Fitse Gelaye Thesis Submission

P a g e | 1
GREYWATER REUSE FOR HOUSEHOLDS IN
ADDIS ABABA, ETHIOPIA
AN UNDERGRADUATE THESIS SUBMITTED
IN PARTIAL FULFILLMENT FOR THE DEGREE OF BACHELOR OF ARTS
DEPARTMENT OF ARCHITECTURE
COMMITTEE CHAIR
PROFESSOR NAOMI DARLING
COMMITTEE MEMBERS
GABRIEL ARBOLEDA
MICHAEL DAVIS
FITSUM A. GELAYE
MAY, 2015

P a g e | 2
PERMISSION
I give permission for public access to my thesis for any copywriting to be done at
the discretion of the archive’s librarian and/or the college librarian.

P a g e | 3
ABSTRACT
The notion of water scarcity rarely crosses the minds of people in most parts of the
developed world. For some, water is a given, taken for granted because of its abundance.
For others, the only certainty is that they might wake up tomorrow with no access to it.
This is the reality of my hometown Addis Ababa, Ethiopia. The city suffers economic
water scarcity caused by an infrastructure that is unable to meet the demands put on it by
its residents.
Where there is life, there is water use. Where there is water use, there is wastewater
generated. Following this premise, wastewater use, specifically greywater reuse, has been
a promising alternative source of water in areas facing physical water scarcity such as
California and parts of Germany. Through the transfer of this technology, which is
popular in parts of the developed world, to the capital of a developing country, I wanted
to explore the possibility of reusing greywater to help create a supplemental water source
for the residents of Addis Ababa.
Following a comprehensive look into technology transfer, multiple precedent
searches and research conducted on understanding Addis Ababa, I designed and trailed
an easily accessible greywater filter that is cheap, locally made and simple to construct.
The first trial of this product did not succeed, leading to a further exploration of both
materials and approach.
The process of transferring greywater reuse to Addis Ababa is a long and
unpredictable one; however the potential is too great to be given up.

P a g e | 4
ACKNOWLEDGMENT
First and foremost, I would like to thank my advisors Professor Gabriel Arboleda,
Professor Naomi Darling and Professor Davis. Naomi, thank you for pushing me to
achieve what I thought was beyond my abilities. My thesis would be incomplete
without your constant support and encouragement. You are a constant inspiration to me.
Gabriel, thank you for letting me chase my ambitions and inspiring me to keep learning.
Your passion for knowledge is transcendental and has ignited my own. What a beautiful
gift to receive. Professor Michael Davis, thank you for your kindness and support. This
thesis would have been nothing without the funding you helped me acquire and your
constant advice.
Zeweter Gelaye, my soul sister, thank you for always picking up my untimely
calls, be it late nights or early mornings. You are my inspiration! Thank you so much
for pushing me, especially when I could not push myself.
Arch Kids ’15 – Bahia, Garima, Seyrum and Zisisga- I appreciate you so much.
What a group of people to learn with, and learn from! I am blessed to have worked
alongside you. Fiza, Metasebia, Shristi, Barsha Eskedar, Jaleli and Sinafik, my forever
friends! You have been a wonderful support system.
Last but not least, Professor Kate Ballentine and Professor Al Werner, thank you
so much for taking the time to answer my questions and giving me constant support. I
am eternally grateful.

P a g e | 5
TABLE OF CONTENTS
Abstract 3
Acknowledgment 4
List of Figures 7
Introduction 10
Part I: Water: Fresh, Grey and Recycled 14
o Chapter I: Water scarcity 15
- Water Scarcity in the world 16
- Water Scarcity in Addis Ababa, Ethiopia 18
o Chapter II: Greywater 20
- Why Greywater 21
- Limitations to Greywater 21
- Positive Response to Greywater Reuse 23
-
Part II: Adapting the foreign 25
o Chapter III: Transfer of Greywater Reuse Technologies to Addis Ababa 26
- Research Method 27
- Precedent Research 32
- Reflection and Critique on Precedent Research 35
Part III: Alternative Approach 41
o Chapter IV :Analysis of Addis Ababa 42
- Welcome to Addis :An Introduction to the City 42
- Descriptions of the Analytical Maps of Addis 45
- Maps 51
- Criteria for Design 63

P a g e | 6
Part IV: Design, Construction , Trial and Redesign 65
o Chapter V : Precedents from Ethiopia 66
- Greywater Towers in Arba Minch 66
- Keyhole Gardens in Cherenko, Oromia 68
- Reflection 71
o Chapter VI: First Greywater Filter Design 72
- Choosing Materials 72
- Steps of Construction 76
- Construction and Trial of First Design 80
- Experiments for a New Filtering Material 85
- Reflection on the Design Process 89
Part V: Conclusion 92
Appendix I 97
References 98

P a g e | 7
LIST OF FIGURES
1. Figure 1: . Map showing areas that are actively facing water scarcity today
2. Figure 2: Map showing economic water scarcity in the world
3. Figure 3: Map of countries with similar economies as Ethiopia
4. Figure 4: Map of countries with population of over a million people
5. Figure 5: Map of countries with subtropical highland climate
6. Figure 6: Overlaid map showing places with similar climatic, demographic and
economic conditions as Addis Ababa
7. Figure 7: Map showing places with similar climatic, demographic and economic
conditions as Addis Ababa
8. Figure 8: The workings of a Horizontal Flow Constructed Wetland
9. Figure 9: Map 1, sub cities and primary roads of Addis Ababa
10. Figure 10: Map 2, Population Density of Addis Ababa
11. Figure 11: Map 3 Spatial Distribution of Addis Ababa
12. Figure 12: Map 4, Percentage of Durable housing in Addis Ababa
13. Figure 13: Map 5, Percentage of Poor Households in Addis Ababa, Ethiopia
14. Figure 14: Map 6, Location of important services
15. Figure 15: Map 7, Percentage of household with insufficient water supply
16. Figure 16: Map 7, Percentage of household with insufficient sanitation services
17. Figure 15: Map 7, Percentage of household

P a g e | 8
18. Figure 18: Overlay of Map 1, Map 3 and Map 5
19. Figure 19: Overlay of Map 7, Map 8 and Map 9
20. Figure 20: Overlay of Map 2 , Map 4 and Map 6
21. Figure 21: Location of Arba Minch in relation to Addis Ababa
22. Figure 22: Elevation and Section of a Greywater Tower
23. Figure 23: Location of Arba Minch in relation to Addis Ababa
24. Figure 24: Section of a keyhole garden
25. Figure 25: Picture of one of the interviewees attending her key hole garden
26. Figure 26: Comprehensive list of materials
27. Figure 27: Source of Greywater
28. Figure 28: First step of construction
29. Figure 29: Second step of construction
30. Figure 30: Third Step of construction
31. Figure 31: Final Product
32. Figure 32: Photo collage of greywater filtration materials bought in Addis Ababa
33. Figure 33: Photo collage of construction process
34. Figure 34: Final finished product
35. Figure 35: Greywater after it passed through filter
36. Figure 36: Sand bought in Bole Michael neighborhood, Bole Sub City
37. Figure 37. Sand being washed
38. Figure 38: Image of materials used in experiment

P a g e | 9
39. Figure 39: Greywater filtered through one layer of each material
40. Figure 40: Greywater filtered through multiple layers of each material

P a g e | 10
INTRODUCTION
What if the Addis Ababa had an alternative water source?

P a g e | 11
Ever since I can remember, water disruptions have been a constant component
of life in my home town Addis Ababa, Ethiopia. Thus, I grew up with water cuts
limiting the supply of water in my house. On some mornings, I would wake up, open
the tap and find water. On others, I would not. My family and all the citizens of my
city have managed to find ways of shaping their lives around this circumstance. For
some, the solution is as simple as storing water in big water tanks. Others store water
in whatever container they can find in their homes. The most unfortunate walk for
kilometers to buy water and carry it back home.
When I turned 18, I moved to the South Hadley, Massachusetts for college.
Living in the Northeast, I got used to opening the tap and expecting water. The longer
I stayed there, the more distant the water cuts that accompanied my childhood
became. However, when I returned home for break after almost two years of living in
the United States, I was reintroduced to the water scarcity problems of Addis. The
city’s water supply was still unable to meet the demands put upon it, making it
likely that there will always be days when I will wake up, open the tap and find no
water.
But, what if the Addis Ababa had an alternative water source?
What if we, the citizens of Addis, had another option where some of the water
we use comes from a source that is not dependent on the city’s weak water
infrastructure? This is the question that inspired my thesis, which is an
exploration for an alternative water source that is independently controlled by the
people of Addis Ababa.
Where there is life, there is water use. Where there is water use, there is
wastewater generated. If wastewater reuse can be a component of the above given
equation, one can create a constant, additional supply of water that will decrease the
demand for freshwater. This source will also be controlled by the person’s guaranteed
use of water, rather than an incompetent public infrastructure. Based on this premise,

P a g e | 12
I chose to explore greywater reuse as a possible solution for the water scarcity
problems in Addis Ababa. The purpose of this exploration is not to enforce one
solution onto the citizens of Addis. Rather, its intention is to offer a choice that
provides water even when the taps are dry.
Greywater reuse is not a common practice in Addis Ababa, Ethiopia. Thus, this
thesis is also an exploration of the complexities of technology transfer and will
make a commentary on the limitation of design and its implementation on the
ground.
In writing this thesis, I explored a range of sources, from academic journals
written about technology transfer, to scientific papers explaining greywater reuse.
However, the backbone of this thesis is the field work I did in Addis Ababa,
where I conducted independent research on understanding the city and built a
greywater filter based on the information I gathered.
This thesis is divided into five parts. The first part provides an overview of
the water scarcity problems in Addis Ababa and the world as a whole. It also
introduces greywater as a potential solution for this issue. The second part talks more
about international technology transfer and the problems that follow when a design
that proves to be successful in one part of the world is attempted to be implemented in
another. The third part explores an alternative solution, where a design stems out of
the realities of the place it is to be implemented in rather than where its technology
originates from. This section provides an in depth understanding of Addis Ababa, and
concludes by reaching a design criteria for a greywater filter inspired by the
characteristics of the city and local precedents. The fourth part describes the design
and building process of a greywater filter that is based on the aforementioned criteria.
It also discusses the results from the first trial of the resulting product and steps to be
taken in improving it. The final part reflects on the whole process and makes a

P a g e | 13
commentary on the complex task that is technology transfer and how it should be
approached.

P a g e | 14
PART I
Water:
Fresh, Grey and Recycled
Water, is taught by thirst.
- Emily Dickinson

P a g e | 15
CHAPTER I
WATER SCARCITY
I have never been thirsty.
I do not know what it feels to go to bed with my throat dry, or wake early in the
morning to walk kilometers carrying 20 liters of water on my back. I do not know what
it feels like to drink dirty water because it is all I can find. Unlike 1/5th of our world’s
population that lives in areas of water scarcity, all I have to do is walk down the hall
from my dorm room at Mount Holyoke College and open the tap, where clean water is
always guaranteed to flow out.1
This has not always been the case. I am from Addis Ababa, Ethiopia, where I had
grown accustomed to opening the tap and seeing no water flow out. The tap equals
water equation that is a given in most parts of the developed world does not apply in my
house. I just shrug, and reach for a jug to scoop up some water from the full bucket my
mother had already put in the bathroom. When we run out of the water we stored just
in case there was a water cut, my mother will drive or take a taxi to another neighborhood
and fill up two or three of the yellow, 20 liter oil containers that we kept in the house. We
shaped our lives around the inconvenient equation that was a given to us: water cuts will
always happen. Still, I never had to wake up and walk kilometers carrying 20 liters of
water on my back, or consume dirty water.
I am from a city where water is not always guaranteed. This insecurity had made
water a more pronounced factor in my life. However after moving for college to the
United States, I have come close to forgetting what it feels like to open the tap and not
find water. My equation changed from one that was centered on water cuts to the tap
equals water formula of the Northeast. Here, water comes from the faucet and disappears
down the drain, invisible when it is not in my close proximity. The more disconnected I
1
World Health Organization’s fact file - Coping with water scarcity. Challenge of the twenty- first century.
UN-Water, FAO, 2007

P a g e | 16
have become from water, the easier it has become for me to take it for granted. I use
and waste water as if it is an infinite resource, deceived because of its constant
availability.
This could not be any further from the truth!
Figure 1: Map showing areas that are actively facing water scarcity today2
Water Scarcity in the World
Our world’s fresh water supply constitutes 3% of the water on Earth. We cannot
access 2/3rd of it because of its location and the 1% that is currently available to us is
becoming polluted and over exploited. Population growth, urbanization, migration and
industrialization, along with increases in production and consumption, have
2
International Water Management Institute (IWMI). Accessed February 20, 2015.
http://www.iwmi.cgiar.org/.

