Monday, 19 November 2012
World Toilet Day
Today is World Toilet Day – see here and also ThePublicToilet.com. The London School of Hygiene and Tropical Medicine, in association with Domestos, has released this report which is well worth reading: Toilets for Health.
Friday, 16 November 2012
No toilet, no bride!
In the UK Daily Mail of 23 October: No toilet? Then no bride − the Indian government's bizarre new campaign to increase indoor lavatories. Well, that’s one way of promoting sanitation!
Wednesday, 31 October 2012
Top three toilets?
From the Gates Foundation website (dated 14 August): ‘Bill Gates Names Winners of the Reinvent the Toilet Challenge’:
California Institute of Technology in the United States received the $100,000 first prize for designing a solar-powered toilet that generates hydrogen and electricity. Loughborough University in the United Kingdom won the $60,000 second place prize for a toilet that produces biological charcoal, minerals, and clean water. University of Toronto in Canada won the third place prize of $40,000 for a toilet that sanitizes feces and urine and recovers resources and clean water.
More details were given in the 1 September issue of The Economist in an article entitled ‘Flushed with pride’ – you really must read this! Here’s a couple of quotes to whet your appetite:
“Urine is filtered through sand, and the resulting fluid is sterilised with ultraviolet light”
and
“A tank feeds mixed urine and faeces through a rig that heats it to 200°C under high pressure, killing pathogens”
– and these are meant to be prototypes of new household-level toilets for, I presume, the urban and rural poor!
All a bit too much, wouldn’t you say?
[I should have made this post a good few weeks ago, but ill health delayed me.]
California Institute of Technology in the United States received the $100,000 first prize for designing a solar-powered toilet that generates hydrogen and electricity. Loughborough University in the United Kingdom won the $60,000 second place prize for a toilet that produces biological charcoal, minerals, and clean water. University of Toronto in Canada won the third place prize of $40,000 for a toilet that sanitizes feces and urine and recovers resources and clean water.
More details were given in the 1 September issue of The Economist in an article entitled ‘Flushed with pride’ – you really must read this! Here’s a couple of quotes to whet your appetite:
“Urine is filtered through sand, and the resulting fluid is sterilised with ultraviolet light”
and
“A tank feeds mixed urine and faeces through a rig that heats it to 200°C under high pressure, killing pathogens”
– and these are meant to be prototypes of new household-level toilets for, I presume, the urban and rural poor!
All a bit too much, wouldn’t you say?
[I should have made this post a good few weeks ago, but ill health delayed me.]
Wednesday, 8 August 2012
Agroforestry and arborloos
In a letter to The Economist (28 July 2012) Tony Simons, Director General of the World Agroforestry Centre in Nairobi, writes that, to reduce hunger and promote food security in the Sahel, agroforestry is the way forward. As he notes, “Trees provide not only ecological resilience but also cash income, energy, environmental services, fodder for animals and nutritious fruits”. Not a mention of arborloos. When will agriculture catch up with sanitation?
Tuesday, 31 July 2012
Erdos: “World's biggest eco-toilet scheme fails”
“The dry toilets in Inner Mongolia's Daxing eco-community have been quietly replaced after three years of bad smells, health problems and maggots.” Oops! See the full entry in the Guardian Environment Network (30 July 2012).
Monday, 30 July 2012
Fossas alternas
IRC has on its website a good photo-sequence on how to build a fossa alterna: “This photo story shows you how to construct a fossa alterna, how to empty it and how to process the compost. After 12−18 months of composting it is safe to empty a fossa alterna toilet and use the compost as fertilizer for your garden soil”. Fossas alternas? Read Peter Morgan’s Toilets That Make Compost Low-cost, sanitary toilets that produce valuable compost for crops in an African context.
