Transcript Ch. 1. Sustainable sanitation

Ch. 1. Sustainable sanitation
- a review
Residents´ views
& actions
Management
& organisation
This challenge can be
addressed,
if
management, residents,
policies, technology and
engagement are in place
Physical arrangements
including technology
Jan-Olof Drangert, Linköping University, Sweden
1.1 Sanitary Conditions in the World
Learning objective: to become familiar with
various sanitary conditions in the world,
functions of sanitation, and to foster a
critical understanding of statistics and other
data.
Jan-Olof Drangert, Linköping University, Sweden
Sanitation – ’the silent crises’
 2.5 billion people (35% of the world's population 2010)
lack so called improved sanitation
 18% of the world's population lack safe water supply
 10% of all wastewater in developing countries is treated
 Malnutrition is a major factor making us more vulnerable
to disease and death, thus food security is important
 The combined effects of poor personal and domestic
hygiene and lack of safe water and good environmental
sanitation is considered the most important risk factor
for disease and death
Jan-Olof Drangert, Linköping University, Sweden
Proportion of households in major cities
connected to piped water and sewers
House or yard
connection for water (%)
Connected to
a sewer (%)
Africa
43
18
Asia
77
45
Latin America &
77
35
Oceania
73
15
Europe
96
82
100
96
Caribbean
North America
Source: Stockholm Water Front, No. 4 December 2007
Wastewater - collected and treated by
new
effective treatment plants (median percentage)
90
80
70
60
50
40
30
20
10
0
Africa
Asia
LA & C
America
Europe
Source: UNDP & UNICEF 2003 (Fig. 3.13)
Stormwater, solid and organic waste
Copyright: Jan-Olof Drangert
Stormwater drainage as a
conduit for solid waste
Copyright: Jan-Olof Drangert
Animals scavenging organic material
and clogged storm water drains
Jan-Olof Drangert, Linköping University, Sweden
Exercise: Upgrading environmental sanitation
in dense settlements
Thor-Axel Stenström, SMI, Sweden
before
Thor-Axel Stenström, SMI, Sweden
after
What Next?
Sanitation ladder ....... upgrading
Private dry
urinediverting toilet
Indoors:
Communal
flush
Jan-Olof Drangert, Linköping
University, Sweden
Jan-Olof Drangert, Linköping University, Sweden
Outside house:
Open
defecation
Björn Vinnerås Swedish University of Agricultural Sciences
Jan-Olof Drangert, Linköping University, Sweden
Diseases related to excreta and wastewater
(death/year)
Burden of Comments
disease*
1 800 000
62 000 000
600 000
no data
Ascariasis
3 000
1 800 000
Estimate: 1.45 billion infections,
of which 350 million suffer
adverse health effects
Hookworm
disease
3 000
60 000
Estimate: 1.3 billion infections of
which 150 million suffer adverse
health effects
Schistosomiasis
15 000
1 700 000
Hepatitis A
no data
Disease: Mortality
Diarrhoea
Typhoid
no data
99.8% of deaths occur in dev.
countries; 90% are children
Estimate: 16 million cases/year
Found in 74 countries, 200 million
estimated infected, 20 mi with
severe consequences
Estimate: 1.4 million cases/yr.
Source: WHO, 2006
* DALYs/year estimates the time lost due to disability or death from a disease compared with long life free of that disease (See Ch 3).
Sanitation coverage trends by developing region,
and urban-rural divide 1990-2010
Urban – rural divide
Source: UNICEF and World Health Organization, 2012
Improved urban sanitation coverage 2010
Proportion of the population in 59 developing
countries using both improved drinking water
sources and improved sanitation (per cent)
Source: UNICEF and World Health Organization, 2012
What sanitation is about
Traditional interpretation:
•
•
•
•
•
•
Personal and household hygiene
Clean environment incl. water
Solid waste management
Greywater disposal and treatment
Safe excreta disposal
Stormwater handling
Additional perspectives:
• Acceptance, affordable, convenience and pride
• Environmentally sustainable arrangements incl.