P a g e | 17
generated an ever increasing demand for freshwater.3
Today, 1.4 billion people live
with water scarcity, and 500 million more are on the fast track to joining them.4 By
2025, it is estimated that 2/3rd
of the world’s population will face water scarcity.5
By 2030,
the world is projected to face a 40% global water deficit if we are to continue with the
business-as-usual climate scenario we are living with today.6
Water is today’s oil and our
blue planet is running out of it fast. This is causing water scarcity problems worldwide.
Water scarcity is an imbalance between the demand and availability of water. It
occurs because of two mechanisms. The first is Physical Water Scarcity, which
materializes because there is a lack of sufficient water resources. The second one,
which this thesis is concerned with is Economic Water Scarcity. It occurs because of the
economic inability to manage available water resources. Economic water scarcity
represents the inequality in the ability to access resources that is so prominent
worldwide.7
About 348 million more people face severe economic water scarcity just
because they lack sufficient infrastructure to access water that they actually have.8
As can
be seen from the following map sourced from the International Water Management
Institute, Sub Saharan Africa is the most severely affected by this issue. Addis Ababa,
Ethiopia, which is the city that this thesis will focus on, is found in this area and faces one
of the most severe water scarcity problems in the developing world.
3 “The United Nations World Water Development Report 2015” Paris: United Nations Educational,
Scientific and Cultural Organization, 2015 pp 12-14
4 “Coping with water scarcity. Challenge of the twenty- first century” World Health Organization’s fact
file - UN-Water, FAO, 2007
5 "Water Scarcity." WorldWildlife.org. Accessed November 2013
http://www.worldwildlife.org/threats/water-scarcity.
6 “Coping with water scarcity. Challenge of the twenty- first century” World Health Organization’s fact
file - UN-Water, FAO, 2007
7 Seckler, David, Randolph Barker, and Upali Amarasinghe. "Water Scarcity In The Twenty- first Century."
International Journal of Water Resources Development: 29-42
8 Seckler, David, Randolph Barker, and Upali Amarasinghe. "Water Scarcity In The Twenty- first Century."
International Journal of Water Resources Development: 29-42

P a g e | 18
Figure 2: Map showing economic water scarcity in the world9
Water Scarcity in Addis Ababa
Addis Ababa, the capital of Ethiopia, is a city where water scarcity is a prevalent
issue. Rapid population growth and poor maintenance, along with a government that
gives priority to industries over households has resulted in making the city’s water
source unreliable and unpredictable.10
In Addis, 40% of the city’s inhabitants use water
from nearby rivers heavily polluted from municipal and industrial wastes.11
In addition to
9
International Water Management Institute (IWMI). Accessed February 20, 2015.
10 Tigabu, T Semu, G, 2008 -Tigabu, Tewodros, and Girma Semu. "Addis Ababa: Urban Profile."United
Nations Human Settlements Programme (UN-HABITAT), 2008. pp6
11
Van Rooijen, D., and G. Gebre. "Urban Water Pollution and Irrigated Vegetable Farming in Addis Ababa."
2009 pp4

P a g e | 19
the part of the population that does not receive direct piped water, inefficient water
management has resulted in severe water cuts even for households that have access to
clean, potable water.
In 2000, the domestic consumption for the whole city averaged around 22
liters/capita/day. The average amount of water used by a person living with in house
plumbing ranged between 80 and 130 liters/capita/day, while a person served by
yard connections, consumed 15- 30 liters/capita/day. Non-domestic use (commercial
and official), amounted to about 25 liters/capita/day. The city’s industries use about 7
liters/capita per day of which about 40% is provided by Addis Ababa Water and Waste
Authority (AAWSA) and the remaining amount is produced by the industries themselves.
Taking into account that water is provided for domestic and commercial use from the
same source, the city’s actual net demand was estimated as 75 liters/capita/day while
consumption was 57 liters/capita/ day.12
There was a great disparity between the demand
for water and what was able to be consumed.
Today, demand for water in Addis is 420,000 cubic meters (420,000,000 liters) per
day, but AAWSA can only supply the city with 270,000 cubic meter (270,000,000 liters)
daily.13 The city has a critical water supply shortage (currently 150,000,000 liters) for both
domestic and commercial use. For every 114 liters demanded by a person, the city only
manages to supply 72 liters, continuing the disparity between water supply and demand.
12
NEDECO “Wastewater Master Plan Volume II” Netherland Engineering Consultants, 2002.
13
Asuelime, Lucky. Selected Themes in African Development Studies: Political Conflict and Stability. 2014 Pp 27- 38

P a g e | 20
CHAPTER II
GREYWATER
As the thirst for water becomes more and more severe, people have begun to seek
alternate sources to ease the incessant demand on freshwater supply. Greywater reuse is
one of such alternatives that is up and coming today.14
Greywater is the wastewater that
is generated from household appliances such as showers, sinks and laundry machines. It
comprises of about 50- 80% of residential wastewater.15
Due to its low content of organic
materials and microorganisms, greywater is easier to reuse for household practices that
do not require potable water such as irrigation, toilet flushing and even laundry.16
Greywater has been put to use for irrigation since the time of ancient Romans,
whom, taking advantage of their rich bathing culture, diverted water from towns to
irrigate areas such as Barbegal in Provence, France. 17
Even after the disintegration of the
Roman Empire, the reuse of greywater continued in most rural parts of the world. For
instance, near Milan, the Cistercians had developed sophisticated washing systems, and
used the greywater from their wash houses to either directly irrigate gardens or feed fish
14
Madungwe and Sakuringwa 2007; Madungwe, Emaculate, and Saniso Sakuringwa. "Greywater
Reuse: A Strategy for Water Demand Management in Harare?" Physics and Chemistry of the Earth, Parts
A/B/C: 2007 231-236.
Tjandraatmadja et al., “A Decision Support Methodology for Integrated Urban Water Management in
Remote Settlements” Water Resour Manage (2012) 27:433–449
15
Al-Jayyousi, O, “Greywater reuse: towards sustainable water management” Desalination I56 (2003) 181 -
192
A/B/C: 2007 231-236
16
Chung, K. and White, M., “Greywater Reuse: Understanding Greywater Reuse Systems in the Current
and Future Urban Contexts and How Individuals can Promote Greywater Reuse” CRP 3840: Green
Cities Cornell University
17
Bracken, P., A. Wachtler, A.r. Panesar, and J. Lange. "The Road Not Taken: How Traditional Excreta
and Greywater Management May Point the Way to a Sustainable Future." Water Science & Technology: Water
Supply: 219.

P a g e | 21
ponds.18
As the world became more urbanized, and piped water systems and sanitation
networks were integrated into society, this tradition was lost.19 However, greywater
reuse is trending again as the water scarcity problems our world is facing has become
more pronounced in recent decades.
In a city like Addis Ababa, where demand for water exceeds its availability,
the positive effects of greywater reuse may present a viable solution. In Addis, most
people dispose of untreated greywater on the ground or into open storm water drains.
This thesis will explore the possibility of reusing greywater (which is considered trash by
the city’s citizens) to potentially ease the problem of water scarcity that Addis faces.
Why Greywater?
Much of the wastewater generated from households’ every day is greywater.
Therefore, the reuse of greywater can supply the citizens of Addis with a
supplemental water source that does not depend on the fragile supply provided by the
city, but rather on their own guaranteed use of water. Greywater reuse also decreases
the release of wastewater into the environment and fully reuses nutrients that might
otherwise have been wasted. In addition, if greywater recycling is done onsite, then less
money will be spent on transporting fresh water from its source to its place of use.20
Limitations of Greywater
The wastewater that comes out of each household is divided into two components.
Blackwater- which is water from toilets- and greywater. The main difference between
18
Bracken, P., A. Wachtler, A.r. Panesar, and J. Lange. "The Road Not Taken: How Traditional Excreta
and Greywater Management May Point the Way to a Sustainable Future." Water Science & Technology: Water
Supply: pp 219.
19
Sheikh, Bahman. "White Paper on Greywater." The American Water Works Association, Water Environment
Federation, and the WateReuse Association, 2013 pp 11
20
Chung, K. and White, M., “Greywater Reuse: Understanding Greywater Reuse Systems in the Current
and Future Urban Contexts and How Individuals can Promote Greywater Reuse” CRP 3840: Green
Cities Cornell University

P a g e | 22
the two is that blackwater contains gross faecal coliform contamination.21
Greywater thus
has less organic matter in it, making it relatively easier to reuse. This, however, does not
mean that it is free of contamination. For instance, Palmquist and Hanaeus identified
low concentrations of 68 of 105 selected hazardous substances while measuring
hazardous materials in greywater generated from Swedish households.22
The main contaminants in greywater include human faecal matter, animal faecal
matter (from pets), hair, skin, fats, grease, detergent, soap, bleach and other materials
discarded in the sink or bath. Depending on the source of the greywater, there can be
some amounts of faecal coliform and other pathogenic organisms.23
Rose et al found
higher faecal coliform levels in shower/ bath water than laundry and sink water.24
Because of this fact, greywater cannot be recycled on a household level for potable use.
In fact, it must be clearly separated from the potable water supply of a household to
avoid contamination and human contact must be minimized as much as possible.
Stored greywater undergoes changes in quality because storing facilitates growth
in the numbers of microorganisms, prohibiting the storage of greywater for more than 48
hours.25
In addition to this, Fewtrell and Key , while conducting a health impact
assessment of greywater reuse in the UK, have identified other possible hazards such as
infection resulting from inappropriate ingestion, chemical intoxication as a result of
exposure to chlorine disinfectant and anxiety resulting from the difficulty of
maintaining a system that may not be running properly. Furthermore, where there is a
21
Emerson, Glenda. "Every Drop Is Precious: Greywater as an Alternative Water Source." Queensland
Parliamentary Library Publication and Resources Unit, 1998.
22
Fewtrell, Lorna, and David Kay, eds. Health Impact Assessment for Sustainable Water
Management. London, UK: IWA Pub., 2008. Pp 89-113
23
Dixon, A. M., D. Butler, and A. Fewkes. "Guidelines for Greywater Re-Use: Health
Issues."Water and Environment Journal, 1999, 322-26.
24
Management. London, UK: IWA Pub., 2008 89-113
25
Dixon, A. M., D. Butler, and A. Fewkes. "Guidelines for Greywater Re-Use: Health
Issues."Water and Environment Journal, 1999, 322-26.

P a g e | 23
communicable disease diagnosed within a household, the infection might spread through
greywater reuse.26
Positive Response to Greywater Reuse
The potential of greywater cannot be denied despite its above listed
limitations. Accordingly, a number of countries such as Germany and United States have
conducted extensive research on the safe reuse of greywater and have created incentives
for its usage through tax reductions and availability of information on reuse.
For instance, according to a 1999 survey of single-family households in southern
Arizona, 13% of the households reused graywater. In today’s projections, this amount is
estimated to be slightly higher because of changes in regulations and the current tax
credit incentives to do plumbing for graywater systems in Arizona. The City of Tucson
promotes a State of Arizona tax credit to graywater users as an incentive to encourage this
practice. In addition, guidelines on how to safely reuse greywater are available both
in Spanish and in English for users, encouraging the incentive to reuse water. 27
California was the first state to establish graywater reuse regulations in 1994.
Because of the drought that it is constantly plagued by, the state has embraced
greywater reuse as a viable method of decreasing freshwater demand. Because of the
lobbying efforts of major greywater activists such as Oasis Design, Greywater
Action, ReWater Systems, Inc and other local stakeholders, the state passed a
law in 2008 that allowed graywater systems using only one fixture—such as a
washing machine—to be put up in households without the requirement of a permit.28
Even though Germany is not facing immediate water scarcity problems, greywater reuse
is flourishing as a method for decreasing water costs. The first official water reuse
26
Management. London, UK: IWA Pub., 2008 89-113
27
28

P a g e | 24
project with greywater started in Berlin in 1989.29
This tradition has continued today. For
instance, one company called Aqua Cycle installs about 20- 60 systems a month for
household use, each filtering an average of 600 liters per day. In addition, countries
like Australia, Japan and South Africa have also benefited tremendously from greywater
reuse technologies and their ability to decrease freshwater consumption and wastewater
release.30
Despite the recognition of greywater reuse as a potential solution to water scarcity
in the above mentioned places, greywater reuse is a foreign concept in Addis Ababa.
Thus, this technology has to be introduced from elsewhere, making the understanding
of technology transfer across borders a mandatory component of this thesis.
29
Nolde E. “Greywater recycling systems in Germany - results, experiences and guidelines” Water Science &
Technology Vol 51 No 10 , 2005, pp 203–210
30
A/B/C: 2007 231-236.
Tjandraatmadja et al., “A Decision Support Methodology for Integrated Urban Water Management in
Remote Settlements” Water Resour Manage (2012) 27:433–449
Emerson, Glenda. "Every Drop Is Precious: Greywater as an Alternative Water Source." Queensland
Parliamentary Library Publication and Resources Unit, 1998. Pp 8-10

