Varghese, HT) while the

supply in Mumbai is still intermittent. Hence if such strict measures are brought into

place i.e., with a strict consumption 155 LPCD, water demand (for its 12 Million

citizens) in Mumbai alone can be brought down to 2139 MLD (which includes 15%

loss due to leakage).

43

4.2. Pressure Management and Leakage Control:

Though a complete system overhaul is needed in regions with ageing pipes, it is an expensive

and time-consuming process especially in the developing countries where ample data on pipe

locations may not be readily available. Also, a slow process is preferred as initially it is

required for consumer behaviour to adapt to continuous supply. Even if it takes a few years

to replace all the ageing pipes and completely migrate towards a 24/7 supply, water and

energy conservation strategies should be implemented immediately. Only if the

municipalities have enough resources is a system overhaul or a migration feasible. With IS

systems experiencing leakages ranging from 30% to 50% of the supplied water, leakage

reduction is an important and cost effective way to improve the supply conditions as minimal

additional infrastructure is required. Since high pressures increase leakage, pressure

management through leakage reduction is crucial.

Pressure management: Some developing countries face a serious water scarcity problem.

In such cases, an immediate migration to a 24-hour supply would seem to require completely

new water sources. If this is infeasible, the migration should occur in phases where the water

boards can plan and implement demand management and leakage reduction strategies. Hence

the best water boards can do in these cases is to improve supply conditions initially so that

the consumers stop hoarding water. The basic idea here is to reduce the peak demand and

diurnal demand to assist water boards to have enough water to supply demand over a longer

duration. In other words water should be supplied to consumers more frequently at a constant

pressure. For instance if presently the daytime supply period is for 2 hours, it could be

improved by re-distributing the supply period between two separate durations of 1 hour each

44

during different peak hours. In such an improvised supply system, consumers would collect

only the required volume of water as they are confident of promptly receiving the next flush.

Hence this would solve the problem of wastage which otherwise would be prevalent as

consumers tend to discard the stored water when they get the next flush.

South Africa was one of the first countries to implement pressure management on a large

scale, and the results of their efforts were fruitful. Pressure management was undertaken in

Cape Town and results were reported for the township of Khayelitsha. Water was supplied to

around 27,000 small housing units, a population of 45,000. At the beginning of 2000, water

supplied to this town was measured to be 22 million m3/a (McKenzie, 2009). Leakage from

night time water usage was three quarters of what was supplied, due to excessive night-time

pressures where water was supplied at a rate of 1600 m3/hr (McKenzie, 2009). The main

source of this leakage was identified as household plumbing and fittings which were

constantly exposed to high pressure of around 80 m. These leakages result in high

consumption and people would not try to replace expensive taps and fittings.

An excellent way to reduce the leakage level is to divide the network it into permanent

sectors which are supplied by a single pipe on which a flow meter is installed. In this way it

is possible to easily detect a new leak and know from which part of the network it comes

(Rogers, 2008). The application of a mathematical model that simulated key hydraulic

features would solve the problem of numerous interconnections and inaccessibility to various

elements of the network. For a good mathematical model to be developed, relatively perfect

datasets and appropriate estimation techniques are needed to assess the consumption pattern.

Thus for the simulation to be precise, historical consumption of the customers could be

extracted from the billing database by street and type of customer. As performed by DEWI

45

Srl in Lucca (Italy), an extensive monitoring program could be undertaken in similar cities

(i.e., cities with similar characteristics) to derive a demand profile for customer types. By

successfully simulating the network operation it is also possible to find and close the pipes

with little hydraulic importance without causing serious service problems to its consumers

(Rogers, 2008). Analyses of the results show that the application of these strategies yielded a

leakage recovery of 72 L/s or 2.2 Million /s in Lucca(Rogers, 2008).

4.3. Improved Metering and Billing Procedures

Maintaining a system where all the connections are metered is important not only because of

improved revenues but also for generating consumption data for future planning and leakage

detection. Observations and surveys on installed meters will allow for a better estimate of

non-revenue-water and would help determine the investment needed to replace these meters,

while research on them would help to determine reasons for their faulty behaviour. Also

consumers should be discouraged from tampering with a metering system, with stiff

punishments for violation.

Appropriately revised rates and Billing in Stages

General water rates must be revised to recover the operation and maintenance costs of the

water distribution system. Due to a great income disparity between socio-economic

communities in developing countries, fixing a general rate would be unaffordable for low

income consumers while simultaneously failing to de-incentive misuse and wastage by

higher income consumers . Hence it is important to determine the appropriate rates. The

revision should either be based on consumers’ Willingness To Pay or by determining what

percentage of consumers’ household income would an average water bill be in developed

46

countries with 24/7 supply. In Toronto, the cost of municipal water is set at $2.7/kL (TCC,

2013). Though per-capita water consumption in Canada is much higher compared to

developing countries, an average household consuming 18,600 L would pay $51/month.

According to StatCan as an average Canadian family earns $68,000/year (Canada) (Grant,

2013), the water bill would hence be around 0.9% of the household income. Hence the city

or town must be divided into different metering zones based on the average household

income of consumers in each zone. For instance if the average household income in a

particular metering zone in Bangalore is USD$14000/annum (or USD $1167/month) the

monthly water bill should be around USD$10.5/month (for a stipulated consumption of 155

LPCD). That would mean a fivefold increase in water charge from Rs.6/kL (USD$0.1)

(BWSSB) to Rs. 33.88/kL (USD$0.56). It may seem that the consumers might not readily

accept the new rates, but given the coping costs involved with intermittency they would

likely readily agree if the boards were to promise a much more reliable and continuous

supply. Also billing should seldom be on a flat rate which means Rs. 33.88 /kL that is being

charged is not on a flat rate. Table 4.1 presents a sample set of slab-rates.

Monthly Consumption

Slab rates (Rs./kL)

Slab rates (USD $/kL)

6000 8 0.13

6000 16 0.267

6000 24 0.4

6000 87.5 1.46

Table 4.1

The first column shows the monthly household consumption of 24000 L (200LPCD for a

household with 4 members). The first 18000 L (150 LPCD) would be billed on an average

rate of Rs. 16/kL (USD $0.27/kL) and the remaining 6000 L (50 LPCD) would be billed on a

47

quite exorbitant rate of Rs. 87.5/kL. The variation in the slab rates is aimed at providing the

required amount of water (135-150 LPCD) to consumers at a low rate at the same time

discouraging them from hoarding excess water or wasting. Depending on the average

household income the slab-rates must be modified.

4.4. Model Resource Management Strategies and Long Term Plans

Appropriate distribution management measures will also aid in leakage control and meter

management. Some useful measures, either being planned or already implemented, were

found in the literature (Draft-15, 2000, Rogers, 2008):

a. Maintaining water zones and Meter management: Dividing an area into water districts

and subzones makes management and implementation easier and more achievable. The

first priority is to install meters in zones which would be used to find average

consumption, peak consumption, and leakage losses. Initially in each zone, accurate data

needs to be collected regarding the consumption behaviour, location of water treatment

plants and service tanks, pipeline locations and their alignment, demand pattern of the

zone, and most importantly leakage points and faulty meters (these are done particularly

when converting from intermittent to 24-hour supply). Making use of satellite imagery

and GPS, all data should be co-ordinated and synchronised, helping to better prioritize

key zones. Further, managing pressure so as to maintain equitable distribution will be

more effective if the selected zones are smaller. In a typical case in Badlapur dividing

the supply into operational zones was the key strategy in a complete migration from

intermittent to 24-hour supply (e-gov, 2008). Different operational zones were

demarcated from the other zones based on the storage capacities of the service reservoirs

and consumer withdrawal pattern. The service reservoir supplies water to the

48

Operational Zones. Dividing the operational zones into discrete district metering areas

greatly helped in reducing leakage (as it could easily be detected) and controlling high

flow rates through suitable methods. The model prepared has become crucial for

metering strategy. Costly bulk meters previously used to determine net night flow were

all replaced by this model, which saved an estimated Rs.8 million.

b. Retrofit of existing plumbing and fittings: It is estimated that, by replacing existing

plumbing fittings with more efficient fittings, household and commercial water

consumption can be reduced by an average of 15% to 50% of household and commercial

water use. There are various new innovative ideas in this regard. Plumbing retrofitting

may include fitting dual flush, interruptible toilets, low-flow shower heads, tap

controllers, aerators and user-activated urinals (South African Government Online,

Draft-15, 2000).

c. Economy pumping: Energy costs vary at different times of the day and economy

pumping is a valuable strategy in such areas. Pump Scheduling Systems for water

utilities target load movement from peak to off-peak periods chasing the tariff

differential to achieve energy cost savings (Bunn, 2007).

d. Recommendations for Better Water Resources Management:

Water resource management is crucial for water systems and to society well. Various

strategies are summarized here, many of which are mentioned in the online document of the

South African Government Online (Draft-15, 2000).

1. Source Water Protection: Constant tests should be carried out on water sources and

suitable steps should be taken to maintain the quality. Due to improper urban planning in

most of the developing countries, cities have become so impermeable that few places

49

exist for the rain water to seep into the ground. Hence recuperation or rehabilitation of

water resources, especially groundwater sources, should be implemented in urban areas

of developing countries.

2. Imposing strict penalties on booster pumps and illegal connections: Illegal connections

and booster are one of the main reasons for lost revenue and drop in pressure. Also a

moratorium should be placed on private groundwater usage in regions where sufficient

surface water sources exist. The available groundwater sources must be used by the

municipalities for equitable distribution. The law should therefore strongly enforce the

removal of illegal connections and the fines collected from defaulters must directly go

towards improving the water supply. As reported earlier, if the groundwater usage is

metered and supplied through the municipality, even with the existing rates the water

boards will have an additional revenue of USD $71 million per year.

e. Integrated Resource Planning

Integrated water resource planning and management has become a new model for water

policy development. Global Water Partnership defines integrated water resource

management as “a process that promotes the co-ordinated development and management of

water, land and related resources in order to maximize the resultant economic and social

welfare in an equitable manner without compromising the sustainability of vital ecosystems”

(IRC, 2004).