Friday, 27 July 2012
Rural sanitation
What Does It Take to Scale Up Rural Sanitation? by Eduardo Perez and published earlier this month by the Water and Sanitation Program is an important document because, as the report’s webpage says, “Today, 2.5 billion people live without access to improved sanitation. … Of those without access to sanitation, 75 percent live in rural areas [emphasis added].” – so there’s no escaping the importance of rural sanitation. The technologies for rural sanitation are well understood – well, most of them anyway. The report notes that “Scaling Up Rural Sanitation is designed as an evidence-based learning project with an explicit goal to test and document new approaches, reflect on challenges, and develop knowledge products to share lessons learned. Testing innovative approaches implies taking risks and learning from successes and failures.”
Yet, and it’s a big yet, there’s no mention of Arborloos – clearly a major omission!
Yet, and it’s a big yet, there’s no mention of Arborloos – clearly a major omission!
Thursday, 26 July 2012
The 2011 Pumphandle Lecture
Have a look at the John Snow Society’s 2011 Pumphandle Lecture Epidemiology for the Bottom Billion – where there’s not even a pump handle to remove! by Hans Rosling who’s a professor at the Karolinska Institute and also chairman of the Gapminder Foundation. An excellent lecture. Check out the Gapminder videos − you’ll find some pretty stunning ones!
Who’s John Snow? Find out here.
Who’s John Snow? Find out here.
Global WatSan costs
WHO published in May this year Global costs and benefits of drinking-water supply and sanitation interventions to reach the MDG target and universal coverage by Dr Guy Hutton. Here’s the Overview from the WHO webpage for the report:
This report updates previous economic analyses conducted by the World Health Organization, using new WSS coverage rates, costs of services, income levels and health indicators. Benefit-cost ratios (BCR) and costs are estimated to meet the MDG drinking-water and sanitation target and to attain universal access of basic services. Rural and urban areas are analysed as separate targets. The analysis utilises WSS coverage definitions of the JMP (WHO/UNICEF Joint Monitoring Programme for Water Supply and Sanitation).
The bottom line is: The benefit-cost ratio for the necessary interventions varies from 2.8 in the SSA region to 8.0 in E. Asia. The global economic return on sanitation spending is US$ 5.5 per US dollar invested.
A good, if somewhat exhausting, read! Read the Executive Summary at least.
This report updates previous economic analyses conducted by the World Health Organization, using new WSS coverage rates, costs of services, income levels and health indicators. Benefit-cost ratios (BCR) and costs are estimated to meet the MDG drinking-water and sanitation target and to attain universal access of basic services. Rural and urban areas are analysed as separate targets. The analysis utilises WSS coverage definitions of the JMP (WHO/UNICEF Joint Monitoring Programme for Water Supply and Sanitation).
The bottom line is: The benefit-cost ratio for the necessary interventions varies from 2.8 in the SSA region to 8.0 in E. Asia. The global economic return on sanitation spending is US$ 5.5 per US dollar invested.
A good, if somewhat exhausting, read! Read the Executive Summary at least.
Wednesday, 25 July 2012
Erdos Eco-Town Project
I’ve just received in today’s post The Challenges of Urban Ecological Sanitation Lessons from the Erdos Eco-Town Project, China, written by Arno Rosemarin, Jennifer McConville, Amparo Flores, Zhu Qiang, and published in May this year by Practical Action Publishing. The publisher’s blurb says that this book “highlights the experience of implementing the Erdos Eco-Town Project in Inner Mongolia, China. This remains the largest urban project of urine-diversion dry toilets in the world, serving a population of approximately 3000 people in 4–5 storey apartment buildings. The multi-storey collection system also links to on-site grey water treatment, a composting centre, underground urine tanks, and the agricultural reuse of nutrients. The Challenges of Urban Ecological Sanitation describes the technical design, daily operation and maintenance, costs and benefits compared to conventional systems [but not to simplified sewerage], as well as the challenges in achieving acceptability with users.”
So far I’ve only read Chapter 5 “Social acceptance” and there’s much mention of odour, but no mention of ‘dust’. Flushing the ‘ecoloo’ with sawdust creates a lot of actual dust – and this flushing could only be done while the user was still sitting on it: not a problem for men as (I suppose) they just brushed the dust off, but a major discomfort for women who found their external genitalia covered in dust. Ghastly!
