an urban sanitation primer pete kolsky, wsp hq [email protected]
TRANSCRIPT
An urban sanitation primer
Pete Kolsky, WSP [email protected]
Perspectives/prejudices A primer… basic and not detailed
not intended to insult anybody’s intelligence or competence
Public health perspective A preoccupation with basic needs
Reaching those with “no access” Myths? More like “science and
folklore” Will try to distinguish the two
Definitions of sanitation1. “Safe interaction with human excreta”2. “Facilities required for safe management
of excreta…not hygiene promotion”3. Environmental sanitation
The environmental services required for healthy living…includes water supply, sanitation, drainage, solid waste management, etc.
For this presentation, will lean towards 2nd definition
The good news in sanitation…
747 million gained access to sanitation from 1990 to 2000!
Population Served
1990Million
s
2000Millions
%Change
Urban 1877 2442 30%
Rural 1028 1210 18%
Total 2905 3652 26%
…and the bad news
Because of population growth, there were 42 million more without access over the decade!
And these numbers are probably optimistic!
Population Unserved
1990Millions
2000Millions
%Change
Urban 415 403 -3%
Rural 1946 2000 +3%
Total 2361 2403 +2%
Sanitation and disease Diarrhoea
2.2 million deaths/year worldwide > 4 lakh in India alone…1000/day = 40/hr 1 billion episodes of diarrhoea per year in
India…2-3 episodes/child/year Most vulnerable (and most infectious) are
under 5…mostly under 2 Yet many believe that child’s faeces are
“safe” Worms (Hookworm, roundworm)
Billions of cases Transmitted through soil contamination
The F-diagramme
Faeces
Fluids
New Victi
m
Fingers
Flies
Fields/Floors
Food
Implications for sanitation & health
Sanitation is more than “keeping water supplies clean” Other routes are generally more
important Hardware without hygiene will get
us nowhere The biggest and toughest challenge
is management of faeces of kids < 2
Basic technical factors Your water supply and disposal determine
your sanitation options…
All four present in many South Asian cities
Water?
Disposal
Little wastewate
r
Lots of wastewate
r
Onsite Latrines, TPPF
Septic tanks, soakaways
Offsite Conservancy Sewerage
On-site, little water Pit latrine Principles:
Isolate the waste from human contact When full, dig new pit, seal old one. Store for > 1 year to reduce/eliminate risk Empty, recycle/dispose of contents (sludge)
Problems/challenges: High water table, rocky soils Sludge management needs to be
considered No sullage (“grey” water) management
Twin-Pit Pour Flush
Principles: Water-flush and seal controls odours Brick in diversion box blocks off filled pit for one
year before emptying, recycling compost Disadvantages:
As with pit latrine, except smell, easier alternation
Diversion box
Water-sealed slab
Pits
EcoSan Latrine contents “stabilized” after a
year’s isolation…can use as compost Basis of Twin Pit Pour Flush
EcoSan focus on urine separation…use urine as ammonia source, solids stabilize better
Build above ground to facilitate emptying
EcoSan (cont’d) Question: If we can’t sell the most
basic on-site sanitation at 500 Rs/HH, why do we think we can sell more expensive EcoSan? When economics of compost used as
justification, check market very carefully Areas of high GW table, rocky soil,
extra cost of EcoSan relatively small…
On-site, lots of water (septic tanks)
Principles: Solids settle out before sewage seeps into soil…soil
then filters sewage Problems:
Cannot “seep” into clay or plugged soil or high WT Sludge mgemt: must empty from time to time, and
where does sludge go?
Settled
sludge
Scum
Gravel-filled infiltration bed,
open-jointed pipe
On-site sanitation and groundwater
On-site sanitation systems can contaminate groundwater, esp. in areas of high GW table.
Can often be controlled by adequate distance (15m in most soils)
Where perceived as a problem…1. Is groundwater used for water supply?2. Is alternative water supply cheaper/easier
than not doing on-site sanitation?
Off-site, little water “Conservancy” or bucket/basket
system Rightly condemned as hazardous
to its workers but… …Where it exists, do we deny it? …Can we improve it?
Off-site: lots of water Sewerage! The engineer’s favourite!! Principle:
Water carries excreta through pipes to treatment works…
Problems/challenges: Expensive!!!! Needs a steady water supply A lot goes into rivers untreated… …and most sewage ttmt protects fish, not
people…
It’s all got to go somewhere…
Seweragea) Consider outlet/informal reuse carefullyb) Sludge…where does it go?