P a g e | 25
PART II
Adapting the Foreign
All technology should be assumed guilty until proven innocent.
-David Ross Brower

P a g e | 26
CHAPTER III
TRANSFERRING GREYWATER REUSE TECHNOLOGIS TO
ADDIS ABABA
Even before the term technology transfer came into usage, the transfer of
technological advances from one country to another was common place. With trade
relations between nations spanning centuries, countries from the east and the west
exchanged metalwork, scripture, printing and manufacturing technologies and so
much more to promote economic development.31
However, the term technology
transfer was first coined in in 1945, in a report written for Franklin D. Roosevelt called
“Science, the Endless Frontier” by Vannevar Bush, who was director of the wartime
Office of Scientific Research and Development at the time. Bush’s report advocated for
educational institutions to invent new technologies through government funding for
the benefit of the U.S. economy and the nation as a whole.32
This resulted from the
realization of the role technology played in military advancement during WWII. By the
end of the 20th century, the concept of technology transfer has evolved from military
services to achieve international status. Technology transfer no longer
occurred between industries, a nation’s government and its education institutions and
countries with trade relations alone.33
31
Uchida, O. “Technology Transfer” In The Era of Industrialisation, edited by Shunsaku Nishikawa and
Takeji Abe. Vol. 4 of A History of the Japanese Economy, Iwanami Shoten,1990
32
“ Technology Transfer: The History” Industrial Partnerships Office, accessed December, 2013 https:/ipo.llnl.gov
33
Roffe, P. and Tesfachew, T., “Revisiting the Technology Transfer Debate:Lessons for the New WTO
Working Group”, Accessed December , 2013. http: //www.ictsd.org

P a g e | 27
In a fast paced world where technology driven progress is a constant, economic
growth has become a function of either the ability to innovate new technology or to
adapt what has been invented by others. For countries that do not have the financial
and infrastructural ability to do the first, technology transfer became a viable answer
to breaking the chains of poverty. 34
Hence the transfer of technology from one part
of the world to another in the name of development became a common trend in
international relations.
Research Method
As mentioned above, the transfer of technology across borders to fight
underdevelopment is perceived as a solution against the consequences of poverty. This
handover usually occurs from the developed world to the developing. This North-
South relation brings state-of-the-art technology into developing countries in the hope
that it can quickly narrow the technological and economic gap between the global
north and the global south.35
As the above chapter shows, greywater is considered a
viable solution for minimizing demand on potable water in United States, Australia and
Germany etc. In Addis Ababa, where poverty has resulted in a water infrastructure
that is not up to par, water scarcity is an issue that can potentially be eased by reusing
greywater. All of the aforementioned countries, which have formally recognized the
potential of greywater and created guidelines on how to use it, are parts of the
developed world, calling for the transfer of greywater reuse technologies from countries
in the global north to the capital of a country in the south.36
34
Ingvarsson M., “North- South and South South Technology Transfer- A Conceptual Framework”
UNIDO 2013
35
UNIDO 2013
36
Emerson, Glenda. "Every Drop Is Precious: Greywater as an Alternative Water
Source." Queensland Parliamentary Library Publication and Resources Unit, 1998.

P a g e | 28
Such a form of technology transfer has generally proven to be very challenging, as
coming up with policies that govern the co-operation between the two parts of the
world are highly contested. It’s not just about transferring these technologies, but
also about having them fit into the social, economic and cultural settings of a country.
Consequently, the introduction of a super- technology into a place that might not
have the economic capacity to adapt it and an educated workforce that can maintain
it, has often led to failure . 37
In order to avoid such a failure of integration, it is
essential to find precedents of greywater reuse that can feasibly assimilate into the
lifestyles of Addis’ citizens without causing too much disruption. Such
precedents must thus be:
- Functional in terms of decreasing freshwater demand
- Flexible in terms of scale
- Easy to operate and maintain
Following this criteria, I decide to look into greywater reclamation technologies
available for commercial use worldwide. I chose this path because most companies in
such a business readily provide information on how their technologies work.
Additionally, I have access to customer reviews, which can come in handy for assessing
the success or failure of a product. I came across some that definitely fulfilled the first
criterion I had set, which is to decrease freshwater consumption. For instance, there is
the residential wastewater treatment tanks by Jet Wastewater Treatment Solutions
that break down waste in greywater and claim to treat 500- 1000 gallons (1892 - 3785
liters) of water each day.38
W+W Toilet by Roca Bathroom Solutions merges the
washbasin with the water closet and creates a direct transfer of the greywater from the
Nolde E. “Greywater recycling systems in Germany - results, experiences and guidelines” Water Science &
Technology Vol 51 No 10 , 2005, pp 203–210
37
Shumacher, E. F., “Small is Beautiful” Blond and Briggs, London, 1973 chapter 10
38
Jet Wastewater Treatment Solutions , Accessed October, 2013. http://www.jetincorp.com/

P a g e | 29
sink to the toilet bowl, while simultaneously filtering it to make it adequate for
flushing.39 This certainly does decrease freshwater consumption and does not seem to
require that much labor. For use of irrigation, there is the Laundry to Landscape
Greywater System by Oasis Design. It works by taking the outlet pipe that the
wastewater from the machine comes out of attaching it to a separate pipe that takes the
greywater outside into the garden. Here the pipe is connected to a basin filled with
mulch, which filters greywater and makes it readily available for watering plants. This
claims to be the cheapest and most efficient water reclamation system out there.40
The above examples are just the tip of the iceberg, as there is a large number of
greywater reuse technologies available for commercial use. Despite the large number of
results, this research method was not completely successful. Even though I was finding
smart, efficient technologies, all of them were designed to fit a first world lifestyle and
their ability to be adapted in a third world country was highly limited. The toilet and
the wastewater treatment tanks are too expensive to be applicable in a poor country like
Ethiopia. The laundry to landscape one advocates for the use of sodium free, liquid
soap, that is hard to come by in Addis Ababa. The disparity of circumstances in the two
locations, and the overwhelming amount of products available, made finding a
viable answer to my quest using this method difficult.
Historically, international technology transfer has not just occurred between the
global north and south. It has also taken place within the developing world. This idea
of a south- south technology transfer originated around the time that most African and
Asian countries were freeing themselves from colonialism. Their aim was to break the
dependence on the developed world and empower the third world to take charge of its
own development. This horizontal transfer of technology between countries of similar
39
“W+W Toilet” Roca Bathroom Solutions, Accessed October, 2013
http://www.usa.roca.com/ourproducts/ww
40
“Laundry to Landscape Greywater System,” Oasis Design, Accessed October, 2013.
http://oasisdesign.net/greywater/laundry/

P a g e | 30
economic status did not just allow for solidarity but was also seen a way of putting less
demand on the host.41
Accordingly, finding locations that have similar conditions to Addis Ababa, and
may have greywater reuse projects implemented in them, can make the transfer process
smoother. This calls for physical and economic constraints in locating places to transfer
technology to and from, in addition to the aforementioned criteria. Thus the places
where precedent research should be conducted ought to have similar economy,
population and climatic conditions as Addis Ababa.
Economy
I used economy as a criterion in the search for viable precedent because it limits
material availability, construction costs and also mitigates a class distinction between those
that can afford the greywater reuse systems and those who cannot. It is not logical to consider
such a solution if only a certain number of people can benefit from it.
Led by a federal parliamentary political system for the past 20 years, Ethiopia is a
low income country consistently categorized as one of the poorest in the world.
According to the CIA World Factbook, Ethiopia has a GDP per capita ppp of $1,200
(2012 est.), which is one of the lowest.42
Although Ethiopia has achieved an astounding
93% growth of GDP over the past six years and a wealthy and educated class is
emerging, it has started from a low base, thus, poverty is still a prevalent issue.43
In fact,
about 50% of the population lives under the poverty line. The following map showcases
41
UNIDO 2013
42
Central Intelligence Agency. Accessed October 10, 2014. https://www.cia.gov/library/publications/the-
world-factbook/geos/et.html.
43 Smith, D., “Ethiopia hailed as 'African lion' with fastest creation of millionaires” The Guardian,
December 4, 2013. Accessed December, 2013. http://www.theguardian.com/world/2013/dec/04/ethiopia-
faster-rate-millionaires-michael-buerk

P a g e | 31
countries with GDP per capita ppp between $720 - $2000 placing them in similar
economic situations as Ethiopia.
Figure 3:Map of countries with similar economies as Ethiopia44
Population
I used population as a criterion because it determines the scale in which the
technology is to be applied.
Addis Ababa has a high population density with 3,146,999 people living in an
area of 527 sq km. The following map showcases cities with a population of over 1
million. The following map locates cities worldwide that have population of over a
million.
44
World Share of GDP (PPP) according to data released by the IMF, October 2014

P a g e | 32
Figure 4: Map of cities with population of over a million people 45
Climate
I used climate as a criterion because it also determines materiality.
Addis Ababa is located 9.0300° N, 38.7400° E. The city, due to its high elevation,
has a subtropical highland climate based on the Koppen Climate Classification. Its close
proximity to the equator gives it a constant temperature that averages around 62 degree
F per annum . It has an annual average rainfall of 42.9 inches and the average humidity
is 60%. There are only a few places in the world that have this type of climate while
having similar economic situations and populations as Addis Ababa. This final criterion
thus significantly narrows my field of research to a number of places. The following
map showcases places with subtropical highland and oceanic climate.46
45
http://en.wikipedia.org/wiki/File:2006-megacities-1.png
46
"Climate: Addis Abeba (altitude: 2350m) - Climate graph, Temperature graph, Climate table". Climate-
Data.org. Retrieved 6 February 2015.

P a g e | 33
Figure 5: Map of countries with subtropical highland climate47
Research Results
Overlaying the above given maps allows easy location of feasible places to
conduct precedent research in.
47
http://commons.wikimedia.org/wiki/File:World_Koppen_Map.png

P a g e | 34
Figure 6: Overlaid map showing places with similar climatic, demographic and
economic conditions as Addis Ababa
Figure 7: Map showing places with similar climatic, demographic and economic
conditions as Addis Ababa

P a g e | 35
1) Nairobi, Kenya
Nairobi has a population of 3,138,369. Its average annual temperature is 63.5 degrees
and it gets an average of 42 inches of rain per year . Kenya’s GDP per capita is 1800$.48
2) Harare, Zimbabwe
Harare has a population of 1,606,000. Its average annual temperature is 66 degrees and
it receives 33 inches of rain per year. Zimbabwe’s GDP per capita is 600$.49
3) Antananarivo , Madagascar
Antananarivo has a population of 1, 740, 977. Its average annual temperature is
65.5 degrees and 57 inches of rain per year. Madagascar’s GDP per capita is 1000$.50
4) Katmandu, Nepal
Katmandu has a population of 1, 740, 977. Its average annual temperature is 72 degrees
and 55 inches of rain per year. Nepal’s GDP per capita is 1400$.51
Precedent Research
The above given places are all located in developing countries where the
notion of greywater reuse is not a concept that is popularly embraced. Despite this fact,
there has been encouraging research done in Harare which argues for the possibility
of transferring greywater reuse technologies if the appropriate technology for primary
treatment is available.52
I found one precedent in Kathmandu that utilizes wetlands for
48
Central Intelligence Agency. Accessed October 10, 2014 https://www.cia.gov/library/publications/the-
world-factbook/geos/ke.html
49
world-factbook/geos/zi.html
50
world-factbook/geos/np.html
51
world-factbook/geos/ma.html
52
Madungwe and Sakuringwa 2007; Madungwe, Emaculate, and Saniso Sakuringwa.
"Greywater Reuse: A Strategy for Water Demand Management in Harare?" Physics and Chemistry of the
Earth, Parts A/B/C: 2007 1231-236

P a g e | 36
reclamation of greywater.53
There were no precedents available in Nairobi but a I found
second precedent in Nakurur, Kenya where a school is effectively using greywater for
irrigation.54
There was no information available on greywater reuse in Antananarivo.
Both of the precedents found through this research utilized Horizontal Flow
Constructed Wetland Systems. This is a system that is designed to mimic the natural
filtration process found in natural wetland ecosystems.55 These systems use wetland
plants and soils as a filter for cleaning wastewater. The following illustration shows
how a typical Horizontal Flow Constructed Wetland works.
Figure 8: The workings of a Horizontal Flow Constructed Wetland
53
Shrestha RR et al., “Application of constructed wetlands for wastewater treatment in Nepal”, Water,
Science and Technology 44 (2011) :381-6
54
Muchiri, E. Raude, J. Mutua, B. “Urine Division Dehydration toilets and greywater treatment at Secondary
School, Nakuru, Kenya” (2011). accessed November 25, 2013, http://press- susana.org/ lang-en/case-studies pp 2-5
55

