Options for the Provision of
Safe Drinking Water in
Developing Countries
Daniele Lantagne, PE
Foodborne & Diarrheal Disease Branch
The Safe Water System Initiative is one of the Type II partnerships that
emerged from the World Summit on Sustainable Development in
Johannesburg. It is an initiative that CDC helped develop, and that is now
being implemented with multiple partners including WHO, CARE, USAID,
and UNICEF. The Safe Water System itself is an “alternative low-cost water
and sanitation solution” that has at its core “Health”, which, for CDC at least,
is the most critical water issue.
1
Objectives
• Review current need for safe water
– Global context
• Demonstrate options for safe water
• Talk about research possibilities
2
What is safe water?
• Water that does not cause morbidity and/or mortality
– Especially in children under-5
• Engineering
– Indicators (fecal, total coliform and E. coli)
– Assumption that ‘protected sources’ are safe water
• Link between epidemiologists and engineers critical
3
Global Burden of Unsafe Water
• Over 1 billion persons have no
access to improved water sources
• Hundreds of millions
more drink unsafe water
from “improved” sources
An estimated 1.1 billion persons worldwide have no access to improved water
sources, relying on unsafe surface sources such as ponds, streams, and shallow
wells like these children are using for their water needs. In addition, hundreds
of millions more collect their drinking water from “improved sources”, such as
the poorly functioning municipal water system this woman has accessed, that
deliver un-chlorinated water contaminated with human and animal fecal waste,
and with the bacteria that cause cholera, dysentery, typhoid fever and so many
other waterborne diseases. Please note that whether the source is improved or
unimproved, in both photos and in hundreds of millions of families across the
globe, water is collected outside and often far from the home, primarily by
women and children, and that it is then carried, often in open plastic pails or
buckets back to the house where it is stored, and used for drinking, washing,
cooking, and bathing until another trip to the source is required.
4
Mortality and Morbidity From Unsafe
Drinking Water
• Each year:
– 1.7-2.2 million people die of diarrhea
• Each day:
– 5,000 children die from infectious diarrhea
acquired from unsafe drinking water
• Each year:
– 1 billion episodes of diarrhea are caused
Each year, an estimated 1.7 to 2.2 million persons die from waterborne
diseases. Most of these deaths are due to diarrheal diseases, and most occur in
children and other vulnerable populations. More bluntly put, approximately
5,000 children die every day from diarrhea acquired from unsafe drinking
water. The total burden of morbidity due to unsafe drinking water is difficult
to estimate, but over 1 billion episodes of gastroenteritis and other infections
annually are attributed to it each year.
5
UN Millenium Development Goals
• Widely accepted development goals
– Sustainable development, poverty alleviation
• Water
– Reduce in half the population w/out improved
water sources by 2015
– Requires 125,000 people per day gain access
• No population growth
• No loss of safe water access (conflict)
6
Where does fresh water come from?
• Global cycle
– Groundwater Diagram removed for copyright reasons.
– Surfacewater
– Rainwater
– Desalination
7
Water Scarcity
8
What contaminates water?
• Bacteria
• Parasites
– Protozoa
– Helminths
• Viruses
9
Bacteria
• Prokaryotic organisms
• Effectively inactivated by chlorine
• ~1 micron in size (filterable)
• Diseases
– Gastroenteritis (diarrhea)
– Typhoid fever
– Cholera
10
Protozoa
• Life cycle
– Excyst in intestines
– Encyst in excrement, environment
• Cyst form highly resistant to chlorine
• Large (3-10 microns), easily filtered
• Diseases
– Cryptosporidiosis, amebiasis, giardiasis
11
Viruses
• No DNA, noncellular
• Effectively inactivated by chlorine
• Very small (no filters)
• Less researched (engineering)
• Diseases:
– Gastroenteritis, hepatitis, respiratory disease
12
Size Chart
Image removed for copyright reasons.
Source: Levinson, Warren and Ernest Jawetz. Medical Microbiology & Immunology:
Examination & Board Review. Stamford, CT: Appleton & Lange, 1996.
Some data points from the chart:
- Polio virus: 0.03 micron
- HIV: 0.1 micron
- E. coli: 1 micron
- Protozoa: 10-100 micron
Reference points: Red blood cell = 6 micron, lower limit of human vision = 40 micron
13
How do we treat water?