Septic tanks, pit latrines, TPPFa) Sludge management…how handled?
1) Wet sludge (septic tanks) decentral. ttmt2) Dry sludge from latrines solid waste
chain?
Public health notions of sewage treatment
How do you know sewage is bad? Smell Colour Dead fish Algae Sludge banks
If somebody removed all those problems, would the water be OK?
What sewage treatment does
Removes solids (SS) Removes organic load that depletes
oxygen that kills fish (BOD) Some removes nutrients for algae (N, P) VERY FEW REMOVE PATHOGENS
As Klaus said this morning, detention time & sunlight are your best disinfectants
Chlorination is NOT a straightforward solution Organic demand + particles poor disinfection
Nature of the challenge Lack of demand Lack of interest (political will) Lack of ownership It’s not cheap It involves deep psycho-cultural issues Like all public goods, subject to politics Often technically difficult (esp. urban) Hygiene promotion is poorly understood… …other than that, it’s straightforward!
Particularly urban issues Urban sanitation matters more…
Higher population densities More likely to be complicated by water to
spread muck around Institutional challenges, and
opportunities, are more complex Role of utility for wastewater? Role of utility for onsite sanitation? Heterogeneous populations, “communities”
WardCity
River & Environs
Peri-domestic
(street, school, work-place)
Home
Sewage Treatment
Plant
Home
Peri-domestic
WardCity
River & Environs
(street, school,
work-place)
Outfall
Collector
Primary network Secondary
network
House Connection
What’s the point? Household perception matches
public health perception! FIRST get it out of the home, THEN
out of street, THEN address overall city waste management issues
Engineers/managers perception of priorities is in reverse for variety of reasons (cost, complexity, prestige)
Peri-domestic
Ward
City
(street,school, workplace)
Home
Central Treatment Works
Primary Sewers
Secondary Sewers
House Connections
Three network approaches Slum networking (Parikh)
Slums located along the “waste collectors” of the city…
If you upgrade these collectors, marginal cost of serving slums is small…include them!
Orangi Pilot Project model HH and street organise, manage construction
of secondary (street) infrastructure; Municipality/utility manages primaries and ttmt
Condominial (Latin America, utility driven) Similar to OPP, more integrated into planning,
various contract options for maintenance
Generic institutional issues Who’s doing it now?
Sanitation is like housing… 1. People do for themselves 2. Largely informal arrangements
Who’s responsible in gov’t? Health dep’t Water dep’t …Neither of whom is necessarily appropriate…
How well can formal meet informal? How can we nudge, cajole, promote the
evolution of the mix in the right direction?
Scaling up? Definition?
Increased volume of facility construction and use
Sustainable Do we mean
“How can we get 300,000 new latrines a year?”
OR “How can we build a sustainable industry?”
Why is scaling up difficult? “How come we have great projects and
lousy programmes?” Intensity of commitment
High % ownership of commitment on pilots Span of control
Complex interventions handled at project level Capacity
How many good NGOs/agencies are there? Calibre of staff…All the good ones are taken…
Sustainable industry requirements
If somebody can make a buck out of it, it will expand…if they can’t, it won’t…
Demand Why people want sanitation (demand study in
Philippines) 1. lack of smell and flies2. cleaner surroundings3. privacy4. less embarrassment when friends visit5. less gastrointestinal disease
Yet how do we sell it? “No demand without tenure!!”
Sanitation as a business Good sensible marketing
Offer a range of options… At least as important “Design to price”
(Midnapur a good example) Understand/facilitate the growth of
the industry Subsidies? Cash flow? Materials?
Hygiene Promotion & Sanitation Marketing
Hygiene promotio
n
Sanitation
Marketing
What’s being promoted? Behaviour Hardware
Could you sell it for money?
No Yes
Does it cost a lot of cash? No Yes
Does it involve credit? No Often
Does it require constant attention?