Anyway I’ll be taking the book off in a couple of weeks as unmissable ‘holiday’ reading…
So far I’ve only read Chapter 5 “Social acceptance” and there’s much mention of odour, but no mention of ‘dust’. Flushing the ‘ecoloo’ with sawdust creates a lot of actual dust – and this flushing could only be done while the user was still sitting on it: not a problem for men as (I suppose) they just brushed the dust off, but a major discomfort for women who found their external genitalia covered in dust. Ghastly!
Anyway I’ll be taking the book off in a couple of weeks as unmissable ‘holiday’ reading…
Friday, 8 June 2012
Free book!
Barbara Evans and I have written a new book Sanitation and Water Supply in Low-income Countries, published by Ventus Publishing ApS, Copenhagen, 2012 – please download from the link above (all royalties go to WaterAid Sweden).
Monday, 14 May 2012
Public Expenditure on WatSan in SSA
I’ve been reading More, Better, or Different Spending? Trends in Public Expenditure on Water and Sanitation in Sub-Saharan Africa by Meike van Ginneken, Ulrik Netterstrom and Anthony Bennett (World Bank, 2012). Here’s a couple of quotes:
Looking at political dynamics also helps explain why sanitation is an orphan sector, suffering from slow technology change. Low household demand for sanitation results in politicians not seeing sanitation as a vote winner, and therefore allocating scarce resources to sectors with higher perceived political rewards. But sanitation is a cheap lifesaver [emphasis added], and as such might merit higher public spending. Mistrust of cheaper service levels and other cultural norms within the engineering profession form the background of the strong barriers to technological innovations [emphasis added].
The need for better targeting is a major conclusion of this review. This includes channelling funds to the sanitation subsector, to areas outside of the capital, and to the upkeep of existing water supply and sanitation facilities that currently appear underfunded.
A review of Public Expenditure Reviews reveals huge gaps between policy and practice. PERs can be a useful tool to hold governments accountable for the implementation of their own policies and promises. At the sector level, we found that while nearly all countries have elaborated comprehensive water sector policies and strategies, implementation and enforcement of sector reform strategies remain incomplete, and efforts are needed in terms of capacity building, general public awareness campaigns, and further development of the legal framework that would facilitate implementation of policies and strategies.
An inspiring but depressing read!
Looking at political dynamics also helps explain why sanitation is an orphan sector, suffering from slow technology change. Low household demand for sanitation results in politicians not seeing sanitation as a vote winner, and therefore allocating scarce resources to sectors with higher perceived political rewards. But sanitation is a cheap lifesaver [emphasis added], and as such might merit higher public spending. Mistrust of cheaper service levels and other cultural norms within the engineering profession form the background of the strong barriers to technological innovations [emphasis added].
The need for better targeting is a major conclusion of this review. This includes channelling funds to the sanitation subsector, to areas outside of the capital, and to the upkeep of existing water supply and sanitation facilities that currently appear underfunded.
A review of Public Expenditure Reviews reveals huge gaps between policy and practice. PERs can be a useful tool to hold governments accountable for the implementation of their own policies and promises. At the sector level, we found that while nearly all countries have elaborated comprehensive water sector policies and strategies, implementation and enforcement of sector reform strategies remain incomplete, and efforts are needed in terms of capacity building, general public awareness campaigns, and further development of the legal framework that would facilitate implementation of policies and strategies.
An inspiring but depressing read!
Saturday, 12 May 2012
Raspberry jam …
Richard Feachem prompted me to read the outstanding essay The Clash of the Counter-bureaucracy and Development by Andrew Natsios (Center for Global Development, 2010), probably the most indicting document on aid bureaucracy yet! Here’s the ‘Up-front Quote’:
Gentlemen,
Whilst marching from Portugal to a position which commands the approach to Madrid and the French forces, my officers have been diligently complying with your requests which have been sent by His Majesty’s ship from London to Lisbon and thence by dispatch to our headquarters.