• Processes
– Source water management • Scale
– Air stripping – Large-style
– Coagulation infrastructure
– Filtration – Community-level
– Sedimentation systems
– Ion exchange – Point-of-use
– Disinfection
Goal:
Get the dirt and microbes out, distribute
14
Historical Perspective: USA
• In 1900, diarrheal disease was one of the top ten
killers in the USA
– Typhoid, NYC
• Provision of piped, chlorinated water supply
eradicated waterborne disease in the US
• Although treatment methodologies have improved,
chlorinated piped water systems remain the
method for ensuring adequate disinfection across
the developed world
15
Graph removed for copyright reasons.
Source unknown. "Incidence of typhoid in Philadelphia during early part of 20th century."
16
Ethical Question
• Is what was right for US in early 20th century
right for developing world in early 21st century?
– Counterexample: Cell phones
– Developing: Electricity
– ?? Water supply
• How to provide safe water to > 1.1 billion?
17
Large-style Infrastructure
• Provide reliable, quality water
• However, there are limitations:
– Political
– Necessity for large investment Photo removed for copyright reasons.
– Geographical Arial view of water treatment plant.
– Time
– Cultural (pop. density)
• In light of limitations, focus in
developing countries has moved
toward community systems
18
Community Systems
• Same processes as
large-scale
• Can have a piped
distribution network
• Have simpler
process controls
and maintenance
19
Photos courtesy of of Amy Smith.
20
Photos courtesy of of Amy Smith.
21
Post-source Water Contamination:
Transport
CARE, one of our Safe Water System partners, provided this striking
photograph of a child in Mozambique carrying water home to his family. The
bucket of water is full and open, and his hands are curled into it around the top
to keep it from falling. This unavoidable hand-to-water contact means that
even the purest water from the best protected bore hole well will be
contaminated with any disease-causing agents that are on the water- bearer’s
hands even before it crosses the threshold of his or her home.
22
Post-source Water Contamination:
Storage
Inside the home, things only get worse, as illustrated by this photo taken at the
height of the cholera epidemic in Peru over a decade ago. In addition to the
buckets used for collecting and carrying water, other containers are often used
for storing water at home, but they too tend to have wide uncovered mouths.
Water is removed by dipping hands and objects in, further contaminating the
stored water with the prevalent fecal flora. At the time we took this photo,
and in the months that followed, CDC was busy helping the Pan American
Health Organization and Ministries of Health throughout the Americas try to
control the raging cholera epidemic. Water from many sources was the
principle vehicle for cholera transmission in each country. “Boil water” orders
were issued, but most persons could not afford to comply with them, and even
those who could were at risk for acquiring cholera from contamination that
occurred while the boiled water was stored unprotected at home. The long-
term cholera fix – extending piped, treated, safe water coverage to the entire
population of Latin America was projected to cost billions of dollars and take
many years to complete. So the Safe Water System was initially conceived
as an inexpensive, practical alternative that would enable families to protect
themselves from cholera and other waterborne diseases until more definitive
solutions could be implemented.
23
International Network to Promote
Household Water Treatment and
Safe Storage
‘To contribute to a significant reduction in
waterborne disease, especially among vulnerable
populations, by promoting household water
treatment and safe storage as a key component
of water, sanitation and hygiene programmes’
• Consortium
– Universities, NGO, Government, Private Sector
24
POU Treatment Types
1. Bottled
2. Filtration (Biosand, Ceramic)
3. Filtration & Chemical (PFP, GWI)
4. Chemical (Chlorine)
5. Combined chemical (PuR, P&G)
6. Ultraviolet
7. Solar (SODIS)
25
Evaluation Matrix for
Household Treatment
1. Laboratory Testing
2. Field testing
• User-monitored
• User
3. Health Impact Analysis
4. Scalability
No one intervention is silver bullet
26
Bottled
• Strengths
– Consumers avoid water collection and treatment
– Safer alternative to local water sources?