chemical risks and resource conservation
Jan-Olof Drangert, Linköping University, Sweden
A sanitation ladder for improved functions
7
6
5
4
3
2
1
Integrated resource management –
indicators depend on flow-stream
Nutrient & hazardous waste containment –
indicators depend on flow-stream
Nutrient reuse – (i) X% of excreted N, P, K is reused
for crop production, (ii) Y% of used water is reused
Pathogen & hazardous waste reduction – indicators
depend on flow-stream
Greywater management – (i) no stagnant water in compound or in streets,
(ii) no vectors, (iii) no avoidable pollution e.g. fat or paint residues
Access – (i) 24-hr access to facility year-round, (ii) privacy, personal security and shelter,
(iii) no smell, (iv) preferrably indoors and accessible to men, women, children, elderly
Excreta containment – (i) in use, (ii) no vectors, (iii) no faecal matter, (iv) hand-washing
facility in use (v) can withstand stormwater events
Adapted from Kvarnström et al., 2010
Sustainable - more than a catch word
The Bruntland Commission (1987) expressed sustainability as:
“…development that meets the needs of the present
without compromising the ability of future generations
to meet their own needs" …
Sustainability comprises a variety of perspectives:
Ecology, Economy, Social, Resource saving, Reuse, etc.
Sustainability criteria for sanitation arrangements may read (EcoSanRes):
- protecting and promoting human health,
- not contributing to environmental degradation or
depletion of the resource base,
- being technically and institutionally appropriate,
economically viable and socially acceptable
Jan-Olof Drangert, Linköping University, Sweden
Crucial physical boundaries for human activities
Biodiversity
loss
Land use
changes
N&P
cycles
Acid
oceans
Climate
change
Ozone
depletion
Aerosol
loading
Planetary
boundary
Freshwater Chemical
global use pollution
Source: Rockström et al., 2009
The planet is resilient
- but humans can push it over a threshold
New equilibrium
and new
disturbances
Pushed over
threshold
Resilient to human actions
Source: Rockström et al., 2009
Requirements on sanitation arrangements
Inside the home (old requirements):
- hygienic and protecting human health
- comfortable (indoors, no smell, easy to clean, security)
Outside of the home requirements (new! ):
- save resources (little/no water, reuse nutrients, little energy)
- protect the environment (ground & surface water, soil, air)
Lessons to consider:
• Requirements change over time, sometimes quickly
• Energy use is high for conveyance over long distances
and for advanced treatment technology
Jan-Olof Drangert, Linköping University, Sweden
MexicoSaving
City now
hasat20+
million
water
your
homepeople
MC
Latest opened
water source
1 km
100
km
Next?
2 km
200
km
Courtesy of Ian Adler, International Renewable Resources Institute, Mexico
Jan-Olof Drangert, Linköping University, Sweden
Reuse or disposal in the history of sanitation
Land area making use of
organic waste from the
city of Stockholm 1910
60km
Stockholm
The ”silent highway” man
rowing on river Thames
Illustration: www.CartoonStock.com.
Karl Tingsten, 1911
Epidemics rather than endemics have shaped our
views
Example 1
After John Snow discovered (1854) that cholera can be transmitted by contaminated well water, sanitary engineers focussed
their interest on organic matter in water as an indicator of faecal
contamination. Many rivers with high organic loads were
wrongly labelled as hazardous since the origin of the organic
matter was not from faeces but from humus! (Hamlin, 1990)
Example 2
Sanitary inspectors in Linköping (small town in Sweden) described the
sanitary conditions in the workers´ living quarters as deplorable with
stagnant storm water and awful smell, and causing ill health (1870s).
However, infant mortality in such areas did not differ from that in
richer areas with piped water and sewers. Lack of sanitary precaution
by all classes was the reason, and not until the general hygiene
improved did the death toll figures come down! (Nilsson 1994; Esrey, 1990)
Continued
Example 3
Water issues have been in focus to the detriment of appreciating
good sanitation. Cairncross (1989) and others have reached the
conclusion that water quantity is more important to good health
than water quality for many diseases. Enough water to clean the
hands and body, wash clothes, clean the house, etc. is more
important than improved drinking water quality at the margin.
Lesson to consider:
We need to measure the right parameters
to be able to draw useful conclusions.