We have enumerated our saddles, bridles, tents and tent poles, and all manner of sundry items for which His Majesty’s Government holds me accountable. I have dispatched reports on the character, wit and spleen of every officer. Each item and every farthing has been accounted for with two regrettable exceptions for which I beg your indulgence.
Unfortunately the sum of one shilling and ninepence remains unaccounted for in one infantry battalion’s petty cash and there has been a hideous confusion as to the number of jars of raspberry jam issued to one cavalry regiment during a sandstorm in western Spain. This reprehensible carelessness may be related to the pressure of circumstance, since we are at war with France, a fact which may come as a bit of a surprise to you gentlemen in Whitehall.
This brings me to my present purpose, which is to request elucidation of my instructions from His Majesty’s Government so that I may better understand why I am dragging an army over these barren plains. I construe that perforce it must be one of two alternative duties, as given below. I shall pursue either with the best of my ability, but I cannot do both:
1.) To train an army of uniformed British clerks in Spain for the benefit of the accountants and copy-boys in London or, perchance…
2.) To see to it the forces of Napoleon are driven out of Spain.
Your most obedient servant,
Wellington
11 August 1812
… and here’s the Abstract:
One of the little understood, but most powerful and disruptive tensions in established aid agencies lies in the clash between the compliance side of aid programs—the counter-bureaucracy—and the technical, programmatic side. The essential balance between these two in development programs has now been skewed to such a degree in the U.S. aid system (and in the World Bank as well) that the imbalance threatens program integrity. The counter-bureaucracy ignores a central principle of development theory—that those development programs that are most precisely and easily measured are the least transformational, and those programs that are most transformational are the least measurable. Relieving the tension between the counter-bureaucracy and development practice would require implementing new measurement systems, conducting more research on overregulation and its effects, reducing the layers of oversight and regulation, and aligning programmatic goals with organizational incentives.
What’s the answer? Most likely ‘output-based aid’, sometimes called ‘cash on delivery’ or ‘results-based financing’. More of this, especially in the WASH sector, to come …
PS: Still too many ‘accountants and copy-boys’ in London … and Washington and Paris and …!
Gentlemen,
Whilst marching from Portugal to a position which commands the approach to Madrid and the French forces, my officers have been diligently complying with your requests which have been sent by His Majesty’s ship from London to Lisbon and thence by dispatch to our headquarters.
We have enumerated our saddles, bridles, tents and tent poles, and all manner of sundry items for which His Majesty’s Government holds me accountable. I have dispatched reports on the character, wit and spleen of every officer. Each item and every farthing has been accounted for with two regrettable exceptions for which I beg your indulgence.
Unfortunately the sum of one shilling and ninepence remains unaccounted for in one infantry battalion’s petty cash and there has been a hideous confusion as to the number of jars of raspberry jam issued to one cavalry regiment during a sandstorm in western Spain. This reprehensible carelessness may be related to the pressure of circumstance, since we are at war with France, a fact which may come as a bit of a surprise to you gentlemen in Whitehall.
This brings me to my present purpose, which is to request elucidation of my instructions from His Majesty’s Government so that I may better understand why I am dragging an army over these barren plains. I construe that perforce it must be one of two alternative duties, as given below. I shall pursue either with the best of my ability, but I cannot do both:
1.) To train an army of uniformed British clerks in Spain for the benefit of the accountants and copy-boys in London or, perchance…
2.) To see to it the forces of Napoleon are driven out of Spain.
Your most obedient servant,
Wellington
11 August 1812
… and here’s the Abstract:
One of the little understood, but most powerful and disruptive tensions in established aid agencies lies in the clash between the compliance side of aid programs—the counter-bureaucracy—and the technical, programmatic side. The essential balance between these two in development programs has now been skewed to such a degree in the U.S. aid system (and in the World Bank as well) that the imbalance threatens program integrity. The counter-bureaucracy ignores a central principle of development theory—that those development programs that are most precisely and easily measured are the least transformational, and those programs that are most transformational are the least measurable. Relieving the tension between the counter-bureaucracy and development practice would require implementing new measurement systems, conducting more research on overregulation and its effects, reducing the layers of oversight and regulation, and aligning programmatic goals with organizational incentives.