During the implementation of demand management, the primary focus is to decrease water

demand. This affects the supply management to an extent that the supply can be distributed

to more customers, thus increasing the supply capacity without actually altering the quantity

50

of water provided. Hence this “extra” water has become a “product” due to good planning

and management.

It is important to note that water is normally used for the services derived from it, and not for

the water itself (South African Government Online, Draft-15, 2000). Such applications can

include:

1. Garden Watering: Watering a garden is intended to ensure that plants receive enough

water to carry out metabolic activities. Recycled water thus conserves considerable

potable water while the purpose of gardening is served equally well. Plants should

always be watered in the morning or evening and never during bright sunlight, which

leads to excessive losses. Outdoor potted plants are more exposed to sun and wind and

have only a small amount of potting mix to store water; thus, for water conservation,

ground plants are superior to potted plants.

2. Cooking: Boiling food on an open saucepan consumes substantial water with little

practical use, as most of the water vaporises and leaves the food uncooked. The most

water-efficient way of cooking are microwaving, or steaming using a pressure cooker.

Vegetables boil quicker and it will save water and power.

3. Hand Washing: Elmwood Park (2011) estimates that an average person uses around 1

gallon (3.76 litres) of water each time they wash their hands. Assuming people wash

their hands at least 12 times a day, large amounts of water could be saved if hand

sanitizers are used where the cleansing effect is more pronounced and hygienic, though a

life cycle analysis would be required to determine the water use associated with

production and transportation of the hand sanitizers. More work is also needed to

determine the optimal level of hygiene associated with hand washing.

51

4.5. Model Strategies

Broader strategic measures can also be taken to mitigate the negative effects of intermittent

supply. These model strategies are implemented based on some common prevalent problems.

Solutions through a sample study of Bangalore City have been provided in Chapter 5.

Measures and strategies to meet non potable requirements: Untapped Wastewater

Source-India

Out of about 38000 MLD of sewage generated treatment capacity exists for only about

12000 MLD (CPCB, 2009). Discharge of untreated sewage in water courses, both surface

and groundwater, is the main source of water pollution in India. Out of the 15644 MLD of

sewage generated form the 35 metropolitan cities in India treatment capacity exists for only

8040 MLD (51%). However out of the 35 cities New Delhi and Mumbai have a combined

treatment capacity of 4460 MLD, which is 55% of the total capacity.

Water reuse is the strongest conservation technique: after treatment, sewage water can be

used for various purposes like gardening, irrigation etc.. Israel achieved 65% reuse levels by

2003; almost 50% of the total irrigation sector used treated sewage effluents (Saul, 2004).In

Singapore 50% of the nation’s water needs are met by recycling through the “NEWater”

project. Launched in 2003, the project is aimed at recycling wastewater to purified potable

water in an eco-friendly and cost-efficient way.

Wastewater treatment could be the best option for water scarce countries with high

population density. Waste water treatment can serve two purposes,

52

1) Reduces the dependence on freshwater sources for non-potable purposes

2) Preserves the fresh water sources by preventing it from getting polluted

Though financial constraints and energy shortage have been given as the main reasons not to

adopt wastewater treatment, the cost of losing a precious water source due to pollution or the

cost of finding a new source could be much higher.

4.6. Summary

As water conservations is the key factors that decides how successful the migration can be,

this chapter focuses on conservation right from the consumers’ level. The basic idea

presented here is that if less water is consumed by the users and if water losses are controlled

then the municipality would have sufficient amount of water for a 24 hour supply. Some of

the conservation strategies presented have applied and tested by various municipalities great

results were observed. As mentioned in Chapter 2 lack of financial resources are also

majorly responsible for intermittent systems. Hence this chapter attempts to assess the

possibility of implementing various billing strategies and imposing tariff levels that falls well

within consumers’ WTP (willingness to pay) levels. Further discussion is presented through

a case study in Chapter 5.

53

CHAPTER 5

Case Study of Bangalore and Mumbai

Mumbai and Bangalore are two important cities of India that rose to prominence at different

times in the Indian history. Despite their economic growth, both cities have faced many

challenges, with intermittent water supply being but one of them. With a combined

population of over 28 million (Ray, 2013; PIBS, 2011) this problem should not be

overlooked. However, municipalities and water boards are under the assumption that the

intermittency is saving water and thus helping them overcome water scarcity. Also as the

deleterious effects of intermittent supply are not well quantified, and have become to large

extent accepted as a cultural norm. The following case study closely examines and quantifies

the effects of intermittent supplies in Mumbai and Bangalore with the specific goal of

addressing this complacency.

5.1. Comparative Energy and Cost Analysis of Continuous and Intermittent Supply

Systems – Mumbai, Case Study

Mumbai Water Distribution System Description:

Mumbai, formerly known as Bombay, is the capital city of the Indian state of Maharashtra. It

is the most populous city in India, and the fourth most populous city in the world, with a total

metropolitan area population of approximately 20.5 million, out of which slum population

constitutes 6.5 million. Mumbai lies on the west coast of India and has a deep natural

harbour.

The Hydraulic Engineering Department of Municipal Corporation of Greater Mumbai

(MCGM) is responsible for water supply in greater Mumbai area. In 2005 Mumbai with a

54

population of around 12 million (excluding the slum population), had a water supply

requirement of 3900 Million Liters per Day (MLD) (MCD, 2005). Mumbai’s water supply

was established though various schemes since 1860.

Fig. 5.1 (Source: Uitto and Biswas, 2000): Map showing Mumbai’s various water sources

A brief description of the schemes is as follows (MCD, 2005):

55

a) Vihar Scheme: The Vihar scheme was the first water supply scheme commissioned in

the year 1860 to supply 32 MLD to a population of 700,000. Supply from this source

was later increased to 68 MLD by rising of the dam in 1872 which is still operational

today.

b) Tulsi and Powai Scheme: In 1885 it was decided to develop Tansa as the second

source of water supply but a critical water shortage led to the development of Tansa

lake, upstream of Vihar on Mithi river. This scheme was commissioned to supply 18

MLD though at the same time Powai scheme, which was supposedly so supply 4

MLD is no longer in use due to inferior water quality.

c) Tansa Scheme: The four major sources of water supply to Mumbai city today are

Tansa, Vaitarna, Upper Vaitarna and Bhatsa. The Tansa scheme consisted of four

stages, first stage being completed in 1892 and final stage in 1948. The total water

supply from this stage is about 410 MLD.

d) Lower Vaitarna Scheme: At the end of Tansa scheme in 1948 Mumbai’s water supply

was 495 MLD. But after independence from the British rule India and Mumbai saw a

large influx of people which increased the demand for water supply. Hence the

Vaitarna scheme was planned and completed in 1957 adding 510 MLD to the City’s

water supply.

e) Upper Vaitarna Scheme: The State government in 1960 took up the Upper Vaitarna

scheme. This project was fully commissioned in 1972 and water supply was

increased by 540 MLD.

56

f) Bhatsa Scheme: Due to acute shortages that started arising towards the end of 1960s

Bhatsa scheme was commissioned. The project was implemented in three stages and

in each of these three stages 455 MLD water was drawn from the Bhatsa river.

g) I Mumbai Water Supply Project: At the end of Stage I (or Bhasta Stage I) the total

water supply to the City was 1970 MLD.

h) II & III Mumbai Water Supply Project: At the end of Stage II and Stage III the City

had 2900 and 3400 MLD of water respectively.

5.1.1. System Parameters and Projected Demand

Data pertaining to the system parameters was retrieved from MCD (2005) which elucidates

the city water distribution and sewage plan for the period 2005 to 2025. The City’s

distribution network is being laid and upgraded for over 136 years. The total length of the

distribution mains is about 4000 km with the diameter ranging from 80 mm to 1800 mm.

Though it is known that the mains were either of cast iron or ductile iron the exact length of

pipes corresponding to a particular diameter or type was not available in the literature, and is

likely at least partly uncertain in the field. Yet this data was essential to at least roughly

estimate as it is necessary part of determining head-loss over the years, a value dependent on

the initial roughness which is slightly different for the two materials and strongly dependent

on diameter. To move the discussion forward, these crucial hydraulic variables were

provisionally and indirectly estimated. Ductile iron pipes were introduced in Philadelphia

(USA) (PWD, 2013) and also in the UK in the mid 1960s (Gunter, 2010). Around that time

(mid 1960s) total water supplied to Mumbai City’s was around 50% of the present supply

hence it could be assumed that the distribution mains installed after this period were made of

ductile iron. Sterling et al. (2009) reports that 12.4% of the distribution mains have diameter

57

less than 150 mm, 73% of the mains are less than 250 mm (dia.) and 89% are less than 400

mm. Hence for the present study same scenario was aimed by assigning appropriate lengths

for the respective pipe diameter. Discussing with the local municipal officials and with the

knowledge of the commercially available pipes, for Cast Iron pipes of diameter 200 mm, 300

mm and 1500 mm lengths of 1660 km, 300 km and 80 km were assigned respectively.

Similarly for Ductile Iron pipes with diameter 150 mm and 600 mm lengths of 1660 km and

300 km were assigned respectively, totally adding up to 4000 km of distribution mains. But

after discussing with water board authorities at a pipe replacement site (23rd

May 2012,

Bangalore, India), the total length was divided into pipes with diameter equal to 150 mm,

200 mm, 300 mm, 600 mm, 1500 mm. EPA (2007) reports that 50% of the pipes that

constitute the distribution mains are made of cast iron.

Lifecycle energy requirements for manufacturing DI (Ductile Iron) and CI (Cast Iron) pipes

were retrieved from Du et al. (2012) where the results of corresponding LCA was reported.

The corresponding pipe wall thickness for each diameter was calculated by assuming a

maximum internal pressure of 200 m (Filion et al., 2004) and an operating hoops stress at

half the yield strength (i.e., factor of safety equal to 2).