Jan-Olof Drangert, Linköping University, Sweden
Sanitation
versus
Water
• Sanitation viewed as less important • Water ”will do the trick”
• People assumed to be uninterested
• Everyone wants water
• Is less of a public concern, and
attracts little public investment in
poor urban areas up to now
• Water supply is a public
concern, and attracts public
and private investments
• Residents do not perceive that they • Easy to charge for the water
pay for sanitation by eg poor health
- if the supply is regular
Lessons to consider:
• The Millennium Development Goals deal more with water than
sanitation issues, but sanitation is picking up with the new emphasis.
• Separate planning for sanitation and water leads to installation of
piped supply long before proper disposal and treatment of wastewater
Jan-Olof Drangert, Linköping University, Sweden
1.2
1.2
Resources:
From waste via reuse to sustainability ?
energy
Learning objective: to familiarise
with a coordinated view on resources,
and to understand the context and role
of sanitation.
Jan-Olof Drangert, Linköping University, Sweden
Reflections on water and plant nutrients
• Water molecules cannot be
manufactured or destroyed
• Water is renewable (sundriven cycle) everywhere
• Water available in situ (rural,
peri-urban) or imported (cities)
• Energy supplied by humans
(rural) or electricity (urban)
• 70% of global water use is
for crop production
• Phosphorus (P) cannot be
manufactured or destroyed
• P is immobile and mined in
only a few countries
• Food available in situ (rural)
or mostly imported (cities)
• Energy supplied by humans
and sun (rural) or fossil(urban)
• 90% of global rock P extraction is for crop production
• A balanced diet requires a
loan of 1300m3/yr p person
based on current practice.
This is 70 times greater than
the basic water need of 50 l
per person per day.
• A balanced diet results in
depletion of 22.5 kg/yr of
phosphate rock or 3.2 kg/yr
of P per person based on
current practices, of which
0.5 kg is found in the food.
Jan-Olof Drangert, Linköping University, Sweden
Input to and output from the food chain
choice
no
choice
agriculture
loss
households
evapotranspiration
Losses
on farm
Jan-Olof Drangert, Linköping University, Sweden
The water cycle – dynamics does the trick
Instant snap shot:
Shortage of freshwater !
Clouds
0.001%
8 days
” but, H2O is always on the move ...”
A dynamic perspective
gives a better description:
Renewable rain gives in 2000 years
as much water as is in the oceans!!!
Rivers
0.0002%
Groundwater
0.7%
Lakes 280
0.007% days
4 600 years
Oceans
96.5%
3 000 years
16 000
years
Ice caps
2.7%
Jan-Olof Drangert, Linköping University, Sweden
Annual renewal and use of fresh water
Country
H2O m3 km3/yr Rivers
Portion Total use - by
- by
/person/ total in from/to
being
per year
house- induyear
country countries used
per person holds stry
Sweden
21 110
176
+4
2%
479 m3
36%
55%
9%
Holland
680
10
+80
16 %
1 023 m3
5%
61%
34%
Saudi Ara
160
2
0
164 %
255 m3
45%
8%
47%
Lebanon
1 620
5
-1
16 %
271 m3
11%
4%
85%
India
2 170
1 850
+235
18 %
612 m3
3%
4%
93%
2 780
590
30
9 940
35 530
2 470
76
15
2
2 478
468
2 800
0
0
+56
0
0
0
1%
7%
97 %
19 %
4%
16 %
36 m3
48 m3
1 202 m3
2 162 m3
1 625 m3
462 m3
21%
27%
7%
12%
6%
6%
5%
11%
5%
46%
5%
7%
74%
62%
88%
42%
89%
87%
Tanzania
Kenya
Egypt
USA
Chile
China
- by
agriculture
Source: P. Gleick, 1993
Global scarcity of plant nutrients a new driving factor for sanitation
•
Phosphorus is a limited resource, and large untapped
reserves will eventually only be found on sea shelves
and as anthropogenic depositions in lake sediments.
•
95% of mined potash goes to the fertiliser industry and
has no substitute. Mines exhausted in some 50 years.
•
60% of mined sulphur goes to fertilizer industry and
has no substitute. Mines exhausted in some 20 years.
•
Costly to recover these plant nutrients from lake
sediments compared to trapping them directly at the
source i.e.as output from households and industries.
•
Nitrogen can be manufactured from the N in the air,
but this requires much energy (1 litre of oil to produce
1 kg of nitrogen).
