fitse gelaye thesis submission

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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

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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.

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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.

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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.

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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

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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

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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

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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

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39. Figure 39: Greywater filtered through one layer of each material

40. Figure 40: Greywater filtered through multiple layers of each material

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INTRODUCTION

What if the Addis Ababa had an alternative water source?

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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,

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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

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commentary on the complex task that is technology transfer and how it should be

approached.

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PART I

Water:

Fresh, Grey and Recycled

Water, is taught by thirst.

- Emily Dickinson

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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

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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/.

http://www.iwmi.cgiar.org/

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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

http://www.worldwildlife.org/threats/water-scarcity

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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


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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

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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.

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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

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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.

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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


Federation, and the WateReuse Association, 2013 pp 12 28


Federation, and the WateReuse Association, 2013 pp 13

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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

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PART II

Adapting the Foreign

All technology should be assumed guilty until proven innocent.

-David Ross Brower

http://www.quotes.net/quote/11313

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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

http://www.ictsd.org/

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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/

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/

http://www.usa.roca.com/ourproducts/ww

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

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.

http://en.wikipedia.org/wiki/File:2006-megacities-1.png

http://en.climate-data.org/location/532/

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

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.54There 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 Shrestha RR et al., “Application of constructed wetlands for wastewater treatment in Nepal”, Water,

Science and Technology 44 (2011) :381-6

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

Shrestha RR et al., “Application of constructed wetlands for wastewater treatment in Nepal”, Water,

Science and Technology 44 (2011) :381-6 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)

http://en.wikipedia.org/wiki/Taytu_Betul

http://en.wikipedia.org/wiki/Menelik_II

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 Tigabu, T Semu, G, 2008 -Tigabu, Tewodros, and Girma Semu. "Addis Ababa: Urban Profile."United

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

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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).

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Maps

Figure 9: Map 1, Sub cities and primary roads of Addis Ababa76

76

Addis Ababa; Atlas of Key Demographic and Socio Economic Indicators” Population Affairs

Coordination Sub process Finance and Economic Development Bureau, Addis Ababa, 2010. "Google Maps." Google Maps. Accessed February 9, 2015. http://maps.google.com/.

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Figure 10: Map 2, Population Density of Addis Ababa77

77

Addis Ababa; Atlas of Key Demographic and Socio Economic Indicators” Population Affairs

Coordination Sub process Finance and Economic Development Bureau, Addis Ababa, 2010.

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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


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Figure 13: Map 5, Percentage of Poor Households in Addis Ababa, Ethiopia80

80


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Figure 14: Map 6, Location of important services 81

81

NEDECO “Wastewater Master Plan Volume II” Netherland Engineering Consultants, 2002.

"Google Maps." Google Maps. Accessed February 9, 2015. http://maps.google.com/.

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Figure 15: Map 7, Percentage of household with insufficient water supply82

82




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Figure 16: Map 8, Percentage of household with insufficient sanitation services83

83




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Figure 17: Map 9, Location of people willing to reuse greywater84

84

"Google Maps." Google Maps. Accessed February 9, 2015. http://maps.google.com/.

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Figure 18: Overlay of Map 1, Map 3 and Map 5

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Figure 19: Overlay of Map 7, Map 8 and Map 9

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Figure 20: Overlay of Map 2 , Map 4 and Map

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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.

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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.

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PART IV

Design, Construction, Trial and Redesign

To the first steps,

the small actions,

the failures

and most importantly, to the learning moments

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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,

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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

http://press-/

http://press-/

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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

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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.

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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.

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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.

http://www.reuk.co.uk/Sand-Filters-for-Greywater.htm

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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.

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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.

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Figure 26: Comprehensive list of materials

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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) .

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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

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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.

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Figure 31: Third Step of construction

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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

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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)

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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

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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.)

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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

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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

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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.

tps://confluence.cornell.edu/display/AGUACLARA/Foam%20F


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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.

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Figure 40: Greywater filtered through one layer of each material

Figure 41: Greywater filtered through multiple layers of each material

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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.

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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.

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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

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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

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fitse gelaye thesis submission

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