The study was conducted for a planning period of 100 years. Hence the average population

and demand was projected over the period. The projected water supply and demand for

Mumbai from the year 2001 to 2021 is given below:

Year Supply

(MLD)

Demand

(MLD)

2001 3025 3975

2005 3175 4150

2007 3375 4300

2011 3852 4526

58

2016 4307 4800

2021 5172 5068

Table 5.1

With the above data the demand growth rate (for a period between 2001 and 2021) was

found to be 1.18%. However from 2021 to 2031 the projected population growth is around

0.788% (TRANSFORM, 2005). Also due to stabilization of Indian economic growth, rising

cost of living in Mumbai and increasing opportunities in other cities would divert the growth

to other parts of the country thereby further reducing the population growth rate in Mumbai.

Hence an overall growth rate of 0.3% was assumed for the planning period.

While selecting the time-step it was assumed that all the parameters would remain constant

over the period. A coarse time step was chosen as the variation in parameters like roughness

growth rate, demand, breakage rate, to name a few, cannot be estimated with a shorter time

step. With few available models it was believed that a coarser time step would closer

estimates, and that finer estimates could not be justified in any case. Also the achievable

accuracies in energy estimates with a shorter time step could be negated by uncertainties in

other simulation parameters (Filion et al., 2004).

5.1.2. Consequences of Pipe ageing on Transmission (Pumping) Energy loss

The roughness growth model developed by Sharp and Walski (1988) was used in the present

study to simulate and compare the effect of pipe ageing on net energy expenditure between

the two systems. Sharp and Walski (1988) arrived at the roughness growth model by

combining Hazen-Williams and Darcy-Weisbach equations for head loss. The model relates

Hazen-Williams friction co-efficient to time dependent roughness of pipe.

59

(5.1)

(5.2)

where, C is the Hazen-Williams friction co-efficient, initial roughness height during

pipe installation (new pipe), = the roughness growth rate, t = the number of years since

installation, D = internal pipe diameter, e = time dependent roughness height.

a. Initial roughness height and Roughness growth rate assessment:

Two models developed by Colebrooke and White (1937) and Sharp and Walski (1988) were

initially considered to arrive at the roughness growth rates and they are briefly described as

follows:

With the data gathered from New England Water Works Association (1935), Colebrooke and

White (1937) arrived at the following expression:

2 log a = 3.8 – pH, (5.3)

Or

(5.4)

where a is the roughness growth rate (inch/year). The data in NEWWA (1935) was presented

based on William-Hazen formula which is not velocity independent. Hence to convert it to

Chezy’s co-efficient they had to assume that the velocity was 4 feet/s. However this model

has been described in Colebrooke and White (1937) as “a little better than guess”.

Lamont (1981) presented a thorough set of data that relates Langelier Index with different

trends in roughness growth. Sharp and Walski (1988) compiled the data presented by Lamont

(1981) to arrive at the model described below:

60

(for LI<0) (5.5)

where LI is the Langelier Index.

Langelier Saturation Index (LI), a measure of a solution’s ability to dissolve or deposit

calcium carbonate, is often used as an indicator to corrosivity of water. Though the index is

not related directly to corrosion, it is related to the deposition of a calcium carbonate film or

scale. When no protective scale is formed, water is considered to be aggressive and corrosion

can occur. An excess of scale can also damage water systems, necessitating repair or

replacement.

In developing the LI, Langelier derived an equation for the pH at which water is saturated

with calcium carbonate (pHs). This equation is based on the equilibrium expressions for

calcium carbonate solubility and bicarbonate dissociation. To simulate actual conditions

more closely, calculations were modified to include the effects of temperature and ionic

strength. The Langelier Index is defined as the difference between actual pH (measured) and

calculated .

LSI (or LI) = pH – pHs (5.6)

Where, pH = the measured pH of water and pHs = the pH in the calcite or calcium carbonate

and is defined as

= (9.3 + A + B) – (C + D) (5.7)

Where,

A = (5.8)

B = (5.9)

C = (5.10)

D = (5.11)

61

The magnitude and sign of the LI value show water’s tendency to form or dissolve scale and

thus to inhibit or encourage corrosion. Although information obtained from the LI is not

quantitative, it can be used as a general indicator of the corrosivity of water.

Various sources were examined to retrieve the water quality data for the Mumbai City

required for the calculation of Langelier Index. Chandra et.al., (2012) assessed the drinking

water quality in Mumbai (Vihar lake) among other Indian cities. The assessment presents,

pH, Total Dissolved Solid (TDS), average Temperature, water hardness and alkalinity in

Vihar Lake.

Initial roughness height ( ) is another important parameter needed to implement the model

proposed by Sharp and Walski (1988). Sharp and Walski (1988) report the initial roughness

height ( ) to be 0.18 mm for a new metal pipe with sizes ranging from 150 mm to 600 mm

(dia.). These values were further used for Life Cycle Energy Analysis by Filion et. al.,

(2004). Lamont (1981) recommends typical values of initial roughness height to be 0.25 mm

for Cast iron (CI) pipes. Hence an initial roughness height of 0.18 mm was used for DI pipes

(with diameters ranging from 150 mm to 600 mm) and 0.25 mm for CI pipes of all sizes.

Another important factor that dictates the value of friction head-loss in pipe systems is the

volume flow rate (

). Estimating the flow-rate in a continuous supply system is relatively

a straightforward process due to the available hydraulic models and constantly monitored

networks. But in an intermittent system various factors like availability of water, power

shortages, uncertainty in the duration of supply, varying peak factors and constant pipe bursts

significantly influence the flow rate. With a large volume of water being supplied through a

short time span, minor changes in the supply duration would greatly affect the flow-rates.

Hooda and Desai (2012) in their techno-economic feasibility study of a water supply scheme

62

in Upper Vaitarna (Mumbai) estimate the flow velocity to be 1.25 m/s. Andey and Kelkar

(2007) compare the performance of systems in India during intermittent and continuous

supplies. This interesting study compared the average flow-rates during the supplies. From

the reported values the flow-rate ratio (intermittent to continuous) in four cities ranged from

1.27 to 5.26. Hence in the present study it was assumed that the average flow rate in an

intermittent system would be 1.27 times that in a continuous system.

As discussed earlier in this chapter, intermittent flow creates an ideal situation inside the

distribution system to assist and accelerate the process of corrosion. Though there is ample

evidence in terms of rapid deterioration of infrastructure, high leakage and breakage rates

surprisingly, no study has been carried out to estimate the higher levels of corrosion or the

increase in roughness growth rates in an intermittent system.

As it is expected an increase in the roughness height/growth rate would reduce the Hazen-

Williams co-efficient considerably resulting in an increased head-loss, which means the

pumps should need more energy to lift the same volume of water. In simple mathematical

terms the energy difference (between continuous and intermittent systems) is expressed as:

W = (5.12)

where,

W = Net conveyance energy difference between continuous and intermittent systems, =

Density of water (1000 kg/ ), g = Acceleration due to gravity or gravitational constant (9.8

), = total dynamic head delivered by the pump in a continuous supply system, =

total dynamic head delivered by the pump in an intermittent supply system, Q = Total

volume of water delivered by the pumps ( ), = Pump efficiency.

63

b. Pipe Replacement

Researchers, over the years have tried to link the occurrence of pipe breaks and leaks with

ageing. As mentioned earlier many factors are responsible for pipe breaks and the extent to

which they influence actual breaks inevitably varies from case to case. For instance if the

large difference in temperature is in a way responsible for pipe breaks and leaks in colder

countries, negative pressures and frequent water hammer pressures may have a larger impact

in tropical countries. Hence as data on such factors is scarce and not to mention the difficulty

in accounting for various other intrinsic factors, researchers have relied on statistical

approaches to simulate pipe breaks in the systems. The values for the growth rate were

gathered from various studies and compared to arrive at a typical value. A brief description

of the literature reviewed is presented below. Shamir and Howard (1979) describe a

procedure that uses the history of main breaks to forecast how the number of breaks would

change with time if the pipe were not replaced and a separate analysis predicts the failure of

newly installed pipes.

(5.13)

where, is the number of breaks in a pipe i after t years of replacement; is the

breakage growth rate (increase in the number of breaks per year); is the year 0 or the year

of replacement; is the number of breaks in the pipe i in the year of replacement.

The exponential relationship between the pipe breakage rate and their age developed by

Shamir and Howard (1979) was further applied with minor fine-tuning by Walski and

Pellicia (1982) to provide a cost analysis for pipe replacements and breaks. Clark et al (1982)

developed a linear equation to determine the time from pipe installation to the first break and

an exponential equation to determine the breakage rate after the first break.

64

It has to be understood that these models developed over years are valid for continuous

supply systems and do not take into account the intermittency in supply conditions. As the

study here is focused on intermittent systems the approach was modified to accommodate the

intermittency factor. For such an attempt to be successful data must be collected from a

typical scenario of a system that has been transformed from (or to) an intermittent to (or

from) a continuous supply system. Pipe break data from such a system must be collected

before and after the transformation. Charalambous (2011) collected the data from such a

scenario that occurred due to severe water shortage in Lemesos, Cyprus, in 2008/09. In the

study conducted by Charalambous (2011) it was evident that there was a large increase in the

number of reported pipe breaks during the period of intermittent supply. In order to quantify

these a comparison was made by Charalambous (2011) for a large number of District

Metered Areas, 20 in total, between the breaks reported in 2007, before the intermittent

supply was applied, and those reported in 2010, the first year immediately after the measures

were lifted. This comparison showed that the number of breaks on mains increased from an

average of 1 per 7.14 km of mains to 1 per 2.38 km of mains, an increase of 300%. If the

above figures are translated to the number of breaks per unit length the increase would be

from 14 breaks/100 km to 42 breaks/100 km. It should be noted here that in the above case

the system was operated continuously though the rationing occurred just for a period of three

years. Pipes in a system which has always been operated intermittently corrode faster than

pipes in a continuous supply system. Hence in such a (continuous) system where the rate of

deterioration of pipes is far less compared to a system that is operated intermittently by

default, the increase in breakage rate was observed to be 300%. Also in an intermittent

supply system the leaks and breaks often do not surface and hence go undetected as the

65

system is not pressurised. To make the situation worse, most cities in countries like India

where people are grappling with water related problems, have highly unreliable data

collection records. Based on the facts gathered from WSP (2008) only Jamshedpur,

Bhubaneshwar, Bangalore and Hyderabad have maintained an acceptable record of pipe

breaks. However even the available data from a few Indian cities show that the breakage

rates are enough to warrant concerned. Breaks occurred in Bangalore and Hyderabad at the

rate of 5.23 per km and 3.97 per km respectively (WSP,2008), which is quite high when

compared to the situation in industrialized countries like Canada where the number of breaks

range from 0.098 to 0.367 per km depending on the pipe material (NRCC, 1993). Hence it is

evident that though Charalambous (2011) noted just a 300% rise in the number of breaks, in

a system that is operated intermittently by default the number is easily over 10 times that of a

continuous pressurised system. For the case of continuous supply system the values for the

initial break rate were taken from the literature reviewed. In a similar study presented

by Filion et al. (2004) a typical initial break rate of 0.04 break/km/year was applied for all

steel pipes in the NYC water supply system.