D. Cordell & J-O Drangert, Linköping University, Sweden
Phosphate Rock – Worldwide Estimates
(thousands of metric tons)
P scarcity is worse than oil scarcity
because P CANNOT be substituted
in food production
Courtesy of Ian Caldwell, Stockholm Envrionment Institute, Sweden
Food, water and nutrient flows
0.9 l
H2O
food
1.5 l
transpiration &
evaporation
1.1 l
Faeces:
0.15 l
Urine: 1.5 l
+ nutrients
+ nutrients
Jan-Olof Drangert, Linköping University, Sweden
NUTRIENTS – and demography
Billion
people
9
World Total
16th - 21st century
6
21th
century
20th
century urban
3
rural
1500
1600
1700
1800
1900
2000
2100
Jan-Olof Drangert, Linköping University, Sweden
Actual reuse of nutrients
for urban agriculture & food security
(in Swedish towns 1850 – 2000)
Proportion nutrients
being reused
100%
Glass, tins,
ceramics
Heavy
metals
50%
waste pits + urine diversion
1870
+WC
only WC
1910
1950
+WWTP
stop
2000
Jan-Olof Drangert, Linköping University, Sweden
Human resources: capacity to manage
sanitation arrangements
Level of
management
WWTP,
Utility
sewerage
flush
toilet,
water
supply,
sewerage
Household
urineGrease diverting
trap,
toilet
pit latrine
Work hours
Paying fees
User
contribution
Jan-Olof Drangert, Linköping University, Sweden
”Manpower blindness”:
driver of new responsibility sharing
Our pre-conceived views play a role
• We tend to account only for what is done by
governments and projects in water and sanitation
• What is done by residents and small entrepreneurs
is rarely appreciated, if at all recognized (blindness)
• Yet, many urbanites survive thanks to such local
initiatives
• Here, we pledge that both kinds of activities are
needed to solve current sanitation problems
Jan-Olof Drangert, Linköping University, Sweden
1.3
1.3
Resource Flows
From where do resources come,
and where do they end up?
Linear flow
Jan-Olof Drangert, Linköping University, Sweden
Features of present policies and practices –
and an anticipated paradigm shift
• Prime fertile soils converted to town areas
• Reduced recycling of organic material
• Less urban agriculture, etc.
More linear flows
while we instead need more short loops for substances
J-O Drangert, Linköping University, Sweden
What comes in ……
Water 
20-200 kg/p/day
Food

1-2 kg/p/day
household
Consumer
goods 
Energy

1- ? kg/p/day
> 1 kg/p/day
Jan-Olof Drangert, Linköping University, Sweden
… must go out
Urine
1.5-3 kg/d/p
Faeces
0.3 kg/d/p
pollutants
Greywater 
20-200 kg/p/day
household
Solid waste
1 - ? kg/d/p
Jan-Olof Drangert, Linköping University, Sweden
The trick is to bend today´s many linear
resource flows
• Solid waste is the most visible output. It may be
discarded or sorted and recycled. Scavengers perform
an important service
• Faecal matter is very small in volume, but is a major
health threat unless treated and used wisely
• Urine (urine) volumes are small. Bad odour may be a
problem unless urine is returned to the soil
• Greywater is voluminous and a major challenge in
dense areas but can be a useful product if handled well
• Stormwater may be a serious problem but harvesting it
can augment household and irrigation water supplies
• Energy is invisible but heat may be recovered
Jan-Olof Drangert, Linköping University, Sweden
Water and nutrient ’kretslopp’
food
Rural home
City with
linear flows
Wastewater = (greywater,
urine, and faeces)
food
Wastewater
WWTP
water
Leaking
pipes
Sorting
city
J-O Drangert, Linköping University, Sweden
Three examples of ’kretslopp’ thinking
Fraction:
In Stockholm
Solid ‘waste’
sorted
in 8 fractions,
Provides
collected and reused
In Kimberley
No sorting, burnt in situ,
the rest to landfill
heating/energy
No sorting, collected
and put on landfills
Organic ‘waste’
Faecal matter
Urine (urine)
Greywater
Stormwater
organics composted
Provides
together
with soil
hygienconditioner
ised dry faecal
material
In Kampala
banana peels etc to
animal
feed
Soil conditioner
dried
and composted
Soil conditioner
dried
composted
Soil and
conditioner
collected and trucked
toLiquid
farm fertiliser
used in situ or by
Liquid
fertiliser
truck
to council
gardens
in situ or collected
in situ after
Irrigation
water
biological
treatment
Greywater to pond
after biological
treatment, and
rainwater to the
same pond. Little
rain.