P a g e | 37
Dr Roshan Raj Shrestha’s family House, Kathmandu, Nepal (1998)
Dr. Shrestha’s house is the first house in Kathmandu that treats and recycles its
wastewater to reduce water consumption and water pollution. Dr Shrestha, who
pioneered the use of wetland systems for wastewater treatment in Nepal, proved
that it is possible to decrease water consumption through the reuse of greywater
at a household level. The system employed here consists of a 0.5 cubic meter water
tank that has been converted into a settlement tank followed by a feeding tank and a
small vertical flow reed bed with an area of 6 sq. meter. The system is good enough to
treat all the greywater generated by the household, which consists of seven members,
allowing them to save 400 liters per day. The system was able to remove an average of
97% of all pollutants. Though this is a very promising project conducted at a scale that
is small enough to be relevant for this thesis, the cost of it was high (500$). The size of
the wetland system was also too large, taking up an amount of space that is not
necessarily available in a crowded city as Addis Ababa.56
Crater View Secondary School, Nakuru , Kenya (2008)
Aimed at demonstrating that greywater can effectively be reused for irrigation
purposes, ROSA (Resource Oriented Sanitation concepts for pre-urban areas in Africa),
in association with the European Union and the Nakurur Municipality conducted a pilot
project in Crater View Secondary School, Nakuru , Kenya. The part of the town
the project was conducted in had little to no connection to a sewer line. Thus,
greywater from dishwashing and the kitchen was disposed of in the open, creating an
area that was grossly contaminated by wastewater.57
The project provided a greywater
treatment system that reuses greywater generated from preparing food and washing
dishes at Crater View secondary school. The system also receives water from hand
56
57

P a g e | 38
washing basins in the kitchen area. The process of filtration was achieved by a gravity
flow, single pass treatment of greywater through a pre-treatment followed by a
horizontal sub-surface flow constructed wetland (HSSF CW). The wetland uses vetiver
grass (Chrysopogon Zizanioides L) as a filtering element and maintains the filtered
water surface at 15-30 cm below the ground level. The greywater treatment system
consists of a collection trough (dish washing facility), a settlement tank of 250 litres and
greywater collection tank of 750 litres, where the recycled greywater is collected.
Intensive awareness creation and demonstration workshops were carried out to educate
the students and teachers on the management of the system, which the school is in
charge of.58
This system requires space and is relatively capital intensive (cost was estimated
at 1433 euros). In addition, in a monitoring report done three years after the
completion of the project, it was seen that the recycled water generated was insufficient
to fulfill the demand that was placed on it. It was also difficult to judge the reactions
that the school children and teachers had to the introduction of this foreign system.
Reflection and Critique on Precedent Research
The Horizontal Flow Constructed Wetland system that aforementioned
precedents used was a very large . The one used in Dr. Shrestha’s house took up 6 meter
sq. and the one in Carter View secondary school is likely to be bigger. This makes the
scale of the system too large to be adopted for households in Addis. Additionally, Dr.
Shrestha’s’ unit cost 500 dollars (which translates as 10,000 birr) and the project in
Kenya cost 1433 euros (which translates to 32,945 birr). It is very unlikely that a single
household in Addis will be able to afford such expensive systems, making its
introduction an impossible task.
58

P a g e | 39
Moreover, there is a decisive flow in this method of research I used in reaching
this point. The information that was provided on the aforementioned projects was very
limited. The information on Dr. Shrestha's house did not include details on the type of
plant used in the system, its maintenance and the necessary labor input. The
information provided by the NGO that conducted the project at the Carter View
secondary school was one sided. It was not possible to find information on the reaction
of the users of the technology. This gap in information creates a fractured image of the
projects, which undoubtedly interferes with their assimilation of the technologies in
Addis. Making an accurate assessment of these projects will be a failed task if the voices
of the those central to these projects- the people using these technologies - is not heard.
Had the other criteria been met by these projects, I could have done further research to
fill this information gap. Yet, it, coupled with the other limitations made this task an
unnecessary one.
In order to avoid a mishap in transferring technology, one has to go to the places
in which these technologies originated from and make assessments of their viability.
This should be done by physically assessing how they work and directly questioning
the people that are using them. Still, going through such a time and money consuming
process does not guarantee that what worked in these places will ultimately work in
others, be it in Addis Ababa or anywhere else in the world. Such an assumption will
lead to essentializing the people in the two places and assuming that they share the
same norms, which is rarely the case. Even if a technology may decrease labor input in
Kathmandu, it may double the labor burden in Addis Ababa. A technology that can be
scaled up to reach a large number of people in Kenya may be confined to a certain
demographic in Addis Ababa, limiting the success of technology transfer. Technology
thus might end up being a burden on the people it is to benefit, instead of making their
lives easier.

P a g e | 40
This calls for an alternative approach. In this process, an analysis of local
conditions coupled with opinions of local people will be the starting point of the
research for determining what technology is applicable and what is not. In the case of
this thesis, this means doing an in depth analysis of Addis Ababa: the city, the people
and the water and sanitation infrastructure, and following this trail to find the answer.
Such an analysis will be discussed in the following chapters

P a g e | 41
PART III
Alternative Approach:
Analysis of Addis Ababa, Ethiopia
In 1887, Empress Taytu Betul was admiring the landscape at the foot of the Entoto Mountain,
when she saw a flower of rare beauty. Enchanted by the nice climate, she asked her spouse,
Emperor Menelik II, to build her a house where the flower grew. That one house gave birth to a
whole city, which Taytu named “Addis Ababa”
(New Flowe)

P a g e | 42
CHAPTER IV
AN ANALYSIS OF ADDIS ABABA
Welcome to Addis!
The nighttime ride out of the Bole International Airport and into the heart of
Addis Ababa is deceiving. I did not think of it so, the night I arrived back home to
begin researching the possibility of greywater reuse in the city. Seated in the back of
my mother’s car, with my luggage safely tucked in the trunk, I peeked out of the side
window and was greeted by the numerous cars honking and trying to maneuver their
way through the bustling traffic inching down Africa boulevard. Glancing at the
sides of the road, I saw it lined with glass curtained buildings, marked by bold signs
that advertise the cafes, boutiques, cinemas, gaming stations and tattoo parlors they
harbor inside them. The sharply dressed people strolling on the well-lit sidewalks, the
numerous cars moving past my mother’s rugged Toyota, the street lights that bounce
off the windows of buildings and made them shimmer, they all created the
impression of a city that has lept out of poverty to an era of fast development.
Mimicking the name that she received from her founder, Addis Ababa has
flourished to become the capital of not just Ethiopia but the whole of Africa. Nestled
in the valley between Mount Wochocho and Mount Entoto, Addis is still spreading
her petals, engulfing land from its neighboring regions to make room for the
nearly 3.4 million people who call her home. Countering her horizontal
expansion, Addis Ababa is also growing vertically, stretching as if to surpass the
height of the mountains that surround her. New opportunities that encourage
business ventures has made Ethiopia the second highest producer of millionaires in
Africa (Smith, 2013). One can see these new found riches expressed in the construction
boom that has taken over Addis. Yet, as the economically stable portion of Addis
changes, the rest of the city is left behind. With every vertical stretch the city makes,

P a g e | 43
the people in her low income communities are propelled out to the peripheries,
displaced to make room for things ‘bigger and better’ than they are.
Nevertheless, despite the recent presence of multiple story buildings and their
bold English signs lining her streets, small, informal settlements made of rusted
corrugated zinc, crumbling rammed earth and sheets of plastic are still a part of the
city’s fabric. In the light of day, it is clear to see such old, shanty settlements live side
by side with the shiny and new. The well-dressed people on the sidewalk,
representing the thriving part of the city’s population, are shadowed by small, barely
dressed kids begging for a few cents. The abundant cars cruising down Africa Avenue
are paralleled by men driving herds of cattle and donkeys on the sidewalks. And the
lights, well, they always fall victim to incessant power cuts.
Addis has always been a city of polar opposites, where diversity and
disparity have managed to live as peaceful neighbors. Addis used to possess the
ability to harbor the old and the new, the millionaires and the poor, those with
education and those without, the animals and the cars together in near perfect
harmony. Yet today, as she strides towards achieving growth that is profoundly
inspired by the west, her harmonious existence rests on progressively shaky ground.
There is an obvious tension between modernity and memory. Her aim for the first is
detaching her from her roots and gradually elevating her to the levels of the
development she seeks. Simultaneously, Addis’ rich history pulls down at her in an
attempt to keep her grounded in her traditions. Addis is thus caught at a pivotal
moment of choice between adopting the new, salvaging the old or finding a middle
ground between the two starkly different options.

P a g e | 44
The tension between modernity and memory that has gripped Addis Ababa
gives more weight to the consequences of adopting a foreign technology such as
greywater reuse. In order to make a technology assimilate into a city that is trying to
make out her identity, there needs to be a compromise between what is existing and
what is external. An attempt of directly transferring a foreign technology from one
place to another without reaching such a compromise can prove detrimental, as
no two places have the exact same local conditions. Thus, based on principles of
Intermediate Technology and Ethnoengineering, which advocate for starting
from the local, I decided to let Addis guide my greywater filter design.59
Such a
method results in a product that comes from the city rather than one that is
implemented from outside, giving integration a better chance.
This chapter chronicles the analysis I conducted of Addis Ababa, from the
economic to the demographic, to the infrastructural, in an attempt to gain a better
understanding of the city’s local makeup. Addis is a diverse city whose complexity
can be hard to conceptualize. Thus I decided to boil down the information that I
gathered and represent it using maps. In this manner of representation, it will then be
easy to visually understand the numerous characters of the city. I overlapped the
maps, and used the layered information to determine overarching criteria for my
design that is conditioned by the reality of the city.
59
Arboleda, G. “Ethnoengineering: Negotiating the Modern in a ‘Culturally Appropriate’ Government
Program in Ecuador.” Ph.D. diss., University of California, Berkeley, 2012
Shumacher, E. F., “Small is Beautiful” Blond and Briggs, London, 1973 chapter 10 -11

P a g e | 45
Descriptions of the Analytical Maps of Addis
Addis Ababa is run through three layers of government; the city government
on top, sub cities in the middle and kebeles at the bottom. A sub city carries out
municipal functions within its physical boundaries following the principles of the
city’s government and is further divided into Kebeles. Addis has ten sub cities
(reference figure 9) and over 203 kebeles.60
Map 1 showcases the boundaries of these
sub cities and the primary roads that connect them. Most of the primary roads are
concentrated around the northern part of the city, where Addis’ civic center is located
(reference figure 9). These roads are interconnected and lack a defined pattern,
showing the organic growth of the city over the course of the past century. Addis has
spread out from the north and is gradually stretching further south. At the moment,
there is only one strip of highway that connects the southern sub city, Akaki/ Kaliti,
with the northern part. Looking at this map begins to give a clue as to which parts of
the city are more active, and which are less vibrant.
Map 2 showcases the population distribution of Addis (reference figure 10).
According to the national consensus taken in 2007, Addis had a population of
2,687,593 people. Today, this number is projected to be just under 3.4 million.
Harboring all these people in a land of 527 sq kms has made Addis a densely
populated metropolitan region. Addis’ population, aside from those affected by
homelessness, currently lives in 628,986 housing units. 61
As can be seen in Map 2, and
adding to the active sites hinted at by Map 1, much of the density of the city is
centered around Addis’ civic center. The four sub cities in the innermost part of town -
Arada, Addis Ketema, Lideta and Kirkos- are severely overcrowded, with population
densities that range from 25,560 people per sq kms to 13, 591 people per sq kms.
Simultaneously, the sub cities in the peripheries- Bole, Akaki/ Kaliti and Yeka-
60
“Urban Inequalities Report : Addis Ababa” Cities and Citizens Series, UN Habitat, 2004 pp7
61
Addis Ababa; Atlas of Key Demographic and Socio Economic Indicators” Population Affairs
Coordination Sub process Finance and Economic Development Bureau, Addis Ababa, 2010