With the data retrieved from the reviewed literature and the findings presented by

Charalambous (2011) the initial break rate of 0.07 break/km/year was applied for intermittent

supply.

The breakage growth rate in Shamir and Howard (1979) is reported to have a range

between 0.01 to 0.15 /year but a typical value is stated to be 0.05 breaks per year. Clark et al.

(1982) reported the value of to be 0.086 /year and according to Kleiner and Rajani (1999)

the values range from 0.003 to 0.134 breaks/ year for pit and spun cast-iron. In a similar

study done by Filion et al. (2004) on the water distribution in NYC, a breakage rate of

66

0.07/year was applied. In the present study a slightly different approach was adopted to

arrive at a typical growth rate value for the IS system. A relatively up-to-date data on

breakage rates in the Indian city of Bangalore was presented by WSP(2008). Bangalore was

chosen as the data collected from Bangalore Water Supply and Sewage Board (BWSSB) was

considered to be highly reliable according to WSP (2008) though reliable data on network

performance (specifically on pipe breaks) was supposedly maintained only from 2006.

By applying an initial break rate of 0.07/km/year (for IS) and with the knowledge of average

age of water mains, growth rate value were back-calculated using the model presented by

Shamir and Howard (1979) for which the average age of water mains were required. The age

of water mains were not available in the literature but Bangalore Water Supply and Sewage

Board (BWSSB(website), 2013) in their pipe replacement scheme have reported the supply

lines to be 50-60 years old. Pipes in Hyderabad (India) are 60-70 years old on an average and

oldest pipes are 100 years old (Mohanty et al. 2003). Also, Shivakumar (2013) reports that

pipes in Bangalore were laid from over 50 years ago. Hence average is age of water mains

were taken to be 50 years while calculating the annual breakage growth rate. The typical

value for IS systems was hence found to be 0.09 breaks/year.

The energy required to replace a unit length of pipe was found by simply multiplying the

energy required to fabricate a pipe of a particular diameter and thickness by a typical break

length.

(5.14)

where, = the average length of break (m), = fabrication energy per unit length (MJ/m)

Integrating the formula in equation (3.6.13), over a replacement cycle T gives the total

number of breaks in the pipe as

67

B =

(5.15)

where, B = Number of pipe breaks per replacement cycle, L = Length of pipes, x = dummy

variable.

Combining the above three equations (3.6.13,.14 &.15) and taking into account the

replacement cycle for each pipe-set considered the total energy required to repair pipes in the

system can be estimated ast:

(5.16)

Where, = Total energy required to repair pipes in the system (J), M = number of

replacement cycles throughout the planning period.

Data on typical length of pipe that would be replaced (repaired) during a break was not

readily available in the literature. Hence by assuming that repairing the pipes involves the

same activities as replacing them (Filion et al., 2004), a break length was calculated.

Pipe replacement would involve energy and material needed for soil excavation and

restoration, transportation of materials and operation of machinery. As relevant data on

energy consumption during the above activities is not available in the literature energy

involved during the fabrication process was multiplied by a factor of 2 (based on a similar

study by Filion et al., 2004). Shamir and Howard (1979) used a replacement cost of $164/m

and repair cost of $1000/break but these values do not account for the fact that cost varies

with pipe sizes. Walski and Pelliccia (1982) provide the required data on repair and

replacement costs for different pipe sizes.

68

5.1.3. Analysis of the results

The motive behind conducting this study was to establish concrete evidences that could

prove that maintaining an IS system is not energy and cost efficient. As most IS systems are

prevalent in developing countries which have recently found a need to improve the water

supply, retrieving relevant data was not straightforward. For instance Bangalore is expected

to have an up-to-date record of the network parameters but the BWSSB only started

maintaining a computerised database in 2006 (WSP, 2008). However with the available

datasets, studies and models it was able to establish a connection between service

intermittency, corrosion and water main breaks.

Fig. 5.2

The above Figure 3.6.4 compares the cost incurred in conveying water from the pumping

stations to the consumers in an intermittent and a continuous system. The increase in

corrosion levels in an IS system results in an increase in energy consumption at the pumping

station. The study provided some startling results by quantifying the disastrous effects of

intermittent supply. Pressurising water in an intermittent system seemed to be a costly affair.

0

0.5

1

1.5

2

2.5

3

3.5

10 20 40 50 70 100

Continuous Supply

Intermittent Supply

Pumping Cost Comparison (CS vs IS)

C

ost

($

B U

SD)

Replacement Period (Years)

69

For instance 72% more energy (and hence revenues) would be required to pump water in a

10-year old intermittent system compared to CS system of the same age. As the pipes in the

system get older, the gap between the energy needed to maintain the two systems also

increases. Hence, in a 50-year old system maintaining an intermittent supply would need

84% more energy. Increasing losses due to continued inaction is shown in Fig. 3.6.5. The

results however were very sensitive to the flow-rates applied. Even when the lower limit of

the range of flow-rates ratios (1.27) reported by Andey and Kelkar (2007) were applied,

significant differences in the energy requirements were observed. However, if the flow-rates

are assumed to be same for both the supplies, which is never the case with intermittent

supply, transmission energy requirement for intermittent supply would plummet and would

only be 11 % higher for a 10 year old system. This behavior is enough evidence to disprove

the commonly accepted fact that, intermittency and shorter supply duration are energy saving

strategies.

Fig. 5.3

0

10

20

30

40

50

60

70

80

90

100

0 20 40 60 80 100 120

Percentage Loss

Per

cen

tage

Lo

ss (

Savi

ng)

(%

)

Replacement Period (Years)

70

The study reports another major drawback of IS system discussed earlier. Charalambous

(2007) reported a 300% increase in the number of breaks in a system that was operated

intermittently on a temporary basis. However nowhere else in the literature was a connection

between watermain breaks and intermittency quantified. Hence this study establishes an

important link between intermittency in supply and increasing watermain breaks. Cost

involved in repairing pipe breaks are compared and reported in Fig. 3.6.6. A log-scale was

used only to fit the values in a smaller range due to the exponential nature of the pipe-break

model used. A significant difference in the repair/replacement costs is reported. For instance

costs involved in repairing 20 and 40 year old mains in a IS system were 2.6 and 3.9 times

more, respectively. But if the replacement cycles within the 100 year planning period are

taken into account, costs involved for maintaining IS systems are over 6 times of what is

required for maintenance in a CS system. Though at replacement periods over 70 years the

pipe break values are purely theoretical, costs involved in pipe replacements are very high.

For a system with 40 year old mains it costs almost $2.8 Million (USD) to repair pipes is IS

system as against $0.73 Million (USD) that would be spent otherwise. This also means

hypothetically if a 40 year old system in Mumbai is operated continuously, with the available

funds of $2.8 Million, pipe repair plans could be delayed easily by over 10 years. As more

frequent system overhauls are required to maintain an IS system, it is definitely not a cost

effective option. Fig. 3.6.8 shows the expected saving through a successful migration to 24/7

supply.

71

Fig. 5.4

It is true that during pipe breaks considerable cost is involved repairing/replacing damaged

pipes but they pose a bigger problem by wasting large volumes of water. Also the net energy

expenditure during the replacement process is a serious cause of concern. Due to higher

frequency of breaks, energy requirement for maintenance (replacement/repair) of an IS

system can be several times the requirement for a CS system. With soaring gas and

electricity prices and shortage of supply meeting such requirement would mean incurring

more costs or cutting down on other important tasks. For instance repair of pipes in a 40 year

old system (such as the one consider in Mumbai) would require 3 times more energy if the

supply is intermittent.

0

1

2

3

4

5

6

7

8

9

10

10 20 40 50 70 100

Continuous Supply

Intermittent Supply

Cost of Repair (CS vs IS) C

ost

in $

USD

(Lo

g sc

ale)

Replacement Period (Years)

72

Fig. 5.5

Number of breaks and hence the cost involved drastically increases with the replacement

period, especially for intermittent supply. For instance if in a 20-year old system, the ratio of

the number of breaks (IS:CS) is around 2.5, in a 50-year old system the ratio would be

around 5. With the average age of watermains in many Indian cities being around 50-years it

could be imagined that the municipalities would be shelling out five times more of tax-payers

money to repair pipes, solely due to intermittent supply. In the considered scenario, to repair

pipes in a 50-year old IS system it would cost over a USD $11 million more.