Infiltrated in situ and to
drains
and biogas
infiltration
(no heavy
Groundwater
rains)
recharge
Liquid fertiliser
In drains but flooding
due to heavy rains
Jan-Olof Drangert, Linköping University, Sweden
Where do we go from here?
S
u
s
t
a
i
n
a
b
i
l
i
t
y
- protecting & promoting human
health,
- not contributing to
environmental degradation or
depletion of resource base,
Solid
- being technically and
institutionally appropriate,
waste
economically viable and
socially acceptable
Interpretation
of the ’waste
hierarchy’
NEW! Reduce generation and
polluting content in goods
Reuse/recycle
Incinerate
Land
fill
Sludge
Liquid
waste
Reuse/recycle
Polluting
discharges
Jan-Olof Drangert, Linköping University, Sweden
Material Flow Analysis for human settlements
MFA uses the principle of mass balance:
input = output + accumulated stock in the system
and provides a systematic description of the flow of
goods, materials or substances through various
processes and out of the system.
output
Process 1
input
Process 3
Process 2
output
Jan-Olof Drangert, Linköping University, Sweden
A resource flow model for a hamlet
46
Courtesy of Jenny Aragundy, Ecuador
The Stockholm model to improve sustainability
47
Courtesy of Stockholm Water Company
Modelling the situation (MFA)
• Select the material,
product or chemical you
are interested in
• Decide
the boundaries of
your system (dashed line)
• Include all the flows, uses,
losses and disposals
agriculture
• Find estimates for
all flows and stocks
food
consumption
urine
faeces
livestock
waste
handling
deposit/
landfill
4 STEPS in modelling:
hydrosphere
Description of the system
(2) Formulation of model equations, (3) Calibration, and
(4) Simulation incl. sensitivity and uncertainty analysis
(1)
Jan-Olof Drangert, Linköping University, Sweden
Actual reuse of nutrients
from urban households in agriculture
Example 1:
Proportion
being reused
100%
Glass, tins,
ceramics
Heavy
metals
50%
waste pits
+urine diversion +WC
1910
1870
only WC
1950
+WWTP
stop
2000
Jan-Olof Drangert, Linköping University, Sweden
Ex. 1 cont.:
Examples of ranges for parameters
Table 1: Data for the pri mar y and s econdar y was te tre atment for Li nköping, 1870 -2000
Year
No of
inhabitants
Primary was te treatment/
toilet s ys tem
0% WC
10% water-tight buckets
90% dug pit/outhous e
2% WC
5% urine s eparation
30% water-tight buckets
63% dug pit or equiv.
8% WC
16% urine s eparation
76% water-tight buckets
0% pit latrine or equiv.