What’s the answer? Most likely ‘output-based aid’, sometimes called ‘cash on delivery’ or ‘results-based financing’. More of this, especially in the WASH sector, to come …
PS: Still too many ‘accountants and copy-boys’ in London … and Washington and Paris and …!
Friday, 11 May 2012
Economics of inadequate sanitation in Africa
A recent World Bank/Water and Sanitation Program initiative on the economics of sanitation in 18 countries in Sub-Saharan Africa found that:
Inadequate sanitation costs [these] 18 African countries around US$5.5 billion each year [around 1−2.5% of GDP].
Open defecation alone accounts for almost US$2 billion of these annual losses in the[se] 18 countries. Lacking alternatives, more than 114 million people still defecate in the open in the 18 countries surveyed − this is about half the number of people on the continent and almost 24% of the total population in the countries surveyed. Eliminating the practice of open defecation in these countries would require about 23 million toilets to be built and used.
Each of the 18 countries has its own report (downloadable here). Fairly grim reading – but, of course, unfortunately what we're used to. Will sanitation ever get the real priority it deserves?
Inadequate sanitation costs [these] 18 African countries around US$5.5 billion each year [around 1−2.5% of GDP].
Open defecation alone accounts for almost US$2 billion of these annual losses in the[se] 18 countries. Lacking alternatives, more than 114 million people still defecate in the open in the 18 countries surveyed − this is about half the number of people on the continent and almost 24% of the total population in the countries surveyed. Eliminating the practice of open defecation in these countries would require about 23 million toilets to be built and used.
Each of the 18 countries has its own report (downloadable here). Fairly grim reading – but, of course, unfortunately what we're used to. Will sanitation ever get the real priority it deserves?
Vocational training
I received a circular email the other day from EMWIS (the Euro-Mediterranean Information System on Know-how in the Water sector) highlighting some conclusions from the recent World Water Forum, specifically on the need for vocational training and the role of the International Network of Water Training Centres [Réseau International des Centres de Formations aux Métiers de l’Eau]. Here’s a little of what it said:
Most of the staff concerned are workers who, in too many developing countries, still have little or no training! The cost of labour accounts for up to one third of the total cost of the water utility, to optimize this significant expenditure, it is essential to improve skills through basic and continuing training for these professionals. But this is an area still largely underfunded both by governments and operators and even by bi and multilateral donors who are the first to complain about the negative consequences of this situation! It would therefore be advisable to better support vocational training in the water sector through sustainable financial mechanisms. … Without planned investments in vocational training, the consequences will be:
• a limitation or even a decrease in access to quality drinking water supply, sanitation or irrigation services,
• impossibility for service managers to prevent problems,
• quick degradation of the installations that will have to be rebuilt,
• inability to operate the facilities at full capacity,
• ultimately reduction of the effectiveness of the ODA public funds.
There are hundreds of thousands of employees, at all levels, but mainly at a low level, and only speaking their local language, who are employed in water management over the world. [Training] needs are thus huge …
It all refers to water, but clearly it’s applicable to sanitation.
Remember what Professor Derek Bok (a former president of Harvard University) said: “If you think education is expensive, try ignorance”.
Most of the staff concerned are workers who, in too many developing countries, still have little or no training! The cost of labour accounts for up to one third of the total cost of the water utility, to optimize this significant expenditure, it is essential to improve skills through basic and continuing training for these professionals. But this is an area still largely underfunded both by governments and operators and even by bi and multilateral donors who are the first to complain about the negative consequences of this situation! It would therefore be advisable to better support vocational training in the water sector through sustainable financial mechanisms. … Without planned investments in vocational training, the consequences will be:
• a limitation or even a decrease in access to quality drinking water supply, sanitation or irrigation services,
• impossibility for service managers to prevent problems,
• quick degradation of the installations that will have to be rebuilt,
• inability to operate the facilities at full capacity,
• ultimately reduction of the effectiveness of the ODA public funds.