0

2

4

6

8

10

0 20 40 60 80 100 120

Estimated Cost Saving (Pipe breaks)

Co

st (

$ U

SD)

(lo

g sc

ale)

Replacement Period (Years)

73

Fig. 5.6

Fig. 5.7

So far the effects of intermittency have been quantified in terms of direct costs involved or

energy required. But subsequent impacts such as water losses due to deteriorated system and

innumerable cases of inconvenience caused to the public during frequent pipe breaks or

0

2

4

6

8

10

12

14

10 20 40 50 70 100

Continuous Supply

Intermittent Supply

Pipe repair Energy Consumption Comparison (CS vs IS)

En

ergy

Co

nsu

mp

tio

n (

J) lo

g sc

ale)

Replacement Period (Years)

0

2

4

6

8

10

12

0 20 40 60 80 100 120

Ratio of Energy Requirement (IS:CS) (Replacement/Repair)

Rat

io (

IS:C

S)

Replacement Period (Years)

74

replacement processes need much more attention. Mumbai has the highest amount of water

loss in India which some reports claim to be around 40% to 50% (including pilferage)

(Sharma, 2011). According to Delhi Jal Board of 3000 MLD supplied to the City (New

Delhi) only 1700 MLD reaches consumers due to infrastructure constraints and other

problems (Bhatnagar, 2010).

5.2. Sample study on Bangalore City:

Bangalore produces 770 MLD of sewage (CPCB, 2009) out of which only 300 MLD is

treated (Shilpa, 2011). However even out of the 300 MLD treated only 9 MLD is being put

to some use (Shilpa, 2011) while the rest is just released into the city drains. Hence 98.83%

of the sewage is released into the valley and does not contribute to any water source.

Wastewater treatment in Toronto should be a model for Bangalore. The Ashbridges Bay

Wastewater Treatment Plant (ABTP), built in 1910, is Toronto's main wastewater treatment

facility and the largest such plant in Canada. It treats, on average, 9.5 m3.s

-1of wastewater

through a series of processes which includes screening, grit removal, primary treatment,

secondary treatment by a conventional activated sludge process, chemical phosphorus

removal and chlorine disinfection of treated effluent (Dziedzic et al., 2013). The projected

capacity of the plant is almost five times its current flow, though not all pumps can be

operated simultaneously due to power constraints and flooding concerns.

ABTP was chosen for comparison here because of its high COD removal rate of 97%

(Dziedzic et. Al., 2013). As COD determines the amount of organic pollutants in water

(surface or wastewater) it is a useful measure of water quality. The operation phase alone

75

which consumes around 500 TJ/year constitutes 92% of the Life-Cycle Energy consumption

at ABTP (Dziedzic et al., 2013).

At present much of Bangalore’s supply is from River Cauvery which is 90 kms from the city

and 500 m below it (Srinath, 2013). Hence even if fluid friction is not taken into account, to

just get the water from the river to the city 2600TJ of energy is being consumed. It is also

known that from its 312,000 borewells the City draws 300 MLD of water (Nataraj, 2013).

Average depth of the borewells in the city being 200m, over 200 TJ of energy is consumed

(mostly by residents) in pumping the groundwater annually. Hence to meet the demand,

tapping 1400 MLD of surface water and 300 MLD of groundwater, 2800 TJ/year of energy

is required.

If treating 821 MLD (299.59 MCM/year) of waste water in Toronto requires around 500 TJ

of energy per year, to employ the same level of treatment in Bangalore the net energy

required to operate the wastewater treatment plant should be around 470 TJ/year. Which is

any way is around 1/6th

of the present consumption (2763.23 TJ/year).

Table 4.1 (CPHEEO, 1999), shows the breakup of per-capita water consumption as defined

by the Ministry of Urban Development. Around 44% of per-capita needs are for non-potable

purposes. Thus if 50% of current freshwater consumption is offset through wastewater reuse,

800-1000 TJ/year of energy benefits could be achieved.

Per-Capita consumption

Bathing 55

Cooking 5

Drinking 5

Washing Clothes 20

76

Washing Utensils 10

Cleaning of house 10

Flushing 30

Total 135

Table 5.2

Wastewater treatment and reuse seems like the perfect solution to solve the water scarcity

issue but it is possible to achieve further energy benefits. For instance, a 10 MW biogas co-

generation plant was planned in Toronto to flare up the biogas released during the treatment

processes (Hamilton, 2010). Hence through the co-generation plant in ABTP, around 315

TJ/year of energy could be reused within the plant. If biogas co-generation is hence

implemented in Bangalore, 300 TJ/year of energy is put to use for operation of the plant, net

energy for treatment could be further reduced to 155 TJ/year (from 470 TJ/year).

5.3. Summary

So far it has been established that intermittent supply destroys the main purpose it was

employed in the first place. The more municipalities wait without planning a complete

migration towards employing a continuous supply system, the harder it gets to manage as the

system would further deteriorate and more water will flow out through leaks and breaks

without reaching the consumers. The study thus quantifies the effect of a continued inaction.

The systems are ageing and the infrastructure has deteriorated faster than it should. As it has

reached a point where most pipes have to be replaced this would be the best time to

implement strict measures and plan for a complete migration. The net energy and cost benefit

achieved from maintaining a continuous supply could be used as investments to implement

wastewater reuse in phases. For instance by assuming that 100% of the meters in Bangalore

are metered, with the current rates USD $52 million would be recovered but with the revised

77

rates proposed USD $293 million in revenue could be earned. The fivefold increase in the

revenues would hence assist in a successful migration to 24-hour supply and implementation

of wastewater reuse. The only concern with the implementation of wastewater recycling is

that separate water lines need to be installed for the freshwater supply for potable purposes

which would need massive initial investments. However as the present infrastructure has

deteriorated pipe replacements are anyhow necessary. Hence it would be an ideal time to

invest in additional infrastructure and simultaneously implement measures to implement 24-

hour supply successfully. Wastewater reuse can also be implemented in phases.

One of the most challenging and time consuming step in the above estimations was

collecting and estimating the actual data such as water consumption, pipe characteristics,

non-revenue water, number of borewells and pipe breaks. If accurate data is not maintained

then the system cannot be modelled (both physical and computer based) for better

management and maintenance. For instance Bangalore started maintaining data on pipe

breaks from the year 2006. Estimated data based on previously developed mathematical

models could be good for an analysis of the existing condition similar to the one presented

here but more accurate field values would be needed for planning and implementation.

78

CHAPTER 6

Conclusion and Future Avenues of Research

This thesis provides enough evidence to prove the disastrous effects of Intermittent Water

Supply System on the consumers and on the associated distribution infrastructure. For the

following reasons a complete migration to a 24 hour supply is highly recommended. Note

that although these points are framed particularly for India, the problems mentioned are as

broad as intermittent supplies themselves.

1) The IS system can never be a solution to water scarcity, as it is thought to be. In fact,

the truth is higher that the higher the degree of intermittency the higher is the

tendency of the consumers to collect and hoard more water, thus increasing their

consumption. Moreover, intermittency often leads to much higher rates of water loss

from leakage and breaks. It seems perhaps logical to expect that the per capita

consumption will be less in water scarce situation. Ironically, this is often not the

case: when the supply is intermittent per capita consumption is higher.

2) Unequal distribution of water to consumers is unacceptable. It has brought conflict

and tensions between communities in India as the consumers simply cannot accept

that someone else is getting a better water supply when everyone pays the same price.

3) Today the biggest challenge in rural India is intermittency in supply. To cope the

rationing the direct and indirect costs incurred by the consumers is more than what

consumers in the developed world would for a 24 hour supply. This is seriously

affecting the economy of developing countries like India. Young boys and girls who

should be spending time at school or working for hourly wages are sacrificing their

time and also the best part of their lives just to secure water for their families.

79

4) As mentioned earlier, urban India attempts to cope with intermittent systems either

through private borewells or tanks. This unfair edge given to some sets of the

population creates a further rift within communities. It is gives an incentive for

people to take advantage of the system. For instance, landlords are taking advantage

of intermittent supply by charging very high rent if tenants require continuous supply

through private borewells. An unfair increase in property rates is a common reaction

in urban India which is also a result of unequal distribution of nature’s resource.

5) A huge amount of water is being lost through leaky pipes, breaks and bursts. IS

system not only stifles the consumers’ everyday activities, but is rapidly destroying

the existing physical systems. With the current shortage of revenues, coping with

more frequent replacement and repairs is a distant dream which means losses

continue to exist with municipalities doing nothing about it. When it is no longer

feasible to supply water through distribution lines, water trucks and tanks would be

used for water distribution.

6) Water quality deterioration occurs at different levels during intermittent supply and

this extends right from intrusions into distribution mains during negative pressure

regimes to arsenic contamination associated with use of marginal groundwater. Often

consumers are not aware of the repercussions of consuming contaminated water or

they are not aware about the contamination. Serious health related issues arising out

of such negligence are common in most developing countries with intermittent water

supply.

7) As if these problems were not sufficient, intermittent system is a dangerous option

during fire events. Not only are the available pressures unfit for firefighting but often

80

during fire accidents the particular region may not even be receiving water at that

moment! Transporting water through via trucks through the congested roads means

delays response and leads to more destruction and losses during fire accidents.

Hence as intermittent systems do not serve any purpose what-so-ever, the municipalities

should urgently and decisively plan for a complete migration to a 24 hour supply.

Some possible future works that would further optimize water distribution are as follows,

1) Maintaining and keeping better records of water use, infrastructure system

investments and system performance. It is very hard to plan well is data is inadequate,

lacking, uncertain or poorly organized.

2) Droplet size analysis in developing water efficient fire suppression systems

3) Creating a framework to assist the formation of water zones to successfully

implement water charges based on the household income

4) Region-wise groundwater studies to implement appropriate reclamation methods.

5) Developing cost efficient wastewater treatment strategies

6) Developing interactive water usage tracking method for consumers where the

household water usage can be monitored on an hourly basis. For example, an

interactive Smartphone application could help users track their water usage from any

location which would help to stop excess usage and plug leaks instantly.

7) Performing Life-Cycle Energy (& Cost) Analysis of using Biogas generated from

wastewater treatment to desalinate sea water. For instance a model could be

developed to determine the volume of seawater that can be desalinated in coastal

cities (such as water starved Chennai) with only biogas generated form wastewater

treatment from the city.

81

References

*Numbered references are used for articles that are not published in conferences or journals but were

retrieved through reliable sources.