– Increased regulation for bottled water
• Limitations
– Informal street vendors are prevalent
– Consumers pay high costs for water of poor quality
• Robustness
– Significant environmental impact
• Economics
– 500 to 1000x more expensive than piped water
– 0.20 - 6.00 USD per person per day
27
Filtration
• Strengths
– Availability and range of filtration types
• Limitations
– Effectiveness risk vary greatly with approach
– Practicality, ease of use, availability, and affordability vary
– In general, low or untested rates of disease reduction
• Robustness
– Materials can be highly accessible
• Economics
– Approx. $2 for simple approaches to $200 for more complex
28
The GWI Purifier
• Two 20 L plastic
– String-wound Filter
– Check Valve
– GAC Filter
• Usage
– 5 mL bleach, 30 minutes
– 5 drops bleach in bottom
Remember to say chlorine is removed by GAC filter - so add 5 drops. These
are made in the US and imported.
293
Gift of Water, Inc.
• Florida-based NGO
• Charitable organization
– Churches in the US sponsor a village
• Installs purifiers in rural households in Haiti
– 10 communities, ~30,000 people
• Hires local technicians
– ~100 Haitian employees
302
MIT M.Eng. Theses Results
• Health Impact Study
– 35% reduction in diarrheal disease in users
– 51% reduction in diarrheal disease in under-5’s
• THM Study
– 16 / 17 samples
• Below USEPA TTHM standard
• Below WHO TTHM guideline value
• Local hypochlorite generation recommended
– Key to sustainability
31
15
Community Correct Usage
Community Percent Correct
Usage
Ferriere 100
Bas Limbe 20
Fon Veret 75
Barasa 90
Les Palmes 77
32
21
Factors for Program Success
• Dedicated and well-
selected technicians
• Localized distribution
of purifiers
• Purifiers as part of a
larger community
education initiative
33
22
The GWI System: Summary
1. Effectively reduces diarrheal disease
2. Effectively removes bacterial contamin
3. Does not pose a health risk
4. Is used correctly with TA
Benefits Drawbacks
Dependence on imported mater
High quality water Sustainability / scalability
Community development Complexity, cost
34
Potters for Peace
• Ceramic solidarity
organization
– US NGO based in Colorado
• Ceramic filter factory
– Make filters
– Impregnate with silver
– Sell to NGOs
– NGOs implement programs
358
Results: Lab Study
• No water sample exceeded guidelines for
silver in drinking water
• All flow rates of filters sold are effective at
removing bacterial indicators
• Although a majority of indicators are removed
w/out silver, the 3.2% silver is necessary for
100% removal
36
Results: Field Studies
• 14 / 24 less than 0.5 L/hr
– Correlated with filter age
• Microbial Testing: P/A
– 23/24 had detectable TC
– 19/24 had detectable H2S
– 13/17 had detectable E. coli
• Lab enumeration: MF
– More contamination in finished water
37
20
The PFP Filter: Summary
1. Silver concentrations not a health concern
2. Flow is a concern - scrubbing
3. Microbial contamination is a concern - cleaning
4. Education is vital for continued use
Benefits Drawbacks
Local production / culture Less effective in field
Inexpensive Breakage rate
Say important to do both lab and field studies.
38
32
Comparison
Two very different interventions
PFP GWI
• Sustainable • Effective
– Does not reliably reduce – Dependent on
bacterial contamination as subsidies
currently implemented – Complex
39
Biosand Filtration
Images removed for copyright reasons.
40
Chemical
• Strengths
– Clinically proven
– Residual disinfection
• Limitations
– Does not address all contaminants
– Chemical taste and smell
• Robustness
– Chemical availability
– Some storage risk
• Economics
– $7 to $11 per family per year
41
CDC Safe Water System
Treat drinking water Store treated
at the point of use drinking water safely
Dilute sodium Narrow-mouthed, lidded
hypochlorite bleach vessels with spigots
The Safe Water System is simple. It provides families with the means to treat
their drinking water at the point-of-use – by adding dilute sodium hypochlorite
bleach - and the means for them to store treated drinking water safely – in a
narrow-mouthed, lidded vessel with a spigot that can be used to collect,
transport, disinfect and store drinking water in the home. A capful of the
locally-produced dilute sodium hypochlorite from the 500 ml CLARO bottle is
just the right amount to treat 20 liters of water in the locally-produced CLARO
storage vessel. These two items were marketed together as part of the first
national Safe Water System project in Bolivia in 1996.