P a g e | 46
currently have significantly more room to spare , with 1437 people per sq. km living
in the least crowded areas.
Map 3 Showcases the urban density of the city, distinguishing which parts are
more built upon and which are still open (reference figure 11). Currently, out of
Addis’ 527 kms sq area the 290 sq kms is has a built up. 62
The built up area follows
the population density and the provision of roads, with more people inhabiting the
more central parts of the city than its edges. The forest coverage of Addis, which has
now been reduced down to 3%, is concentrated in Gullele sub city. Akaki/Kaliti, the
easternmost parts of Bole and some sections of Yeka sub city have a lot of open space
to spare while the innermost sub cities are densely constructed. In Addis Ketema ,
there are an average of 6,609 housing units per square kilometer. Arada has 4,755
housing units/ sq.km , Lideta has 4,032 housing units per / sq. km and Kirkos has
3,756.63
About 80% of Addis Ababa is characterized as slums, as even the areas with
newly constructed and modern buildings have shabby housing located adjacent to
them.64
Map 4 shows the concentration of durable housing in each sub city
(reference figure 12). Dense, poor quality housing is a commonality in Addis and even
the sub cities with the better quality of houses like Bole, Kolfe Keranio and Arada
have almost half their housing units listed as non-durable. In fact, each sub city has
almost three times more slum households than non-slums ones.65
One reason for this
is that most of the low income houses in Addis were built by feudal lords before the
reign of Emperor Haile Selassie came to an end in1974.66
( These houses are currently
62
Tolon, Uni ” Comparison of Urban Upgrading Projects on Development Cooperation in Ethiopia”
2008
63
Federal Democratic Republic of Ethiopia population Census Commission. Summary and Statistical Report of
the 2007 Population and Housing Census, December 2008 Addis Ababa.P 25
64
Tigabu, T Semu, G, 2008 -Tigabu, Tewodros, and Girma Semu. "Addis Ababa: Urban Profile."United
Nations Human Settlements Programme (UN-HABITAT), 2008. Pp 12
65
“Urban Inequalities Report : Addis Ababa” Cities and Citizens Series, UN Habitat, 2004 – 13 pp 12
66
Nations Human Settlements Programme (UN-HABITAT), 2008.

P a g e | 47
owned by the city government and are rented out to the city’s residents. However,
the city administration does not conduct proper maintenance on these aging houses,
and the people inhabiting them lack the means to maintain the houses themselves.
Thus, they are currently crumbling to pieces. Another reason for the low quality of
housing in the city is the material that is used in their construction.67
Three quarters
of the city’s houses are informally made from mud and wallet walls, which require
constant maintenance, which they are not currently receiving. The issue of
maintenance is hence a big reason for the low quality of housing in Addis.
Map 5 showcases economic distribution in the city (reference figure 13). Almost
all of Addis has sections that are engulfed with poverty. Even the rich neighborhoods
have destitute settlements surrounding them. The boundary between the poor,
middle class and rich areas of the city is thus quite blurred, as all of them exist
together, their houses bleeding into one another. The darker patches on the map show
the most destitute of households. They are found all over the city, even in the most
affluent sub city; Bole. However, some areas do have a greater concentration of poor
households than others. As can be seen from Map 5, Akaki/Kaliti, Nifas Silk and
Addis Ketema have a greater concentration of poverty. However, even in the other
sub cities, despite whatever affluence they may have, 68-80% of their households are
considered poor.68
Map 6 shows the location of water sources and disposal in Addis Ababa
(see figure 14). Addis gets her water from three main reservoirs; Geferssa, Legedadi
and Dire. Legedadi reservoir is located 33 kms north east of the city and supplies
Addis with 150,000 cubic meter of water everyday. Dire reservoir, located 30 kms
north east of the city, supplies Addis with 43,000 cubic meters of water while
Geferssa reservoir, located 18kms north west from Addis, provides another 25,000
67
Nations Human Settlements Programme (UN-HABITAT), 2008.pp 8-12
68
“Urban Inequalities Report : Addis Ababa” Cities and Citizens Series, UN Habitat, 2004 p12

P a g e | 48
cubic meter/ day. An additional 10, 000 cubic meter of water comes from natural
springs scattered all over the city and about 30,000 cubic meters comes from a number
of wells located in the Akaki/ Kaliti sub city.69
Map 6 also shows the location of the
only wastewater treatment plant in the city. The plant, which is called Kaliti
Wastewater Treatment plant, has the capacity to treat 7,600 cubic meters of
wastewater per day. Only three percent of the city population (960,000 people)
are connected to the sewer line that brings waste water to the plant , which is located
in Akaki/ Kaliti sub city. 40% of the population (1,366,000 people) has houses that
are connected to septic tanks.70
These tanks are pumped by government subsidized
vacuum trucks when full.The pumped sludge is disposed of in dry beds in the Kaliti
Wastewater Treatment Plant or in a sludge treatment plant in Kotebe. The rest of the
population has insufficient sanitation services, and thus dumps out wastewater onto
the streets of Addis or into the Akaki river, which flows across the city.71
Map 6 additionally shows the location of Merkato, which is the largest open
market in Africa and supplies most of Addis’ commercial needs. It shows where Bole
International Airport - the main gateway into the country- is located. And finally, Map
6 locates Repi Landfill, the city’s only solid waste disposal site.
Map 7 represents the insufficiency of water available in the city (See figure 17).
As mentioned in previous chapters, there is a disparity between the water supply of
the city and the demands put forth by Addis’ residents. Water cuts are hence a
common thread in the lives of all of Addis Ababa’s residents, even for those with
private connections. They occur because of the high volume of wastage due to faulty
and unmaintained piping, ( as high as 35%), priority given to industries over
households, and lack of improved facilities that can keep up with the city’s rapid
population growth. Most households in the slums of Addis do not have easy access to
69
NEDECO “Wastewater Master Plan Volume II” Netherland Engineering Consultants, 2002. Pp4-5
70
NEDECO “Wastewater Master Plan Volume II” Netherland Engineering Consultants, 2002. Pp4-5
71
NEDECO “Wastewater Master Plan Volume II” Netherland Engineering Consultants, 2002. P 4-5

P a g e | 49
clean water. For instance, 34% of Addis gets their water from public tabs that are
constantly interrupted.72 As can be seen from Map 7, even in the sub cities that are
considered to have better access to water like Bole, Yeka , Kirkos and Lideta, 30% of
the households lack access to clean water. Sub cities like Akaki/ Kaliti, Arada and
Gulele have 60- 80% of their households facing insufficient water access.73
Map 8 shows the lack of sufficient sanitation services available in Addis
Ababa ( See figure 18). 26% of Addis’ population does not have access to any toilet
facilities and thus use open spaces, rivers and ditches for sanitation services.74
In
Addis, dug pit latrines that can be emptied are by far the most common toilet
facilities (68.3%) while 7.3% of the householdsuse the traditional pit latrine (not
emptied). Only 4% of the households have flush toilets, while 10% use non-flush
toilets that are connected to the sewer system. 33% of households share one toilet
facility with more than six other families. As can be seen from Map 8, even in sub
cities like Bole, Nifas Silk and Kolfe Keranio, which have a higher number of in house
sanitation services available for their residents, about 53- 75% of their households still
lack proper toilet facilities. The situation is even more dire in the central part of the
city, (Arada, Kirkos, Lideta) where 85- 90 percent of the population does not
have adequate toilet facilities available for them.75
In addition to the above information that is gathered from multiple
international and national sources, it was also important to hear the voices of the
people of Addis. In order to do so, I passed around a questionnaire that asked the
following questions;
1) On average, how often do you get water cuts per week?
72
Nations Human Settlements Programme (UN-HABITAT), 2008.pp 19
73
Urban Inequalities Report : Addis Ababa” Cities and Citizens Series, UN Habitat, 2004 pp 14-17
74
Nations Human Settlements Programme (UN-HABITAT), 2008. Pp9 -10
75
Urban Inequalities Report : Addis Ababa” Cities and Citizens Series, UN Habitat, 2004 pp19- 21

P a g e | 50
2) Do you have any alternate methods of accessing water – aside from the piped
line? i.e—rainwater harvesting, well, stream, river
3) Do you have a garden? If so, how many times per week do you water it?
4) Do you reuse the greywater you produce daily or do you get rid of it. How?
5) If you don’t reuse the greywater you produce, would you consider reusing it?
6) If yes, how much labor and money are you willing to put into reusing
greywater? (On a scale of 100-500 birr)
(See appendix 1 for full questionnaire)
These questionnaires were given to family heads (usually mothers) who
oversee the running of the house. Out of the many questionnaires I spread, I received
35 responses. The responses showed that the 35 households get an average of 3-4
water cuts per week. 14 of the households had gardens. Four households listed down
bottled water as an alternative source, while the remaining 31 did not have an
alternate method of accessing water. Three households said that they reuse greywater
that is not too dirty to clean their house’s compound, while the rest said that they get
rid of all used water. 15 of the households said that all their wastewater goes into the
septic tank or sewer system. The remaining 20 identified that the water from the
kitchen and from laundry (which are parts of the house that are usually not connected
to the septic tanks) is dumped out on to the streets or into storm drains. 10 of the
responses were in favor of reusing greywater as long as it did not cost more than 130
birr of 6.5 dollars. Map 9 shows the physical location of these 10 households ( see
figure 17).

P a g e | 51
Maps
Figure 9: Map 1, Sub cities and primary roads of Addis Ababa76
76
Coordination Sub process Finance and Economic Development Bureau, Addis Ababa, 2010.
"Google Maps." Google Maps. Accessed February 9, 2015. http://maps.google.com/.

P a g e | 52
Figure 10: Map 2, Population Density of Addis Ababa77
77
Coordination Sub process Finance and Economic Development Bureau, Addis Ababa, 2010.

P a g e | 53
Figure 11: Map 3 Spatial Distribution of Addis Ababa78
78
Urban Inequalities Report : Addis Ababa” Cities and Citizens Series, UN Habitat, 2004
Tolon, Uni ” Comparison of Urban Upgrading Projects on Development Cooperation in Ethiopia” 2008

P a g e | 54
Figure 12: Map 4, Percentage of Durable housing in Addis Ababa79
79

P a g e | 55
Figure 13: Map 5, Percentage of Poor Households in Addis Ababa, Ethiopia80
80

P a g e | 56
Figure 14: Map 6, Location of important services 81
81
NEDECO “Wastewater Master Plan Volume II” Netherland Engineering Consultants, 2002.

P a g e | 57
Figure 15: Map 7, Percentage of household with insufficient water supply82
82

P a g e | 58
Figure 16: Map 8, Percentage of household with insufficient sanitation services83
83

P a g e | 59
Figure 17: Map 9, Location of people willing to reuse greywater84
84

P a g e | 60
Figure 18: Overlay of Map 1, Map 3 and Map 5

P a g e | 61
Figure 19: Overlay of Map 7, Map 8 and Map 9

P a g e | 62
Figure 20: Overlay of Map 2 , Map 4 and Map

P a g e | 63
Criteria for Design
By overlapping the maps that I made to represent the information I gathered, it
was clear to me that there cannot be one universal design that will answer the
question of water scarcity for all the households in Addis. Addis is just too large and
diverse a city. However, I learned that the parts of the city that are more active and
more densely built up are the ones that have higher rates of poverty (see figure18)
.These areas are overcrowded and have housing units that are in fragile conditions
(see figure 19). These same areas also have the poor water and sanitation services (see
figure 20). Thus, based on this information I came up with a set of criteria for the
design of my greywater filter that responds to the physical and economic needs
of these overcrowded, low income and underserved areas.
The first criterion is that the greywater filter has to be cheap and easily
constructible. This decision is based on the poor economic situation of most of Addis’
residents. If the product can be made with minimal expense and with little knowledge
of construction skills, it can be accessed by a lot of people.
The second criterion is that it has to be made of locally accessible materials.
This criteria is supplemental to the first one and allows anyone who chooses to
make this product have easy access to the materials needed for its construction
The third criterion is that the product has to be structurally independent (portable).
This is because most of the housing that is available in Addis is structurally weak
and does not need another burden to carry. In addition, the city is undergoing a
construction boom that is displacing most of the low income communities that live in
the central sub cities. If the greywater filter is portable, anyone who owns it will be
able to take it along with them if they are forced to leave their homes.

P a g e | 64
The final criterion is that the greywater filter is spatially efficient. This is
because the large population density of the city, prohibits the availability of space for
a physically large product.
In addition, based on the information that I received from the questionnaire
that I spread, decided to filter mainly greywater that comes from washing dishes
and doing laundry. My reason for choosing to do so is that the greywater from the
two activities is easily accessible, as it is usually the one disposed of into the streets
or storm drains rather than going into the plumbing system of most households.
Rather than spending money to divert the greywater that comes from showers and
sinks and usually ends up in the septic tank, the greywater from kitchens and laundry
can be accessed for free. Furthermore, the greywater from the kitchens and laundry, is
usually the water that ends up polluting the city, thus reusing it has the added benefit
of a cleaner city. What’s more, not all households have the same way of disposing of
greywater. As stated earlier in this chapter, about 60% of the households in the city
are not connected to a septic tank or the sewer line. In this case, any available
greywater can be filtered.