[1], Rossum, J.R., “Fundamentals of Metallic Corrosion in Fresh Water”, Roscoe Moss Company. World

Wide Web Link: [http://www.roscoemoss.com/tech_manuals/fmcf/fmcf.pdf]. Accessed on 2 July 2013.

[2], Kok, M.V., Chapter 9, Course ID: PETE424, Middle East Technical University, Petroleum and Natural

Gas Engineering Department. World Wide Web Link:

[http://www.metu.edu.tr/~kok/pete424/PETE424_CHAPTER9.pdf]. Accessed on 2 July 2013.

[3], , “New Water Management System in Cape Town”, World Wide Web Link:[

http://unpan1.un.org/intradoc/groups/public/documents/cpsi/unpan028433.pdf ]. Accessed on 2 August

2013.

[4], Babu, R.J., “Fire Audit- A Forward Looking Approach”, Cholamandalam MS Health Risk Services,

World Wide Web:[ http://www.cholarisk.com/uploads/fire_audit.pdf ]. Accessed on 5 July 2013.

“e-gov” 2008, Asia’s first magazine on e-Government, Available:

[http://egov.eletsonline.com/2008/08/solution-for-24x7/]. Last Accessed on Feb. 29, 2012.

Agbenowosi, N.K., “A Mechanistic Analysis Based Decision Support System for Scheduling Optimal

Pipeline Replacement”, a Ph.D thesis submitted to and approved by Virginia Polytechnic Institute and State

University, September, 2000.

Albertson, M. L., and Andrews, J. S.,1971, ‘‘Transients caused by air release.’’ Control of flow in closed

conduits, Edited by J. P. Tullis , Colorado State Univ., Fort Collins, Colorado, 315–340.

Anand, S., Vairavamoorthy, K., “GIS in Design and Asset Management of Intermittent Water Distribution

Systems”, 2002.

Andey, S.P., Kelkar, P.S., “Performance of water distribution systems during intermittent versus

continuous water supply”, Journal (American Water Works Association), Vol. 99, No. 8, pp. 99-106,

August 2007.

Asian Water Development Outlook (AWDO), 2007, “ADB Water for All-Asia Pacific Water Forum-

Country Paper Pakistan”, AWDO is the new publication commissioned by the Asian Development

Bank(ADB).

82

Baliga, L., “One lakh more water meter planned for island city”, The Times of India article, 29 Feb. 2012.

World Wide Web Link:[ http://articles.timesofindia.indiatimes.com/2012-02-

29/mumbai/31110244_1_meter-system-flat-water-tax-water-connections ]. Accessed on 5 July 2013.

Bhatnagar, G.V., “Tragedy of Delhi’s Water Loss”, A The Hindu report. 7 January 2010. World Wide Web

Link:[ http://www.thehindu.com/todays-paper/tp-national/tp-newdelhi/the-tragedy-of-delhis-water-

loss/article678791.ece ]. Accessed on 4 July 2013.

Bose, A.R.J.C., Neelakantan, T.R., Mariappan, P., “Peak Factor in the Design of Water Distribution

System- An Analysis”, International Journal of Civil Engineering and Technology (IJCIET), Vol. 3, Issue

2, pp 123-129, 2012.

Brooks, N., “Imminent Water Crisis in India”, World’s Biggest Problems, 2007. World Wide Web Link:[

http://www.arlingtoninstitute.org/wbp/global-water-crisis/606 ]. Accessed on 5 July 2013.

Bunn Simon., 2007, “Greenhouse gas reduction as an additional benefit of optimal pump scheduling for

water utilities”, Water Environment Federation.

BWSSB, “Current Projects”, 2013. World Wide Web Link:[ http://bwssb.org/current-projects-4/ ].

Accessed on 7 August 2013.

Charalambous, 2012, “Effects of Intermittent supply on water distribution networks”, Waterloss

Conference, Feb. 26-29, Manila.

Chandra, S., Singh, A., Tomar., P.K., “Assessment of Water Quality Values in Porur Lake Chennai,

Hussain Sagar Hyderabad and Vihar Lake Mumbai, India”, a Chemical Science Transactions Research

Article, Department of Chemistry, Zakir Husain College, University of Delhi, 30 May 2012.

Charalambous, B., 2011, “Hidden costs of resorting to intermittent supplies”, Water Supply Networks and

Pipelines, Published in IWA Water 21, December.

Charng, T., Lansing, F., “Review of Corrosion Causes and Corrosion Control in a Technical facility”,

TDA Progress Report 42-69, DSN Engineering Section, March-April, 1982.

Chennai Metro Water, World Wide Web link

[http://www.chennaimetrowater.tn.nic.in/departments/finance/tariff.htm]. Last Accessed: Aug. 14, 2012.

Choe, K., Varley, R., Bijlani, H.U., 1996, Environmental Health Project, Activity Report No.26, “Coping

with intermittent water supply: Problems and Prospects”. Prepared for the Regional Housing and Urban

Development Office, New Delhi and the Global Bureaus Centre for Population, Health and Nutrition,

Office of Health and Nutrition, Environmental Health Division; and the Centre for the Environment, Office

of Urban Programs, U.S. Agency for International Development under EHP Activity No. 193-CC.

83

Clark, R. M., Stafford, C. L., and Goodrich, J. A. ~1982!. ‘‘Water distribution systems: A spatial and cost

evaluation.’’ Journal Water Resource Planning and Management, 108(3), 243–256.

CPCB, 2009, “Status of Water Supply, Wastewater Generation and Treatment in Class-I cities and Class-II

towns of India”, Central Pollution Control Board, Ministry of Environment and Forest, Government of

India, 24 Dec. 2009.

CPHEEO (Central Public Health Environmental Engineering Organization), 1999 (3rd ed.). Manual on

Water Supply and Treatment. Ministry of Urban Development, Government of India, New Delhi.

Colebrooke, G.F., White, C.M., “The Reduction of Carrying Capacity of Pipes With Age”, J. Inst. Civil

Eng. London, Vol. 10 pp 99, 1937.

Du, F., Woods, G., Kang, D., Lansey, K., and Arnold, R., ”Life Cycle Analysis for Water and Wastewater

Pipe Materials.” J. Environ. Eng., 139(5), 703–711, 2012.

Deepthi, M.R., “Sucking groundwater dry”, DNA Report, 19 March, 2013. World Wide Web Link:

[http://www.dnaindia.com/bangalore/1812914/report-sucking-groundwater-dry]. Accessed on 5 July, 2013.

DFID, “Community Management of Groundwater Resources in Rural India”, British Geological Survey

Commissioned Report, Department for International Development, NERC, 2005.

Elmwood Park, Village of Elmwood Park: Water Usage Facts. Available:

[http://www.elmwoodpark.org/water/Facts.htm]. Last accessed: Jan. 20, 2011

Environment News Service, 2003, “100 New Commitments Pour in as Water Forum Closes”, Kyoto,

Japan, March 2003 by Environmental News Service (an International Daily Newswore).

Available:[http://www.ens-newswire.com/ens/mar2003/2003-03-24-04.html].Last accessed: 29th February

2012.

EPA, “Distribution System Inventory Integrity and Water Quality”, Prepared by American Water Works

Association, 2007.

EPA, 2004, “Drinking Water Costs and Federal Funding”, Environmental Protection Agency, June,

Available:

[http://water.epa.gov/lawsregs/guidance/sdwa/upload/2009_08_28_sdwa_fs_30ann_dwsrf_web.pdf]. Last

accessed: Aug. 14, 2012.

EPA, 2008, “Indoor Water Use in the United States”, Environmental Protection Agency, June, World

Available: [http://www.epa.gov/watersense/docs/ws_indoor508.pdf]. Last accessed: Aug. 14, 2012.

84

Evison, L., Coelho, S.T., Jayyousi, A., Sunna., N., Hashwa, F., “Control of Bacterial Regrowth in water

supply distribution systems in water short European and Mediterranean countries”, Reconciling Multiple

Demands on Coastal Zones, Summary of the Final Report, 4th Framework Program, 2001.

Evison, L., Sunna, N., “Microbial Regrowth in Household Water Storage Tanks”, American Water Works

Association, Vol. 93, No. 9, pp. 85-94, 2001.

Expressindia, 2009, “Average Indian’s income crosses Rs. 3000”, May 29th. Available:

[http://www.expressindia.com/latest-news/Average-Indians-income-crosses-Rs-3000/468084/]. Last

accessed: Aug. 14, 2012.

ET, “India's GDP growth to be between 6-6.3% in this fiscal year: Simon Godfrey, BNP Paribas

Investment Partners”, an Economic Times article, Oct. 10, 2012. World Wide Web Link:[

http://articles.economictimes.indiatimes.com/2012-10-10/news/34363487_1_simon-godfrey-fiscal-deficit-

gdp-growth]. Accessed on 13 Sept. 2013.

Fabbricino, M., Panico, A., Trifuoggi, M., 2005, “Copper Release in Drinking water due to Internal

Corrosion of Distribution pipes ” Global NEST Journal, Vol 7, No 2, pp 163-171.

Filion,Y.R, MacLean, H.L, Karney, B.W, “Life-Cycle Energy Analysis of a Water Distribution System”,

Journal of Infrastructure Systems, ASCE, September 2004.

Fishman, C., “The Big Thirst: The Secret Life and Turbulent Future of Water”, 2011.

Ghosh, N.C., Singh, R.D., “Groundwater Arsenic Contamination in India: Vulnerability and Scope for

Remedy”, A Central Ground Water Board Report and presented at ICID Conference, December 2009,

World Wide Web Link:[ http://www.cgwb.gov.in/documents/papers/incidpapers/Paper%208%20-

%20Ghosh.pdf ]. Accessed on 5 Aug 2013.

Global Water Intelligence, “The cost of coping with intermittent supply in India-Chart”, Volume-10, Issue-

5, May, 2009. Available: [http://www.globalwaterintel.com/archive/10/5/analysis/chart-month.html]. Last

accessed: Feb. 29, 2012.