20% WC
10% urine s eparation
70% water-tight buckets
50% WC
0% urine s eparation
50% water-tight buckets
1870
7 300
1885
10 700
1900
14 500
1920
26 900
1940
38 650
1950
54 500
90% WC
10% water-tight buckets
1975
78 000
100% W C
Co mments
Level 3
bas ed on (1)
Level 3
bas es on (1)
80-100% to s oil
0-20% to anima l
fodder
Level 3
bas ed on (1)
80-100% to s oil
0-20% to anima l
fodder
Level 3
bas ed on (2)
95-100% to s oil
0-5% to animal
fodder
Level 2
(3)
40-60% to s oil
40-60 % to landfill
Level 2
(4)
was tewater treatment
plant (WWTP), no P
reduction unit
WWTP with 90% of
P to s ludge;
0-20% to plant/s oil
WWTP with 95% of
P to s ludge;
20-30 % reus ed
(of which 2/ 3 to
energy fores t and 1/3
to farmers )
70-80% to landfill
WWTP with 97% of
P to s ludge;
21% reus ed (10-40%)
(of which 2/ 3 to
energy fores t and 1/3
to farmers )
79% to landfill
(6), (7)
1990
82 600
100% W C
(5), (6), (9)
2000
94 000
100% W C
(5), (8), (9)
Sources :
Neset and Drangert, 2010
Secondary was te
treatment or s torage
70-90% to s oil
10-30% to anima l
fodder
Co mments
60% of W C
connected to WWTP
All W C connected to
WWTP
s ame as s umptions as
for the year 2000
Ex. 1 con´t
Sensitivity analysis
Phosphorus reuse and phosphorus losses 1870-2000
The filled curves represent calculated averages, while
coloured areas between the dotted curves indicate
uncertainty ranges due to estimated input data
(in kg phosphorus per capita per year)
Source: Neset and Drangert, 2010
Example 2:
Eutrophication of Lake Dianchi, China
Production
Consumption
385 tonnes
Farmland
P leakage
55% of TP
33 tonnes
Kunming city
Jan-Olof Drangert, Linköping University, Sweden
Ex. 2 Con't
Urban P flow
to Dianchi Lake, China
Dianchi
roof runoff
street runoff
denitrification
runoff
industrial
discharge
separate
storm water
drainage
storm sewer
wrong
connection
bath
sludge
kitchen
laundry
HH
urine flush
comb. sewer
WWTP
CSO
tank
faeces flush
infiltration incl.
river water
treated
wastewater
overflow out
of CSO tank
overflow out
of combined
sewer
exfiltration
Source: Huang et al., 2007
Ex 2 Con't
Outcome to guide a new strategy
1. A major problem is that during heavy rains the wastewater
bypasses the WWTP and washes all wastewater straight
Do not mix waste streams
into the lake.
2. Groundwater and stormwater enter the poor-quality sewers
and make up a large portion of the water coming to the
WWTP
Infiltrate rainwater locally
3. Even with the best available treatment technology (BAT with
98% P removal etc.) the discharge would still be twice what
the lake can accommodate.
Source separate urine
4. Source-control measures such as urine-diversion toilets and
P-free detergents and body care products are required to
avoid discharging untreated wastewater downstream the
lake and, thus, just moving the environmental problems.
Source: adjusted from Huang et al., 2007
Example 3 :
P flows through Hanoi City
Source: Montangero et al., 2004
Ex. 3 con't
Phosphorus flows in Hanoi City
Organic waste
collection
Water
supply
Households
On-site
sanitation
Sewerage
& drainage
Market
Agriculture
Landfill
Composting
Courtesy of Agnes Montangero, 2007
Ex. 3 con't:
2007
(3 M)
Feeding the people of Hanoi
- a sensitivity analysis
Business No septic
as usual
tanks
No-meat
diet
2015 (5 M residents)
Source: Montangero et al., 2007
Nutrients and food securitya simplified global mass balance
Example 4:
Source: Clift and Shaw 2011, based on Cordell and others
Ex 4 con't
Securing a sustainable phosphorus future
The future is not all dark!
Strategies for sanitation improvements
Principle:
• Organic ≠ other solid waste
• Stormwater ≠ sewage
• Industrial ≠ household wastewater
• Black toilet water ≠ greywater
• Faeces ≠ urine
Jan-Olof Drangert, Linköping University, Sweden
1.4
1.4 Demographic Change
Learning objectives: to gain
insights about the role of
demography in sanitation planning
and implementation
Jan-Olof Drangert, Linköping University, Sweden
The Urban Sanitation Challenge
World population (in billions):
2000
2050 (estimate)
Total
6
9.3
Rural
3
3
Urban
3
6
Thus, new housing on virgin land in new cities provides
excellent opportunities for new sanitation options to fulfil the
Millennium Development Goals for sanitation
Jan-Olof Drangert, Linköping University, Sweden
Population growth rates and the proportion living
in informal settlements: means for the largest cities (%)
%
30
25
20
Informal settlements
Population growth/year
15
10
5
LA & C = Latin America
and the Caribbean
0
Africa
Asia
LA & C Oceania Europe
Source: UNDP & Unicef, 2003
City council capacity to do its part
%
Proportion of wastewater being effectively treated
90
80
70
60
Treated
wastewater
50
40
30
20
10
0
Africa
Asia
LA & C
America
Europe
Source: UNDP & Unicef, 2003
Evolution of the relationship between
residents and utilities in Sweden
subscriber
1970
customer
1990
partner
Time
Supply of water
All want to connect
H2Olaw
All water can be
cleaned
Simple treatment
plants
Jan-Olof Drangert, Linköping University, Sweden
Price
Demand
Envir.