P a g e | 65
PART IV
Design, Construction, Trial and Redesign
To the first steps,
the small actions,
the failures
and most importantly, to the learning moments

P a g e | 66
CHAPTER V
PRECEDENTS FROM ETHIOPIA
Following the research I did to understand the makings of Addis Ababa and the
criteria I set up, I began the search for precedents again. Simultaneously doing a
worldwide search, like I did in the beginning of my project, had proven insufficient in
gathering adequate information. This time, however, I decided to begin looking for
projects in Ethiopia and was lucky enough to find two.
Greywater Towers in Arba Minch
Figure 21: Location of Arba Minch in relation to Addis Ababa
A greywater tower is a circular bag which contains a mixture of soil, ash and
compost with a gravel column at the center. Leafy plants or vegetables are planted in
holes cut in the side of the bag itself and each day the available greywater from a
household is poured directly on the gravel column. A pilot of this project was conducted
in Arba Minch, a small town 436km southwest of Addis Ababa. This project began in
2007 and was a collaboration between the Arba Minch municipality, the Arba Minch
University and an Austrian NGO called ROSA (Resource Oriented Sanitation
concepts for peri-urban areas in Africa). The materials that are used in constructing these
towers are: a bucket without a bottom, five poles 2m in height, a 1m x 2.5m shade cloth,

P a g e | 67
0.05 cubic meter soil, 0.2 cubic meter compost, 0.14 cubic meter ash and 0.085 cubic meter
gravel.85
The first step of the construction is to mark out a circle with a radius of 40 cm using
a nail and a thread. The bottom layer of the tower is dug out and the side poles firmly
planted. Next, the shade cloth is wrapped around the poles. Following this, the bucket is
placed inside the cloth cylinder and filled with gravel. The soil mixture (3 parts soil, 2
parts compost and 1 part ash) is then backfilled around the bucket. The bucket is
partially pulled out, leaving the grave in position and the sides are backfilled with
more o f t h e soil mixture. This procedure is repeated until a 1m level is reached.
Following this, leafy plants such as lettuce, kale and spinach are planted onto the sides of
the tower, in slits made to the cloth.86
The result should look like the following image.
Figure 22: Elevation and Section of a Greywater Tower
85
Shewa, W and Geleta, B, “Greywater tower for peri-urban areas Arba Minch, Ethiopia” 2010, accessed
November 25, 2013, http://press- susana.org/ lang-en/case-studies. Pp2
86
Shewa, W and Geleta, B, “Greywater tower for peri-urban areas Arba Minch, Ethiopia” 2010, accessed
November 25, 2013, http://press- susana.org/ lang-en/case-studies. pp2-3

P a g e | 68
The construction of this unit did not require skilled labor, can be done in a short
time, and the maintenance is easy. The materials used are also inexpensive. However, in
an email correspondence with the heads of the project, I was informed that the project is
no longer in action. I was not given any specific reason for why the project was
discontinued when I asked. Yet, it is noted in their project brochure that the cloth that is
wrapped around the poles and gives the tower its form only lasts for one year before
rotting. The fact that people have to remake the towers every year could be a
contributing factor as to why there was not a permanent uptake of the product.
Keyhole Gardens in Cherenko, Oromia
Figure 23: Location of Cherenko in relation to Addis Ababa
A Keyhole Garden is a raised (waist height) garden bed surrounded by rocks and
stones. The bed is comprised of layers of various organic materials that add nutrients
while retaining moisture, thereby making the keyhole gardens productive even in arid
areas. It is designed to be watered with greywater, which can be applied to a gravel
filled basket at the center, thereby watering the layer beneath. The basket is woven of
reeds or thatch grass, which, along with the gravel, helps filter out some of the chemicals
from soap and detergents. This method is actively applied in rural towns in the

P a g e | 69
southern and eastern regions of Ethiopia, especially around the Cherenko region in
Oromiya, by Catholic Relief Services (CRS), an American NGO.87
Figure 24: Section of a keyhole garden (graphics provided by CRS)
I was able to make a trip to Cherenko and see some functioning keyhole gardens in
action. CRS had taught farmers who lived in the area how to construct these gardens.
There were many of them lining the highway that connects Addis Ababa to another major
city called Dire Dawa, which is located in the east of the country. I managed to talk to ten
homeowners who had these keyhole gardens. I was informed from my interviews that the
gardens are maintained very easily, requiring an average of two hours per week. One
woman specifically said that “ All I have to do is pour the dirty water (greywater) into
the gravel column and clean up any weeds that may be growing on the garden bed”. The
homeowners stated that the construction of these units did not require skilled labor, but
took up a couple of days to complete. Everyone I interviewed insisted that the keyhole
87
Bakker, E and Boelee, E “Greywater reuse interventions: keyhole and vertical gardens: Case studies of
multiple use of water in Ethiopia” International Water and Sanitation Center ,2010 pp3-6

P a g e | 70
gardens functioned adequately and the vegetables they grew in them have been beneficial
in improving the nutrition of their family members.
Figure 25: Picture of one of the interviewees attending her key hole garden
Though this was an inspiring project, adapting it to the urban setting of Addis
Ababa was problematic. The materials that are used to make these keyhole gardens
(mainly the rocks for the border and the manure in the soil mix) are materials local to the
rural parts of the country and that cannot be easily found in the city. In addition, a single
unit takes up about two meters, which is space that is hardly available in an overcrowded
city like Addis Ababa. Another problem, quite similar to the Greywater Towers, is that the
filtered water only ended up for irrigation use, and did not extend to anything more.
While in this context, water for irrigation is valuable, in the city there is less need for it.

P a g e | 71
Reflection
The discovery of the two precedents of greywater reuse in Ethiopia was very
encouraging. Despite the fact that both of them cannot be directly implemented in Addis,
the concept that they used of filtering water through gravel is a solution with potential.
The greywater is filtered when it passes through the gravel column under the action of
gravity and its impurities are captured in the gaps between the gravel stones. The
smaller the gap is, the more filtered the water gets. Additionally, the more gravel is
present for the greywater to pass through, the cleaner the water that is filtered. This
makes using a material with small grains, such as sand, a solution worth exploring.

P a g e | 72
CHAPTER VI
FIRST GREYWATER FILTER DESIGN
Choosing Materials
Following my precedent findings in Southern and Eastern Ethiopia, I chose sand as
the filtration material for my design. Sand has small particles and even smaller gaps
between them. This characteristic makes it a great material for filtering water, as it
captures more impurities in the small spaces between its particles. Sand was first used
to filter water for private, potable use in 1804 Scotland. By the late 1800’s, sand filtration
had become more commercial and was integrated into the public water supply of cities
like London and Altona. Today, slow sand filters are put to use in many places
worldwide like Amsterdam, London and Paris.88
In addition to this large scale use of sand as a filter to clean raw water, it is also
used to filter greywater. A simple sand filter can have different layers of sand: from fine
grained, to coarse and then to gravel. Passing greywater through such layers adequately
traps the impurities in it, resulting in water that is clean enough that it can be used for
household needs that do not require potable water.89
In chapter IV, I laid down a set of criteria for designing a greywater filter fit for
households in Addis . These criteria are:
1. The greywater filter has to be cheap and easily constructible
2. It has to be made up of locally accessible materials
3. The product has to be structurally independent (portable)
4. The greywater filter is spatially efficient
88 Huisman, L. and Wood, W.E. ”Slow Sand Filtration” World Health Organization, 1974 pp15
89
"REUK.co.uk - The Renewable Energy Website." Sand Filters for Greywater. Accessed November 4, 2014.
http://www.reuk.co.uk/Sand-Filters-for-Greywater.htm.

P a g e | 73
Choosing sand as the filtration material works well with criteria one and two. A
sand filter can be made at home by anyone with limited skills. All that is required is
multiple types of sand to be poured into a container through an open top and an exit
hole for the filtered water to escape out of. Because the small gaps in between sand
particles trap the impurities in water, it will get dirty from time to time, requiring some
form of maintenance. The filter can be maintained by scraping off the top layer and
either washing it or replacing it with clean sand. Addis is a city that is eternally under
construction. This construction boom has resulted in the availability of sand in almost all
neighborhoods of the city, making it a material that can easily be accessed. Its simplicity
of use and its consistent availability in Addis thus makes sand an optimum filtering
material for greywater reuse in the city.
While conducting research on sand as a filter, I also discovered that charcoal has
the ability to attract an-ions such as nitrates and phosphates that are found in
greywater, and is used in composting bins to absorb the odor of mold. I also wanted to
use gravel so that the sand does not block the exit of the filtered water from the container.
Using burlap as a way to separate the layers of sand, charcoal and gravel so that they
don’t get too mixed is another decision I made. Burlap has tiny gaps between its threads
that will allow water to pass through, but block sand, charcoal and gravel, helping to
maintain their layering. I also decided to use burlap as the first filter layer which will
trap bigger impurities like hair and food scraps. This helps the other filter layers stay
relatively cleaner and also makes cleaning the filter easier as the user can easily wipe of
the filtered residue from the burlap.
After choosing the layering of sand, charcoal, gravel and burlap as my filtration
method, I need a container to place them in. The more filtering materials that greywater
has to pass through, the more it gets filtered. Thus there needs to be space in the container
large enough to hold a thick layer of sand, charcoal and gravel. In addition, there needs to
be some space available for the greywater to rest when being filtered. This requires a
sizable container.

P a g e | 74
In Addis, because of the constant fear of water cuts, people store water in their
homes. It is very common for them to use oil containers for this purpose. These oil
containers are also commonly used for transporting water from one neighborhood to
another, when one runs out of stored water in the house. Small restaurant owners in
the city cut out holes near the bottom of these oil containers, plug in a faucet, fill them
up with water and use them as a makeshift tap for their patrons. Using these bright
yellow oil containers as part of the design is thus a sensible choice because they are
already a familiar object constantly put to use in the society. These containers have the
capacity to hold 20 liters, providing enough space for the filtering materials and some
short term storage for the greywater during filtration. This container is cheap, easily
accessible, has sufficient room, can stand on its own and is spatially efficient (measuring
2 feet high, half a foot long and a foot wide). It thus passes all of my criteria.
The fact that the materials I am going to use are cheap and easily available is not
sufficient enough for the greywater filter to fulfill my design criteria. The tools that are
used in the making of the product also have to be easily accessed by anyone. In order to
make this greywater filter using the materials I already have, I need to cut off the top of
the oil container to create a big enough opening for pouring the sand, gravel and charcoal
in. I also need to create an exit point somewhere on the container for the filtered water to
escape out of and place a faucet there to control its rate of flow. I chose to use a kitchen
knife for making the needed incisions on the oil container, as it is available in any
household. However, it would take a lot of force to use a kitchen knife to make long cuts
on the container. Instead, heating up the blade of the knife and using the warm metal to
melt the plastic of the container becomes an efficient solution.

P a g e | 75
Figure 26: Comprehensive list of materials

P a g e | 76
As I have stated before in Chapter IV, the greywater that is going to be filtered is to
be sourced from the kitchen and laundry of a household. This means the sand filter that I
am designing is going to filter grease, food scraps, soap, potential fabric pieces and hair.
The filtered water is then going to be reused for non-potable use such as cleaning and
flushing toilets, watering gardens, cleaning the house and compound or cleaning cars.
The reused water will thus not be used for direct consumption, but will be used for
activities that will lessen the demand for drinkable water.
Figure 27: Source of greywater
Steps of Construction
The first step in constructing the grewyater filter is to warm the knife and use it to cut off
the top of the plastic oil container. This creates a container that has an open top, allowing
one toeasily place the filtering materials inside( Reference Figure 28) .

P a g e | 77
Figure 28: First Step of construction
The next step is to heat up the knife more and pierce a hole in the container an inch
above the bottom. After making a small hole with the kitchen knife, heat up the faucet
and force it into the hole. (Reference Figure 29 and Figure 30). Wrapping the end of the
knife and the front end of the faucet in cloth when heating them up is advisable to avoid
getting burnt.
Figure 29: Second step of construction

P a g e | 78
Figure 30: Second step of construction
Following this, pour in the gravel until it covers the top of the faucet hole. Then
add a layer of burlap, then add the charcoal, another layer of burlap and finally add the
sand which will occupy about 1 ft of the vertical space in the oil container (Reference
figure 31). This arrangement creates a layered system in which greywtaer is dumped
into the top of the oil container and filtered as it passes through the different layers of
material.