Grant, T., “Middle-class income stagnation, made in Canada”, a The Globe and Mail article. 27 June 2013.

World Wide Web Link:[ http://www.theglobeandmail.com/report-on-business/economy/economy-

lab/middle-class-income-stagnation-made-in-canada/article12858848/]. Accessed on 28 September 2013,

Gunter, P., “Beyond Nuclear Comments Regarding Generic Aging Lessons Learned (GALL) for Age

Management Programs for Buried and Underground Pipes (XI.M41)”, 2010,

85

Gupta, Y.P., “Poor Water Quality a Serious Threat”, A Deccan Herald report. World Wide Web Link:

[http://www.deccanherald.com/content/63740/poor-water-quality-serious-threat.html]. Accessed on 9 Aug.

2013.

Hamilton, T., “Hamilton: Finally, a plan to use Toronto’s biogas”, 26 April 2010. The Star article. World

Wide Web Link:[

http://www.thestar.com/business/tech_news/2010/04/26/hamilton_finally_a_plan_to_use_torontos_biogas.

html ]. Accessed on 5 July 2013.

Holley, E.R., 1969, “Surging in a Laboratory Pipeline With a Steady Inflow”, ASCE, Journal for Hydraulic

Engineering 95(3), 961-979.

Hooda, N., Desai, R., “Piped Water Supply Scheme based on Upper Vaitarna for tanker fed villages in

Mokhada Taluka: A Techno Economic Feasibility Study”, Reports in Water Sector, IIT-Bombay, 2013

Hulya, D., Robertson, S.A., 2008, “Reforming Without Resourcing: The case of Urban Water Supply in

Zambia”, (University of Hertfordshire), International Poverty Center Policy Research Brief, September

2008. (International Poverty Centre is jointly supported by Brazilian Institute for Applied Economic

Research and The Bureau of Development Policy, United Nations Development Program, New York).

IRC,2004, “Economic Instruments for Water Demand Management in an Integrated Water Resources

framework”, Synthesis Report, Environment Canada.

Available:[http://policyresearch.gc.ca/doclib/SR_SD_EconomicInstruments_200502_e.pdf,

http://www.horizons.gc.ca/doclib/SR_SD_EconomicInstruments_200502_e.pdf]. Last accessed : Feb. 29,

2012.

IWR, “Improper Waste Disposal in Bangalore Threatening Water Sources”, 26 May 2011. World Wide

Web Link:[ http://www.indiawaterreview.in/Story/News/improper-waste-disposal-in-bangalore-

threatening-water-sources/211/1#.UhC1ZT4VImw ]. Accessed on 5 July 2013.

Kaur, J., “No Water Shortage, Delhi must use water efficiently”, a Governance One article, 19 June 2012.

World Wide Web Link:[http://www.governancenow.com/news/regular-story/no-water-shortage-delhi-

must-use-water-efficiently]. Accessed on 5 July 2013.

Kakatey, R., Singh, R., K., Chaudhary, A., “Death in Parched Farm Field Reveals Growing India Water

Tragedy”, a Bloomberg report, 21 May 2013. World Wide Web Link:[

http://www.bloomberg.com/news/2013-05-21/death-in-parched-farm-field-reveals-growing-india-water-

tragedy.html]. Accessed on 26 Sept. 2103.

86

Kirmeyer et al., 1994, Kirmeyer, G.J., W. Richards, and C.D. Smith. 1994. An Assessment of Water

Distribution Systems and Associated Research Needs. Denver, CO: AWWA Research Foundation:

Distribution Systems.

Kleiner, Y., and Rajani, B. ~1999!. ‘‘Using limited data to assess future needs.’’ J. American Water Works

Association., 91~7!, 47–61.

Koliyar, J.G., Rokade, N.S., “Water Quality in Powai Lake: Mumbai, Maharashtra”, Proceedings of

Taal2007: The 12th

World Lake Conference: 1655-1659, 2007.

Korteweg, D.J. (1878). “Ueber die Fortpflanzungsgeschwindigkeit des Schalles in elastischen Röhren.”

(“On the velocity of propagation of sound in elastic tubes.”) Annalen der Physik und Chemie, New Series 5,

525-542 (in German).

Krishnan, M., “India faces crippling water crisis”, a DW article, May 29th 2013. Retrieved from World

Wide Link on: 10th July 2013.

Kumar, A., “Against Erratic and unequal Distribution of Water in Delhi”, “Radical Notes”, published on

July 12th 2013, World Wide Web Link: [ http://radicalnotes.com/2012/07/12/against-erratic-and-unequal-

distribution-of-water-in-delhi/ ], Accessed on: 23 July 2013.

Lamont, P.A., “Common pipe flow formulas compared with the theory of roughness”, Journal (American

Water Works Association), Vol. 73, No. 5, Regionalization: Why and How (May 1981), pp. 274-280

Lauchlan C. S., Escarameia M., May R. W. P., Burrows R. and Gahan C. “Air in Pipelines; A Literature

Review.” HR Wallingford, Oxfordshire, Report Sr649, 2005.

Lautenschlager, K., Boon, N., Wang, Y., Egli, T., Hammes, F., “Overnight stagnation of drinking water in

household taps induces microbial growth and changes in community composition”, Water Research, J. Of

International Water Association, Volume 44, Issue 17, pp. 4868-4877.

LeChevallier, M.W., Gullick, R.W., Karim, M., “The Potential for Health Risks from Intrusion of

Contaminants into the Distribution System from Pressure Transients”, Prepared for U.S. Environmental

Protection Agency Office of Ground Water and Drinking Water Standards and Risk Management Division,

2003.

Maas, C., “Greenhouse Gas and Energy Co-Benefits of Water Conservation”. Polis Research Report, 2009,

Madhusudhan, N.R., “BWSSB plans water tariff hike”, A The New Indian Press article, 11 May 2013.

World Wide Web Link:[ http://newindianexpress.com/cities/bangalore/BWSSB-plans-water-tariff-

hike/2013/05/11/article1585092.ece ]. Accessed on 5 July 2013.

87

Madhusudhan, N.R., “Toxic Groundwater threatens lives of Bangaloreans”, An Indian Express report, 27

May 2013. World Wide Web Link:[ http://newindianexpress.com/cities/bangalore/Toxic-groundwater-

threatens-lives-of-Bangaloreans/2013/05/27/article1607801.ece ], Accessed on 3 Aug. 2013.

Mathur, O.P., 2001, “Coming to Grips with Issues of Pricing Urban Water and Intra-City Bus Transport”,

Published in “India: Fiscal Policies to Accelerate Economic Growth”, Conference in New Delhi, May

2001.

Mathur, O.P., Thakur, S., “Urban Water Pricing - Setting the Stage for Reforms”, National Institute of

Public Finance and Policy report, December 2003.

MCD, “Mumbai City Development Plan”, 2005-2025, Municipal Corporation of Greater Mumbai. World

Wide Web Link:

[http://www.mcgm.gov.in/irj/go/km/docs/documents/MCGM%20Department%20List/City%20Engineer/D

eputy%20City%20Engineer%20(Planning%20and%20Design)/City%20Development%20Plan/Urban%20

Basic%20Services.pdf]. Accessed on: 18 June, 2013.

McIntosh, 2003 (August), “Asian Water Supplies: Reaching the Urban Poor”, A Guide and source book for

urban water supplies in Asia for Governments, Utilities, Consultants, Development Agencies and

Nongovernment Organisation by Arthur McIntosh, Published by Asian Development Bank.

McKenzie, R.S., Wegelin, W., 2009, “Implementation of Pressure management in Municipal Water Supply

Systems”, (IWA pres. Paper), 21st February.

Miya-Manila project, 2007, “Urban Water Efficiency”- Miya and Mayniland have joined forces to reduce

NRW (non-revenue water) levels in the western zones of Manila. Available: [http://www.miya-

water.com/our-experience/case-studies/manila]. Last accessed: Jan. 5 2011.

Mohanty et al. 2003, “Mohanty, J. C., Ford, T. E., Harrington, J. J. & Lakshmipathy, V. 2003 A cross-

sectional study of enteric disease risks associated with water quality and sanitation in Hyderabad City. J.

Wat. Suppl.: Res. & Technol. - AQUA 51(5), 239–251.

Nataraj, P., “Groundwater contamination poses a serious threat”, A Deccan Herald report, 29 June 2013.

World Wide Web Link:[ http://www.deccanherald.com/content/341815/groundwater-contamination-poses-

serious-threat.html ]. Accessed on 5 July 2013.

Nelson, K., “Reducing Pathogen Risks In Drinking Water In The Developing World From The Household

To The City Scale”, presented at University of Oklahoma, January 27 2012,

88

NIDM, 2007, National Institute of Disaster Management- Disaster Update, Issue No. 563, January 7th

2007. Available: [http://nidm.gov.in/dupdate_jan_2007.asp]. Last accessed: Feb. 29, 2012.

NRCC (National Research Council Canada), “Water main Breaks data for different materials for 1992 and

1993”, 1993.

NUWA, “13,423 Million Litres Declared As 'Non-Revenue Water', BWSSB Loses Money On Half Of

Water It Supplies”, by Poornima Nataraj, a National Urban Water Awards article. World Wide Web Link:[

http://www.waterawards.in/articles-news/13,423-million-litres-declared-as-non-revenue-water-bwssb-

loses-money-on-half-of-water-it-supplies.php ], 2012. Accessed on 5 July 2013.

PIBS, “India Stats: Million plus cities in India as per Census 2011”, Press Information Bureau,

Government of India. World Wide Web Link:

[http://pibmumbai.gov.in/scripts/detail.asp?releaseId=E2011IS3]. Accessed on 16 Sept. 2013.

PPP Jakarta Water, 2010, “Practical Indonesian PPP”, western Jakarta Water Services, 2010.World Wide

Available:[http://ciriajasa-

mandiri.com/PPP%20Jakarta%20Water%20by%20PALYJA%20April%202010.pdf]. Last accessed: Feb.

29, 2012.