law
Cannot treat all
water at
acceptable cost
Demographic patterns are decisive:
The growth-infrastructure hypotheses
Population
transition
transition
Time
Slow development of the
infrastructure
Lowering portion or even
absolute decrease of
infrastructure
Rapid
improvement
Jan-Olof Drangert, Linköping University, Sweden
How to manage sanitation arrangements?
A key question is about control, not degree of centralisation. Two extremes:
Turn-key management where a utility (private or public)
provides the service and the residents just pay the bill
Own-key management where single households or housing
associations initiate, build and control, while they put to use
available skills, materials, and other local resources
WC &
sewerage
Septic
tank
Turn-key
Dry urinediverting toilet
Own-key
Aqua privy
Dug latrine
Jan-Olof Drangert. Linköping University, Sweden
Example 1:
Evolution of w&s in Kisumu town, Kenya
Population
350,000
300,000
200,000
100,000
Independence
50,000
1900
Ownkey
Turn-key
1950 1963
2000
Source: Drangert et al., 2002
Norrköping (in
Example 2: Evolution
thousands)
of w&s in Norrköping, Sweden
Norrköping
140
(thousands)
Town area
expansion
120
Town area
expansion
100
80
p ip e d w a t e r
Town area
expansion
s e w e ra g e
wc
N o rrk ö p in g
60
First
piped
water
40
20
00
20
90
19
80
19
70
19
60
19
50
19
40
19
30
19
20
19
10
19
00
19
90
18
80
18
70
18
60
18
18
50
0
Source: Drangert & Hallström, 2002
Hypotheses on best management option
Population
transition
transition
proportions
Time
Turn-key
own-key
Turn-key
own-key
Turn-key
own-key
Jan-Olof Drangert, Linköping University, Sweden
Economicdevelopment
Development and Water
Supply
in ain
' Secondary
city' UK
Economic
and
W&S
Cranfield,
National GDP per person real with 0.88% and 2.15% per year trend lines
National GDP per person real with 0.88% and 2.15% per year trend lines
$40,000
$35,000
$30,000
$25,000
$20,000
Water Closets becoming popular in capital city
Newly installed WCs discharging to ditches, Hagley Road
Ordure is emptied anywhere at nightfall;
The city’s first public wash house opened in Kent Street
Mind where you tread, Sir, for the children have been here'
One third of city using unimproved pit latrines
First sewage farm acquired
City trying to convert to bucket latrines as
improvement
'One in three artisan families still had to share external
toilet with neighbours'
45% households access bucket latrines (1 per 10 HHs)
15% using unimproved pit latrines;
Over half houses get WCs - most still outside
open 'drainage [in one slum court] is so
vile that the air seems positively putrid'
20% lacking a WC
Still shared toilets for slums
High-inc
$15,000
Present upper
$10,000
middle-income
Household toilets generally achieved
Present lower middle-income
$5,000
Present low-income economies average GNI pc at PPP
'Cost reflective tariffs' required for newly
privatised providers (300 year sewer
replacement cycle?)
Source: Cranfield university, UK
20
00
19
75
19
50
19
25
19
00
18
75
18
50
18
25
18
00
$0
Evolution of indoor water taps in rural Sweden
10 Mil
90%
100%
BUT, what about the
impact of urbanisation?
63%
5 Mil
50%
70%
29%
17%
10%
1900
1950
2000
Gradual improvement towards full coverage
Jan-Olof Drangert, Linköping University, Sweden
Why do we often act as if we were only a
few hundred million people on earth?
• Small farmers understand and
practise reuse, but urban residents
do not
• Ever more people live in big villages,
towns and cities
• Most farmers have had access to
chemical fertilisers this far
• Change comes with a cost
• But, there is also a saving;
better food security
Local experience
global understanding
However: We still act as
if we were a few hundred
million people on earth!
Jan-Olof Drangert, Linköping University, Sweden