P a g e | 79
Figure 31: Third Step of construction

P a g e | 80
The final touch is to tie some burlap around the top opening of the oil container to create
a first layer to filter big impurities such as food scraps and hair. (Reference figure 32)
Figure 32: Final product
Construction and Trial of First Design
After coming up with the final design while in South Hadley, MA, I went back to
Addis Ababa to construct a trial product and assess its maintenance. I found the materials
that I needed as expected. Sand was being sold all over the city in small shops that sold
construction materials. It cost 70 – 80 birr / 100 kg (3.50 – 4 $/ 100 kg) 10. Gravel was also
being sold at these shops for 60 birr/ kg (3$/100kg). Charcoal is sold in small kiosks and in
street markets for an average of 10 birr (0.5 $) per bag . A bag is sufficient for the
greywater filter I am designing. I found plastic burlap sacks as the cheapest available
form of burlap. One sack has the capacity to carry 100kgs and when cut apart, is large
enough to make one greywater filter following the aforementioned design. Most
households in Addis already have the yellow oil containers. In the off chance that the oil

P a g e | 81
containers are not available in someone’s house, they can be bought for about 50
birr (2.50 dollars) in Merkato: Addis’ open market.
Figure 33: Photo collage of greywater filtration materials bought in Addis Ababa
(burlap, gravel, sand and charcoal)

P a g e | 82
Figure 34: Photo collage of construction process
Following the aforementioned steps of construction, I was able to make the design filter in
two hours. Piercing the oil container to fit in the faucet took the longest time (45 minutes).
This is because I had to be careful not to make a hole that was larger than the spout of the

P a g e | 83
faucet. It was helpful to have an extra hand holding the oil container in place while I
pierced the hole in.
Figure 35: Final finished product
Unfortunately, the filter I built failed to work. Rather than filtering the water, the
greywater I poured into it came out muddy. (Reference figure 36.)

P a g e | 84
Figure 36: greywater after it passed through the greywater filter
The reason behind the failure of the greywater filter is that the sand available in the
city, which is construction sand, was too dirty. It had different sizes of particles that
prevented it from trapping the impurities in the greywater or its own dirt particles.
(Reference figure 37)
Figure 37: Sand bought in Bole Michael neighborhood, Bole Sub City

P a g e | 85
I remade the greywater filter multiple times using sand found in three other
neighborhoods (Kasanchis in Bole Sub City, Merkato in Arada Sub City and Urael in Bole
Sub City.) The results were the same. I attempted to wash the sand before using it
(Reference Figure 38). The sand required too much water to clean, defeating the whole
purpose of designing a filter that saved water.
Figure 38. sand being washed
Experiments for a New Filtering Material
As discussed in the above chapter, sand filters greywater by trapping its impurities
in the tiny gaps between its particles. Following the first failure, I wanted to see if I could
substitute sand with another material that uses the same concept of trapping impurities to
clean water. Thus, I restarted the precedent search yet again.
A group of students from Olin College of Engineering in Needham, MA conducted
an experiment on the effectiveness of using different types of fabric to filter water. The
aim of their project was to clean the turbidity from pond water for non- potable use
in Kenya. They experimented with a multitude of fabrics, from polyester to cotton to silk
and discovered that the latter was able to filter water effectively. They published their

P a g e | 86
results in an instructable that concluded that a woven fabric whose weft and warp are the
same size, has the ability to filter water by trapping impurities in the gaps between its
threads.90
In another research project conducted on water sourced from a pond in Dean Park,
Shrewsbury MA, researchers discovered that passing turbid water through eight layers of
burlap, as compared to silk, cotton and polyester, was effective in decreasing turbidity.91
Microbiologists from the University of Maryland used saris as a way to filter river water
for households in rural Bangladesh. The found out that saris made of cotton folded four
times reduce the cholera content in river water by 99 percent. 92
Students at Cornell
University are currently designing a water filter that can clean water for potable use.93
Following these precedents, I did multiple experiments where I attempted to
filter greywater through layers of silk, cotton, burlap and one inch thick cushion foam
(Reference figure 39). None of the aforementioned precedents used greywater as the
water for filtration, making my experiments mandatory. I conducted these experiments
in South Hadley, MA and used greywater from hand washing my laundry and doing my
dishes. The type of detergent I used in South Hadley and the amount of spices and grease
in the left overs I washed from my dishes made the quality of the greywater that is
produced different from the greywater sourced out of homes in Addis Ababa.
Additionally, storing greywater is a health hazard. Thus the quality of greywater that I
used varied from experiment to experiment, as I had to use a different batch of greywater
each time I conducted one. However, the quality of the greywater used within each
experiment was the same. The materials I used were bought locally in South Hadley
and surrounding areas.
90
"Water Filtration Using Fabric." Instructables.com. Accessed March 9, 2015.
91
Tammisetti, R “Research on the Effectiveness of Using Cloth as a Filter to Remove Turbidity from Water”
2010 p 10
92
Colwell, R. R. "Reduction of Cholera in Bangladeshi Villages by Simple
Filtration."Proceedings of the National Academy of Sciences: 1051-055, 2002
93
Chu, K et al, “Foam Filtration, Fall 2014 Final Report” Cornell University 2014)Accessed March 5, 2015.
https://confluence.cornell.edu/display/AGUACLARA/FoamFiltration.

P a g e | 87
Figure 39: Image of materials used in experiment
I filtered greywater through multiple layers of each material (Reference Figure 40
and 41). I used the change in the turbidity of the greywater as proof of filtration.

P a g e | 88
Figure 40: Greywater filtered through one layer of each material
Figure 41: Greywater filtered through multiple layers of each material

P a g e | 89
Silk, which cost 25$/ yard, filtered greywater the best. The water that came out was
significantly cleaner, but it took 20 minutes to filter just 50mls of greywater. In addition, it
was too expensive. Cotton and burlap did not make that much of a significant change in
the turbidity of the greywater, even when layered. Foam, on the other hand, showed a lot
of potential. Not only does it trap impurities, especially grease, but it also traps soap
residue well. Foam is available in Addis Ababa for a reasonable price (a 2” by 4” block
is sold for four birr (0.25 cents) in kiosks city wide. This makes it a material that has
potential to fulfil my design criteria and work as a filtering element in the redesign of
a new greywater filter.
Reflection on the Design Process
As greywater reuse is not currently practiced in Addis, this choice to explore its
potential meant introducing the notion of greywater filtration into a society that is not
necessarily familiar with it. I am currently based in South Hadley MA but designing a
product for Addis Ababa, Ethiopia.Thus, for this thesis project, not only was I going to
introduce the idea of greywater reuse from the outside to Addis, but I also had to do a
majority of the task from outside of Addis. The inquiry that followed inspired the
collision of two different worlds, sparking a back and forth across 6,794 miles and
between two different realities; one where access to water is a given and another where
water scarcity is certain.
While caught in between this back and forth, I designed a greywater filter in
South Hadley based on a set of criteria I determined from studying Addis Ababa
and built my designed product in Addis. This product, i.e. the sand filter, failed to
function properly when put to the trial. Sand is a great filtering material on the books.
Despite this fact, the quality of sand available in Addis was too low for it to filter any
impurities, cancelling out sand filtration as a possible solution.

P a g e | 90
The failed trial brought to my attention the potential disparity between what works
in my studio and what can function on ground in Addis. The 6,794 miles between these
two places made my design one step removed from the reality of Addis, as the materials
that I can access in South Hadley are different versions of the materials available back
home. This means, every design I come up with will be based on the assumption that the
materials I use in the greywater filtration experiments I conduct in my studio are of
similar quality to materials available in Addis. Because of local factors, I cannot with
certainty say that a design that has potential to work in South Hadley will also work in
Addis. Filtering greywater through layers of foam, which I stated as having tremendous
potential to work, thus has the same chance of succeeding or failing as the sand filter.
Because of this lack of assurance, each design I come up with will have to be tested in
Addis Ababa.
The reverse of this problem, the fact that some materials that are available in
Addis Ababa aren’t available in South Hadley , is also another issue with designing from
afar. For instance, while I was experimenting on fabrics and foam, I was unable to find the
20 liter oil canteens that I had decided to use as a container in Addis Ababa. Thus, I had
to substitute another container, whose size and shape were not exactly compatible with
the oil canteens found in Addis. This fractured the design process, so that if I decide to go
back and trial foam as a filtering material, I have to readjust how I place it into the oil
containers, adding another layer of uncertainty. This takes away from the amount of time
that I have to try the product, monitor its progress and make any needed corrections to it.
If I run out of time, I would have to return to South Hadley and begin the design process
again, which will mandate me to go back to Addis for another trial run, creating an
expensive, time consuming and exhausting cycle.
Oscillating back and forth between the two different places is very inefficient,
and makes the process of design a “hit or miss” one. However, this does not mean that
greywater reuse has to be abandoned. Thus, a solution that I propose is to narrow the

P a g e | 91
distance between the studio where the design is being proposed and the city its
implementation is to occur in. I make this suggestion because the more local the
experiments, the more local the materials used and thus the more efficient the design
process will be. The ideal solution is thus to design in Addis, for Addis. This provides
the opportunity to use actual materials that are available in the city during the whole
design process, ensuring that the design of the filtration system can go hand in hand
with the overall design of the product itself. A shorter range between design and
implementation allows for enough time to construct the product and do an adequate trial
of it. This also gives one the time to monitor the product, understand what type of
maintenance it will need and how frequent maintenance should be done. It also narrows
the distance between the designer and the users that are potentially going to use the
product, making it easier to form a relationship that could guarantee the continued
improvement of the product.

P a g e | 92
PART V
Conclusion
A distraught king noticed a little black ant as it struggled to carry a grain up a slope on a wall.
The wall was wet and slippery and the first attempt of the ant was a failure. The grain slipped from
its hold and fell on the ground. Undaunted, the ant retraced its steps, picked up the grain and
started again on the arduous journey up the slippery wall. The grain slipped and fell once more.
The process repeated itself seven times. Each time, the ant started its uphill task afresh, not
discouraged by the failures of the past. The seventh time, it found its footing and successfully
carried the grain on to its destination.
-A King Learns from an Ant

P a g e | 93
The purpose of technology has always been to lighten the burden of work man has
to carry out in order to stay alive and develop his potential.94 However, ever since
technology was brought down to human scale in the early 20th century and made
available to help ease the day to day life of the west, the question of how it is to be
assimilated into society has been a contested one. This has resulted in a spectrum of
responses. On the one hand there are those who believe that the availability of technology
should help society break its usual habits, denounce its history, condemn its traditions
and redefine itself. A technologically enhanced age is a new age, where previous
culture is to be reformed and people are to adjust their pace to that of technological
advancement.95
On the other hand, there is the belief that caution should be taken when
dealing with the changes that technology will inevitably bring. The compromise of
culture, history and there by the identity of a society, in the rush to adapt the more
efficient life technology promises, may lead to an inhuman existence.96
Thus, those at this
end of the spectrum believe in taming technology so that it can fit existing molds of
society.
In the case of technology transfer, especially when it is tasked with alleviating
poverty, the aforementioned spectrum is as visible as ever. Its presence leads to questions
such as, how should technology be incepted to fully function in a new place? Should it be
transferred as is, or adapted to the cultural setting it is to be placed in? Is there a formula
for its correct implementation? During this thesis project, I have progressively travelled
from one end of the spectrum to the other, which has given me perspective on the above
mentioned questions.
I began my quest for finding a greywater reuse technology that can be transferred
to Addis Ababa by attempting direct technology transfer. The vertical transfer of a
product originating in the global north to a city in the global south was not
successful. This is because there was a big difference between the two places that
94
Shumacher, E. F., “Small is Beautiful” Blond and Briggs, London, 1973 Chapter 10
95
Banham, R. “Theory and Design in the First Machine Age”, 1960
96
Shumacher, E. F., “Small is Beautiful” Blond and Briggs, London, 1973 Chapter 10

P a g e | 94
made the integration of the technologies I found though my research an impossible task in
Addis . This misstep made me realize that doing a worldwide search for precedents
was not the right path to take. Consequently, I decided to find locations that had
similar local conditions as Addis Ababa and narrow down my area of research. I found
cities with demographic, climatic and economic conditions that resembled that of Addis’
and restarted my search for precedents. This horizontal approach resulted in me locating
two greywater reuse projects, one in Kenya and one in Nepal. However, the two
precedents were, again, not applicable in Addis because their implementation was still too
expensive for the average household in Addis Ababa to afford. Additionally, the
information provided was so limited that I was unable to know the maintenance
requirements of the products, their labor input and more importantly, the reaction of the
users.
I realized that copying a greywater filtration technology from one place, dragging it
across boundaries and pasting it in Addis, be it from the developed world or a developing
country, could lead to a technology too foreign to assimilate. This called for yet another
change in my approach, in which I design a product that is shaped by the character of its
new home, to give greywater reuse a better chance of integration into Addis’ local
lifestyle. I decided to have the design for the greywater reuse technology be based
on a set of limitations determined by Addis herself. In this approach, I decided to go to
Addis, understand the makings of the city, listen to what people are doing regarding their
water use, learn about the city’s water source and disposal and let all of this determine a
design criteria for the product that should be used. Accordingly, I conducted research to
find yet another set of precedents that are compatible to this criteria and adapted their
design to fit Addis Ababa. This attempt, though taking me one step closer to finding the
solution, also failed. This happened because there was a distance between the design
process and its implementation (between South Hadley, MA where my studio is in and
Addis Ababa) that needed to be narrowed.