Yes No
Prime audiences? Whole family Purse holder
Who is likely to do it? Health workers
Masons
Is it easy to monitor? No Yes
Some Principles of Hygiene Promotion
3 priorities Hand-washing at right times with soap (or
other agent?) Safe disposal of faeces Safe management of water
DON’T add more messages Repeat often Be positive, don’t preach…Avoid
Doctors, Death and Diarrhoea
Appropriate gov’t support Clear consistent policy framework
Clear leadership, clear authority (esp. urban) Enabler not provider…
Five-year (production) plan died with the Soviet Union
Start from a mix of technologies, move to another mix of technologies with greater coverage…but not through direct provision
Subsidize promotion, not production
Strong encouragement of individual HHs… examples of Midnapur, Vietnam (likely)
Some credit issues/options Sanitation is like a bridge…
…building 90% doesn’t count for much!
Therefore a “lumpy” investment Credit issues
South Asia the home of micro-credit… You can tell me more than I can tell you!!
One example from Vietnam…
Revolving funds for sanitation: Vietnam
A credit system for household sanitation improvement (latrines, septic tanks, sewerage connections)
Women’s Union manages the credit through savings-credit groups
A linkage with income generation and public awareness of health/environment issues
Target: Low income families Coverage of 80-90% of HH in city (approx
14,000)
Saving-Credit groups
Organized in groups of 12-15 persons.
Saving of 20,000 VND/mo (US $1.3) required throughout loan period
Savings provide 480,000 VND ($32 US) towards repayment of the principle
Savings can be on-lent to other savings-credit group members for income generation.
Achievement so far (April 2002)
High number of borrowers Over 350 Savings-Credit Groups formed Over 4000 borrowers in less than 1 year
80% of borrowers construct their household’s sanitation facility within two months of receiving the loan
Nearly all of sanitation facilities are constructed within three months of disbursement
High repayment rate 95 %
Main points of the news1. Put sanitation in public health context
Means to an end, not an end in itself Kids < 2 most important of all Household most important focus of intervention
2. The biggest issue is behaviour change Hygiene issues, barely touched on here Must learn to market sanitation at both
household and community Hygiene is hard-to-monitor, not as popular as
sanitation hardware for project funding
Main points of news (cont’d)
3. Generating demand There is no gain in providing sanitation
people don’t want Hygiene promotion ≠sanitation marketing
4. What’s the problem you have to solve? Must consider on-site/off-site, water/w.o. water to
define options
5. The ring diagrammes Helps to keep priorities clear for interventions Helps to identify breakdowns in “the faecal
chain”…don’t forget sludge management!!
Main points of news (cont’d)
6. Institutional realism The five-year plan forces what is not
wanted…and will be self-defeating Trying to nudge, cajole, promote, steer a
shift in mix from “now” to a better “future” Need clear leadership and accountability in
gov’t Defining the mix of formal/informal and the
role of utility
7. Credit/finance matters Micro-credit worth exploring
Some provisional principles
Sanitation cannot be only for the poor Plenty of “middle-class slums” with appalling
sanitation… there is no excuse! Need to “segment” the market to build an
industry…internal cross-subsidy? Sanitation promotion through status?
Start where you are…not where you want to be
Don’t race to transform with alien technology people don’t understand, haven’t experienced
Work with those who are currently providing the service…learn from their reality
Provisional principles (2) Keep mechanisms, benefits clear…
“Elimination of open defecation” a worthwhile goal, but don’t forget infants’ excreta
Public toilets, shared latrines? Need to observe behaviour before counting “lives saved”
Most sewage treatment is (a) expensive and (b) has minimal public health impact
Justification is environmental, not public health
Provisional principles (3) The perfect is the enemy of the good…
Beware of engineers’ “minimal acceptable standards of sanitation”
Design to affordable price…just like every other business Focus on excreta, not all environmental problems
Be pragmatic about subsidies Subsidize promotion more than production…When
overall demand takes off, production can remain sustainable…”people not waiting for a subsidy”
Sewerage has always been subsidized…why subsidize only those with house connections?
For sewerage, subsidize connection, not O & M
Some approaches to discuss
Developing the market Find out determinants, constraints on
demand Reduce them (redesign sanitation,
sell better, subsidize promotion, purchase?)
Support “infant industry” Get out of the way…
Approaches to discuss (2) NGO “triggering” of total
sanitation Current WSP/Wateraid/VERC work in
Bangladesh, Maharashtra How many NGOs, what scale can be
managed? Utility/CBO partnership on network
Outermost branches of “tree” managed by CBO, trunks by utility