PWD, “Water Infrastructure Management”, Philadelphia Water Department, 2013. World Wide Web ink:

[http://www.phillywatersheds.org/watershed_issues/infrastructure_management]. Accessed on 12 July

2013.

Raghupati, Usha P. and Vivien Foster, 2002, “Water: A Scorecard for India”, Water Tariffs and Subsidies

South Asia: Paper 2, Water and Sanitation Program South Asia.

Ray, A., “Bangalore population booms to 96 lakh”, A Times of India article, 24 May 2103. World Wide

Web Link: [http://articles.timesofindia.indiatimes.com/2013-05-24/bangalore/39501220_1_96-lakh-30-

lakh-population]. Accessed on 16 Sept. 2013.

Ray, I., McKenzie, M., 2009, “Urban Water Supply in India: Status, Reform options and Possible

Lessons”, Water Policy Vol.11, No. 4 pp 442-460, IWA Publishing.

Rogers, D., 2008, “Integrated approach for water network rehabilitation”, Water Asset Management

International, 4.3-September, IWA Publication.

Rusin, P.A., Bose, J.B., Haas, C.N., Gerba, C.P., “Risk Assessment of Opportunistic Bacterial Pathogens in

Distribution Systems”, Reviews of Environmental Contamination and Toxicology, Volume 152, pp. 57-83,

1997.

89

Saini, M., “9596 unmetered water connections found in cyber city”, a Daily Post report, 08 August 2013.

World Wide Web Link:[ http://www.dailypost.in/regions/haryana/1041-9-596-unmetered-water-

connections-found-in-cyber-city ]. Accessed on 11 Aug 2013.

Saini, M., “state proposes to double water, sewage charges”, a The Times of India, 11 Nov. 2010. Accessed

on 5 July 2013.

Saul, 2004, “Water Demand Management- A strategy to Deal With Water Scarcity in Israel- A Case

Study”, Eng. Saul Arlosoroff, Director and chairman of the Finance/Economic committee, The national

water corporation of Israel. Submitted to the IPCRI Conference “Water for Life in the Middle East”, 2nd

Israeli-Palestine-International Conference, Antalya, Turkey 10-14 October 2004.

Senthalir, S., “Water will cost more in Bangalore”, a Times of India article. World Wide Web Link:[

http://articles.timesofindia.indiatimes.com/2011-04-06/bangalore/29388986_1_water-tariff-power-tariff-

bwssb]. Accessed on 26 September 2013.

Sethi, N., “Poison in India’s groundwater posing national health crisis”, A Times of India report, 2 May

2012. World Wide Web Link: [ http://articles.timesofindia.indiatimes.com/2012-05-

02/pollution/31537647_1_groundwater-nitrates-aquifers ]. Accessed on 9 July 2013.

Shamir and Howard, “An Analytical Approach to Scheduling Pipe Replacement”, Journal AWWA, May

1979

Sharma, P., “Water Loss in Mumbai at 50% is highest in Country: Report”, A DNA India Article, 5 Jan

2011. World Wide Web Link: [http://www.dnaindia.com/mumbai/1490423/report-water-loss-in-mumbai-

at-50pct-is-highest-in-country-report]. Accessed on 4 July 2013.

Sharp, W. W., and Walski, T. M. ‘‘Predicting internal roughness in water mains.’’ J. American Water

Works Association., 80(11), 34–40, 1998.

Shilpa, C.B., “Bangalore Development Authority expects to have new sewage treatment plants”, a DNA

India article, 20 May 2011. World Wide We Link:[ http://www.dnaindia.com/bangalore/1545453/report-

bangalore-development-authority-expects-to-have-new-sewage-treatment-plants ]. Accessed on 4 July

2013.

Shivakumar, A.R., “Closing the tap on Bangalore’s leaky water”, a The Alternative article, 10 April 2013.

World Wide Web Link:[ http://thealternative.in/inclusivity/closing-the-tap-on-bangalores-leaky-water/ ].

Accessed on 5 July 2013.

Simon, A. L. and Korom, S. C, 1997. Hydraulics. 4th edition. Upper Saddle River, NJ, Prentice Hall.

90

South African Government Online, Draft-15, 2000, Available:

[http://www.info.gov.za/otherdocs/2000/waterserv.pdf]. Last accessed on 29th February 2012.

Srinath, P., “Right to water bill: Will it increase water supply in Bangalore?” , A Citizens Matter article, 25

July 2013. World Wide Web Link:[ http://bangalore.citizenmatters.in/articles/right-to-water-bill-will-it-

increase-water-supply-in-bangalore/print ]. Accessed on 2 Aug 2013.

Srinivasan, R., “Stealing farmers’ water to quench Chennai’s big thirst”, An Infochange Agenda article,

October 2005. World Wide Web Link:[ http://infochangeindia.org/agenda/the-politics-of-water/stealing-

farmers-water-to-quench-chennais-big-thirst.html ]. Accessed on 5 July 2013.

Srivathsan, A., “Perils of Poor Water Planning in Chennai”, A The Hindu report. 10 June 2013. World

Wide Web Link:[ http://www.thehindu.com/news/cities/chennai/chen-columns/perils-of-poor-water-

planning-in-chennai/article4798067.ece ]. Accessed on 4 July 2013.

SSWM, “Intermittent Water Distribution”, by Florian Faure and M.M.Pandit. World Wide Web Link:

http://www.sswm.info/category/implementation-tools/water-distribution/hardware/water-distribution-

networks/intermittent-w. Accessed on: 27, June 2013.

Sterling, R., Wang, L., Morrison, R., “State of Technology Review Report on Rehabilitation of Wastewater

Collection and Water Distribution Systems”, U.S. Environmental Protection Agency National Risk

Management Research Laboratory, May 2009.

Sudhir, T.S, “Will Bangalore have to be evacuated by 2023”, “Firstpost India” 13th April 2013. World

Wide Web Link: [http://www.firstpost.com/india/will-bangalore-have-to-be-evacuated-by-2023-

697649.html]. Accessed on: 13 May 2013.

TCC, Toronto City Council Water rate Structure 2013. World Wide Web Link:[

http://www.toronto.ca/utilitybill/water_rates.htm]. Accessed on 28 September 2013.

The Hindu, 2010, “The cost of urban water supply”, January 2nd. Available:

[http://www.hindu.com/pp/2010/01/02/stories/2010010250220900.htm]. Last accessed: Aug. 14, 2012.

The Hindu, 2012, “Drinking Water crisis deepens in rural Orissa”, April, 1st. Available:

[http://www.thehindu.com/news/states/other-states/article3268706.ece]. Last accessed: Aug. 14, 2012.

The Hindu, 2013, “Pipe bursts leave city dry”, February 26th.

The Hindu, Business Line, Friday, March 19th,2004. Link:

[http://www.thehindubusinessline.in/2004/03/19/stories/2004031902350500.htm]. Last accessed: June 5,

2011.

91

The Times of India (TOI), “2-year-old dies of suspected water contamination in City”, March 30th 2012.

World Wide Web Link: [http://articles.timesofindia.indiatimes.com/2012-03-

30/bangalore/31260704_1_water-contamination-bwssb-water-pipes]. Accessed on 4 July 2013.

The Times of India, 2010, “Water starved city faces 35% cut after pipe bursts”, March 16th.

Thomas, Sh.(2003). “Air Management in Water Distribution Systems, A New Understanding of Air

Transfer.” Clear Water Legacy, Burlington, Ontario, Canada.

Tijselling, A.S., Anderson, A., “The Joukowsky Equation for Fluids and Solids”, CASA Reports,

Eindhoven University of Technology, 2006.

TOI, 2011, The Times of India article “Chennai Water tankers suck suburbs dry”, May 26th. Available :

[http://articles.timesofindia.indiatimes.com/2011-05-26/chennai/29585323_1_tanker-lorries-private-

tankers-supply-water]. Last accessed: Aug. 14, 2012.

Totsuka, N., Trifunovic, N., Vairavamoorthy, K., “Intermittent Urban Water Supply Under Water Starving

Situations”, 30th WEDC International Conference, Vientiane, Lao PDR, 2004.

TRANSFORM, “Transportation Study of the Region of Mumbai”-Report on Demography, Vol. III,

Population forecasts 2031, LEA International Ltd. Canada and LEA. Associates South Asia Pvt. Ltd. India,

December 2005.

Uitto, J.I., Biswas, A.K., “Water for Urban Areas: challenges and perspectives”, United Nations University

Press, 2000.

Vairavamoorthy, K., Akinpelu, E., Lin, Z., Ali, M.,2001, “Design of Sustainable Water Distribution

Systems in Developing Countries.” London: Water Development Research Unit, South Bank University.

Vairavamoorthy, K., Gorantiwar, Sunil D. and Mohan, S.,2007, “Intermittent Water Supply under Water

Scarcity Situations”, Water International, International Water Resources Association Water International,

Volume 32, Number 1, Pg. 121-132, March 2007.

Vajpai, K.N., “Livelihood links to poor water quality in India: Alternatives”, Water Supply and Sanitation

Collaborative Council, 30 November 2012. World Wide Web

Link:[http://www.wsscc.org/resources/resource-peoples-stories/livelihood-links-poor-water-quality-india-

alternates]. Accessed on 3 July 2013.

Varghese, G., “24-hour water supply, it’s no pipe dream”, Hindustan Times Article, HT Correspondent.

World Wide Web Link: [http://www.hindustantimes.com/news/specials/bombay/Main%20article18.shtml

]. Accessed on 10 Aug. 2013.

92

Walski, T. M., and Pelliccia, A. ~1982!. ‘‘Economic analysis of water main breaks.’’ Journal of American

Water Works Association, 74(3), 140–147.

Water Quality Association, 2005, “Technical Application Bulletin: Copper- Recognised Treatment

Techniques for Meeting Drinking Water Regulations For the Reduction of Copper From Drinking Water

Supplies using Point-of-Use/Point-of-Entry Devices and Systems”.

WSP (Water and Sanitation Program-South Asia), “Benchmarking Urban Water Utilities India”, 2008.