P a g e | 95
This called for yet another change in my approach. My ideal next step will be to
go back to Addis and design and build a greywater filter there. During the course of this
project, I had the opportunity to pitch my idea of reusing greywater in Addis Ababa at a
conference organized by The Clinton Global Initiative University. This opportunity has
put me in contact with organizations that are interested in funding such projects. Using
possible funding resources like these, I would like to provide information on
construction, usage, and maintenance of the product for residents of Addis Ababa. This
information will ideally be communicated through “how to” graphics, and will be
available in public spaces such as the main offices in kebeles (Addis’ smallest
administrative units ). This allows the people of the city to be easily exposed to this
information, as they have to go to their nearby kebele office’s to pay bills and for
community gatherings. The aim is that anyone who chooses to can quickly build an
inexpensive greywater filter for their homes, and create a supplemental source of water
for themselves.
As can be seen from the above detailed process I took, technology transfer is a
complex task. There is no set formula for it and it will not succeed if it follows a one
dimensional plan. Instead, it has to be a process that constantly adapts itself to the
circumstances of its place of implementation. I began this thesis with a question, a single
“what if…” that sought to find a potential solution for the water scarcity problems in my
home town. I will not conclude it with an answer, as the process of my design is not yet
complete. Rather, I will end for now with yet another question mark:
Will a greywater reuse product that is designed and built locally provide an alternative source of
water for Addis?

P a g e | 96
I would also like to end by emphasizing the value of water. It takes two gallons of
water to brush our teeth, 10- 25 gallons for the five minute shower we take. Five gallons
to flush a low-flow toilet, 23 gallons to produce the slice of bread and cheese we have for
breakfast, 37 gallons for the coffee beans in our cup. It takes a whopping 660 gallons of
water to produce a hamburger, 12 gallons to clean the dishes , 27 gallons to wash our
clothes and 25 gallons to produce the electricity we use to browse on our computer for 5-
10 hours. Water is an integral part of each moment of our daily life. It is what our
existence depends on. 97
What if tomorrow, you opened your tab and found no water?
Soon enough, this might actually to be a possibility for anyone, living in any part of
the world, be it poor or rich. Water scarcity is not just a thing that happens to the poor
anymore. Even for those living in the safety of the Northeast, it's ever stretching grip is
getting closer and closer. Today, it's not just the developed world reading about poor
villagers in rural Ethiopia who have to walk for kilometers just to access water, but it's my
mother in Addis opening the news and hearing the scarcity issues that California is facing.
Water scarcity is no longer the problem of people living in the deserts or in poverty. It is
everyone's. Thus we need to recognize the value of water and change the wasteful way in
which we use it.
Just because water is used it does not mean it is wasted. It just means that it is
dirty. All that is needed is to clean it and use it again, just like one would a shirt or a plate.
Greywater reuse thus should be seen as a possible solution not just for Addis Ababa, but
also for the rest of the world that has not considered it as an option.
97
"EPA WaterSense | Water Education & Our Water Cycle | Water Use Today." EPA. Accessed May 5, 2015.

P a g e | 97
Appendix I
Questionnaire on Greywater Recycling and Reuse for Households in Addis Ababa,
Ethiopia
Primary Investigator: Fitsum Gelaye
Location:
Number of people living in the house: Housing Type:
English Version:
1) On average, how often do you get water cuts per week?
2) Do you have any alternate methods of accessing water – aside from the piped
line?i.e—rainwater harvesting, well, stream, river
3) Do you have a garden? If so, how many times per week do you water it?
4) Do you reuse the greywater you produce daily or do you get rid of it. How?
5) If you don’t reuse the greywater you produce, would you consider reusing it?
6) If yes, how much labor and money are you willing to put into reusing
greywater? (On a scale of 100-500 birr)
Amharic Version:
1) ውሀ:በሳምንት:ስንት:ቀን:ይጠፉል?
2) ከቧንቧ:ውሀ:የተለየ:የውሀ:ምንጭ:አሎት?
3) ግቢዎ: ውስጥ: የኣትክልት: ቦታ: ኣሎት? መልሶ: ኣዎ :ከሆነ: በሳምንት :ስንት: ጊዜ: ዉሃ: ያጠጡታል?
4) የፍሳሽ:ዉሀውን: ድግመው :ይጠቀሙታል? እንዴት? ድግመው : የማይተቀሙት: ከሆነ: እንዴት:ያስወግዱታል?
5) የፍሳሽ:ዉሀውን: ደግሞ:መጠቀም:ላይ: ያሎት: ሀሳብ: ምንድን: ነው ?
6) መልሶ :ኣዎ :ከሆነ :ገንዘብ :አና :ጉልበት :ለማውጣት :ፍቃደኛ :ኖት?

P a g e | 98
References
• Addis Ababa; Atlas of Key Demographic and Socio Economic Indicators”
Population Affairs Coordination Sub process Finance and Economic Development
Bureau, Addis Ababa, 2010.
• Addisababa.gov.et Accessed November, 2014 . http://www.addisababa.gov.et/.
• Al-Jayyousi, O., “Greywater reuse: towards sustainable water management”
Desalination I56 (2003) 18 l-l 92
• Arboleda, G. “Ethnoengineering: Negotiating the Modern in a ‘Culturally
Appropriate’ Government Program in Ecuador.” Ph.D. diss., University of California,
Berkeley, 2012 2012
• Asuelime, Lucky. Selected Themes in African Development Studies: Political
Conflict and Stability. 2014 Pp 27- 38
• Bakker, E and Boelee, E “Greywater reuse interventions: keyhole and vertical
gardens: Case studies of multiple use of water in Ethiopia” International Water and
Sanitation Center ,2010
• Bracken, P., A. Wachtler, A.r. Panesar, and J. Lange. "The Road Not Taken:
How Traditional Excreta and Greywater Management May Point the Way to a
Sustainable Future." Water Science & Technology: Water Supply: 219.
• Bush, V. 1945 endless frontere gabe p - Bush, Vannevar. Science, the Endless
Frontier A Report to the President. Washington: U.S. Govt. Print. Off., 1945.
• Chu, K et al, “Foam Filtration, Fall 2014 Final Report” Cornell University
2014)Accessed March 5, 2015.
https://confluence.cornell.edu/display/AGUACLARA/FoamFiltration.
• Chung, K. and White, M., “Greywater Reuse: Understanding Greywater Reuse
Systems in the Current and Future Urban Contexts and How Individuals can
Promote Greywater Reuse” CRP 3840: Green Cities Cornell University

P a g e | 99
• Colwell, R. R. "Reduction of Cholera in Bangladeshi Villages by Simple
Filtration."Proceedings of the National Academy of Sciences: 1051-055, 2002
• Dixon, A. M., D. Butler, and A. Fewkes. "Guidelines for Greywater Re-Use:
Health Issues."Water and Environment Journal, 1999, 322-26.
• Emerson, Glenda. "Every Drop Is Precious: Greywater as an Alternative
Water Source." Queensland Parliamentary Library Publication and Resources
Unit,1998.
• "EPA WaterSense | Water Education & Our Water Cycle | Water Use Today." EPA.
Accessed May 5, 2015.
 Federal Democratic Republic of Ethiopia population Census Commission.
Summary and Statistical Report of the 2007 Population and Housing Census,
December 2008 Addis Ababa.P 25
• Fewtrell, Lorna, and David Kay, eds. Health Impact Assessment for Sustainable
Water Management. London, UK: IWA Pub., 2008.
 Huisman, L. and Wood, W.E. ”Slow Sand Filtration” World Health Organization,
1974
• Ingvarsson M., “North- South and South South Technology Transfer- A
Conceptual Framework” UNIDO 2013
• International Water Management Institute- International Water
Management Institute (IWMI). Accessed February 20, 2015.
• Madungwe and Sakuringwa 2007; Madungwe, Emaculate, and
Saniso Sakuringwa. "Greywater Reuse: A Strategy for Water Demand
Management in Harare?" Physics and Chemistry of the Earth, Parts A/B/C: 2007
1231-236.

P a g e | 100
 Muchiri, E. Raude, J. Mutua, B. “Urine Division Dehydration toilets and
greywater treatment at Secondary School, Nakuru, Kenya” (2011). accessed
November 25, 2013, http://press- susana.org/ lang-en/case-studies
• NEDECO “Wastewater Master Plan Volume II” Netherland Engineering Consultants,
2002.
• Nolde E. “Greywater recycling systems in Germany - results, experiences and
guidelines” Water Science & Technology Vol 51 No 10 , 2005, pp 203–210
• "REUK.co.uk - The Renewable Energy Website." Sand Filters for Greywater.
Accessed November 4, 2014. http://www.reuk.co.uk/Sand-Filters-for-Greywater.htm.
• Roffe, P. and Tesfachew, T., “Revisiting the Technology Transfer Debate:Lessons
for the New WTO Working Group”, Accessed December , 2013. http: //www.ictsd.org
• Seckler, David, Randolph Barker, and Upali Amarasinghe. "Water Scarcity In
The Twenty- first Century." International Journal of Water Resources Development: 29-42
• Sheikh, Bahman. "White Paper on Greywater." The American Water Works
Association, Water Environment Federation, and the WateReuse Association, 2013
• Shewa, W and Geleta, B, “Greywater tower for peri-urban areas Arba Minch,
Ethiopia” 2010, accessed November 25, 2013, http://press- susana.org/ lang-en/case-
studies.
• Smith, D., “Ethiopia hailed as 'African lion' with fastest creation of
millionaires” The Guardian, December 4, 2013. Accessed December, 2013.
http://www.theguardian.com/world/2013/dec/04/ethiopia-faster-rate-millionaires-
michael-buerk
• Shrestha RR et al., “Application of constructed wetlands for wastewater
treatment in Nepal”, Water, Science and Technology 44 (2011) :381-6
• Shumacher, E. F., “Small is Beautiful” Blond and Briggs, London, 1973

P a g e | 101
• Tammisetti, R “Research on the Effectiveness of Using Cloth as a Filter to Remove
Turbidity from Water” 2010
• “ Technology Transfer: The History” Industrial Partnerships Office, accessed December,
2013 https:/ipo.llnl.gov
• The United Nations World Water Development Report 2015. Paris: [United
Nations Educational, Scientific and Cultural Organization], 2015.
• Tigabu, T Semu, G, 2008 -Tigabu, Tewodros, and Girma Semu. "Addis Ababa:
Urban Profile."United Nations Human Settlements Programme (UN-HABITAT), 2008.
• Tjandraatmadja et al. 2012 ).Tjandraatmadja et al., “A Decision Support
Methodology for Integrated Urban Water Management in Remote Settlements” Water
Resour Manage (2012) 27:433–449
• Tolon, Uni ” Comparison of Urban Upgrading Projects on Development
Cooperation in Ethiopia” 2008
• Uchida, O. “Technology Transfer” In The Era of Industrialisation, edited by
Shunsaku Nishikawa and Takeji Abe. Vol. 4 of A History of the Japanese Economy,
Iwanami Shoten,1990
• “Urban Inequalities Report : Addis Ababa” Cities and Citizens Series, UN Habitat,
2004
• Van Rooijen, D., and G. Gebre. "Urban Water Pollution and Irrigated Vegetable
Farming in Addis Ababa." 2009
• http://www.instructables.com/id/Water-Filtration-using-Fabric/?ALLSTEPS.
• "Water Scarcity." WorldWildlife.org. Accessed November 2013 .
http://www.worldwildlife.org/threats/water-scarcity.
• World Health Organization’s fact file - Coping with water scarcity. Challenge of
the twenty- first century. UN-Water, FAO, 2007

Fitse Gelaye Thesis Submission

More Related Content

What's hot

Viewers also liked

Similar to Fitse Gelaye Thesis Submission

Fitse Gelaye Thesis Submission