42
CDC Safe Water System
Consistently reduces diarrhea by 25-85%
The hypochlorite solution and the storage vessel are the “hardware” of the
Safe Water System, but the most critical component is the “software”. By that
I mean the messages and the methods used to induce and sustain healthy
changes in behavior, including safe water handling, and improvements in
hygiene and sanitation, such as handwashing. These printed materials are
from Safe Water Systm programs in Bolivia, Zambia, and Ecuador, but our
social marketing and implementation partners also reach people through radio
and TV broadcasts, community mobilization campaigns, and interpersonal
behavior change techniques such as motivational interviewing. We realized
long ago that for the Safe Water System to have impact, it needed to be
economically self-sustaining, and hence one function of the “software” is to
get people to buy the “hardware”. Fortunately, the bleach solution costs very
little to produce, and 10 to 25 cents worth will last a family an entire month.
Safe storage vessels cost between 2 and 5 dollars, but are still within the means
of many of those who can benefit from them. Increasingly, we’ve recognized
that the “hardware” also helps to sell the software. In other words, people
who purchase and bring into their homes a bottle of hypochlorite for water
treatment and a safe water storage vessel are likely to be receptive to messages
promoting simple hygiene measures like handwashing - which by the way, is a
lot easier to do when your water is kept in a vessel with a spigot. The
hardware empowers families to manage their household water and sanitation
environment better, and this reinforces their willingness to adopt and maintain
new behaviors.
43
Safe Water System Products
This is a simple picture of the actual the water treatment solution bottles that
are sold under different brand names in 7 countries, Bolivia, Peru, Zambia,
Uganda (in yellow), Kenya, India, and Madagascar.
44
SWS Implementation Plan
• Work with in-country partners
– Establish products
– Begin pilot project
• Complete evaluation of pilot project
• Establish distribution network and market product
– Social marketing
– Community health motivators
– Motivational interviewing
• Evaluate and modify plan as needed
45
Safe Water System Results
• Consistently reduces diarrhea by ~50%
Bolivia* 1994 44% overall; 53% in infants
Uzbekistan* 1996 85% overall
Zambia* 1998 48% overall
Guatemala 2001 25% overall
Madagascar* 2001 95% against cholera
Kenya 2001 55% in children <5 years old
Madagascar 2002 63% overall
Pakistan 2002 49% overall
Uganda 2003 ~30% in HIV-infected persons
46
Global burden of unsafe water
>1.1 billion persons
Safe Water System: 2003
5 million users
Unsafe Water
But as good as that makes us feel, when we leave our logarithmic scales
behind and examine our progress on a pie chart representing the billion plus
persons without safe water, we see immediately how much more needs to be
done. So how are we going to capitalize on the tremendous opportunity that
this situation presents us with? Several exciting new prospects have recently
emerged …
47
Global burden of unsafe water
>1.1 billion persons
Safe Water System: 2003 Safe Water System: 2007
5 million users 100 million users
Proposed 20 country expansion
Unsafe Water
We believe that the Safe Water System can help us reach the goal, and have
projected a figure of 100 million regular users by 2007 if we can find the
resources to support our proposed 20 country expansion.
48
PuR
• Procter & Gamble Product
– Reverse engineering from water treatment plants to POU solution
• Strength
– Clinically proven by CDC
– Residual disinfection benefits
– Visual clue of treatment - addresses turbidity
• Limitations
– More steps required for treatment
• Robustness
– Well suited for emergency situations
– Private sector involvement
• Economics
– 0.20 USD per family per day
49
Ultraviolet
• Strengths
– Addresses some hard to treat contaminants
– Treats large quantities quickly
• Limitations
– High initial costs for materials
– Contaminant reactivation over time
– Ineffective with some common contaminants
• Robustness
– Electricity availability; solar options exist
• Economics
– Electricity cost is minimal
– UV Waterworks $800 initial cost, plus $200 for solar
50
Solar Disinfection
• Strengths
– Clinically proven
– Does not address color, taste, odor
• Limitations
– Weather dependency
– Contaminant reactivation over time
– Ineffective with some common contaminants
• Robustness
– Material availability
– High level of oversight required
• Economics
– Little to no initial cost with recycled plastic bottles
– Approximately $1 per family per year
51
Opportunities for Research
• Each step of process
– Focus on end goals: feasibility, impact
• Research in developing countries
– Give something back
– Not an excuse for poor quality control
– Modified laboratory testing
– Cross-major collaborations critical
52
College Groups
• Engineers without Borders
• Engineers without Frontiers
• Guest Speakers
• Amnesty International
53
Thank you!
Daniele Lantagne
54