There are hundreds of thousands of employees, at all levels, but mainly at a low level, and only speaking their local language, who are employed in water management over the world. [Training] needs are thus huge …
It all refers to water, but clearly it’s applicable to sanitation.
Remember what Professor Derek Bok (a former president of Harvard University) said: “If you think education is expensive, try ignorance”.
Wednesday, 9 May 2012
YouTube videos
Some of my Microsoft Producer presentations on low-cost sanitation, low-cost sewerage. waste stabilization ponds, and wastewater use in agriculture and aquaculture have now been converted by Dr Andy Sleigh to YouTube videos and mp4 files – so you can download them and listen to them on the go!
Thursday, 8 March 2012
The latest JMP report
The joint WHO-UNICEF report Progress on Drinking Water and Sanitation:2012 Update was published yesterday. Here’s a couple of quotes:
The report brings welcome news: The MDG drinking water target, which calls for halving the proportion of the population without sustainable access to safe drinking water between 1990 and 2015, was met in 2010, five years ahead of schedule. However, the report also shows why the job is far from finished. Many still lack safe drinking water, and the world is unlikely to meet the MDG sanitation target. Continued efforts are needed to reduce urban-rural disparities and inequities associated with poverty; to dramatically increase coverage in countries in sub-Saharan Africa and Oceania; to promote global monitoring of drinking water quality; to bring sanitation ‘on track’; and to look beyond the MDG target towards universal coverage.
However:
Over 780 million people are still without access to improved sources of drinking water and 2.5 billion lack improved sanitation. If current trends continue, these numbers will remain unacceptably high in 2015: 605 million people will be without an improved drinking water source and 2.4 billion people will lack access to improved sanitation facilities.
Most of those without an improved water supply were in Sub-Saharan Africa (mainly in rural areas), and most of those without improved sanitation were in Sub-Saharan Africa, India, and the Caucasus and Central Asia.
Open defecation (OD) was still practised by 1.1 billion people in 2010 – almost a fifth of the population in developing countries. Nearly 60 per cent of those practising OD were in just one country − India.
So water supply OK (unless you’re in rural Africa) but sanitation lamentably still not OK – no surprise there then.
The report brings welcome news: The MDG drinking water target, which calls for halving the proportion of the population without sustainable access to safe drinking water between 1990 and 2015, was met in 2010, five years ahead of schedule. However, the report also shows why the job is far from finished. Many still lack safe drinking water, and the world is unlikely to meet the MDG sanitation target. Continued efforts are needed to reduce urban-rural disparities and inequities associated with poverty; to dramatically increase coverage in countries in sub-Saharan Africa and Oceania; to promote global monitoring of drinking water quality; to bring sanitation ‘on track’; and to look beyond the MDG target towards universal coverage.
However:
Over 780 million people are still without access to improved sources of drinking water and 2.5 billion lack improved sanitation. If current trends continue, these numbers will remain unacceptably high in 2015: 605 million people will be without an improved drinking water source and 2.4 billion people will lack access to improved sanitation facilities.
Most of those without an improved water supply were in Sub-Saharan Africa (mainly in rural areas), and most of those without improved sanitation were in Sub-Saharan Africa, India, and the Caucasus and Central Asia.
Open defecation (OD) was still practised by 1.1 billion people in 2010 – almost a fifth of the population in developing countries. Nearly 60 per cent of those practising OD were in just one country − India.
So water supply OK (unless you’re in rural Africa) but sanitation lamentably still not OK – no surprise there then.
Monday, 20 February 2012
India's 'tenacity' to beat polio
“India has become the latest nation to rid itself of polio with no new cases being reported since January 2011. 170 million children were immunised over the weekend in the biggest drive of its kind in the world.”
Political will has been the key −listen to this audioclip. We really need such will to be as effective in sanitation provision!
Political will has been the key −listen to this audioclip. We really need such will to be as effective in sanitation provision!
Friday, 10 February 2012
Anaerobic systems
I keep coming across more than quite a bit of confusion here! So let’s be clear. Septic tanks were first developed in France in the 1860s by Jean-Louis Mouras. Donald Cameron used them in England in 1895 (see his “Monster Septic Tank” here). What happened next? Well, Imhoff tanks came on the scene in 1906, though these were too big for individual use (prefabricated units are still available for up to 1000 p.e. − details here).
Quite a bit of research on septic tanks was done in the1950s by the US Department of Housing (important as around a third of US households are served by septic tanks) – the main emphasis was on how many compartments it should have. I’ve lost/can’t find most of these reports but my memory is that it was found that two compartments were better than one but that three weren’t better than two (nor were four or five, etc.).
Upflow filters were then developed in India to ‘polish’ septic tank effluents − see Upflow filters for septic tank effluents by V. Raman and N. Chakladar (Journal of the Water Pollution Control Federation 44 (8), 1552−1560, August 1972). I think these are excellent!
Then came the next septic-tank development: the UASB – upflow anaerobic sludge blanket reactor (developed by Professor Gatze Lettinga of Wageningen University in the 1970s): the influent is introduced across the reactor base and flows upwards, through the sludge layer, to the effluent weir; biogas can be collected if so desired. [Gatze Lettinga said to Barbara Evans, who works with me at Leeds, ‘why are you going to Leeds to work with Duncan Mara – he’s mad’. I take this as a compliment as I’ve “seen through” UASBs!]
A PhD student of mine, Professor Miguel Peña Varón, developed the high-rate anaerobic pond (HRAnP) to combine the efficiency of UASBs with the simplicity of anaerobic ponds (he also showed that conventional anaerobic ponds were ‘better’ than UASBs – see here).
Then came DEWATS − Decentralized Wastewater Treatment Systems – which typically comprise a ‘settler’ (a two-compartment septic tank) and an ‘anaerobic baffled reactor’ (ABR) (basically a baffled septic tank), followed by an anaerobic filter and a ‘planted gravel filter’ (i.e., a horizontal-flow constructed wetland). There’s the Decentralized Wastewater Treatment Systems (DEWATS) and Sanitation in Developing Countries - A Practical Guide which will set you back €48.75 plus postage (€12 outside Europe)!
On ABRs see The evaluation of the anaerobic baffled reactor for sanitation in dense peri-urban settlements, a WRC report dated 2006. Part of the report’s recommendations: “The ABR is able to provide better and more efficient treatment of wastewater than a septic tank. Therefore it is recommended that an ABR system can be used in any situation that is considered appropriate for a septic tank.” I don’t think I agree with this somewhat sweeping recommendation!
This is getting a bit too much into wastewater treatment (rather than sanitation per se), so why not have, for a small community a two-compartment septic tank (with the influent entering across the base of the first compartment), or for a larger community a high-rate anaerobic pond, then a secondary facultative pond + an aerated rock filter? Not sure I care much for UASBs, DEWATS or ABRs. Well, I thought I’d just mention it.
Quite a bit of research on septic tanks was done in the1950s by the US Department of Housing (important as around a third of US households are served by septic tanks) – the main emphasis was on how many compartments it should have. I’ve lost/can’t find most of these reports but my memory is that it was found that two compartments were better than one but that three weren’t better than two (nor were four or five, etc.).
Upflow filters were then developed in India to ‘polish’ septic tank effluents − see Upflow filters for septic tank effluents by V. Raman and N. Chakladar (Journal of the Water Pollution Control Federation 44 (8), 1552−1560, August 1972). I think these are excellent!
Then came the next septic-tank development: the UASB – upflow anaerobic sludge blanket reactor (developed by Professor Gatze Lettinga of Wageningen University in the 1970s): the influent is introduced across the reactor base and flows upwards, through the sludge layer, to the effluent weir; biogas can be collected if so desired. [Gatze Lettinga said to Barbara Evans, who works with me at Leeds, ‘why are you going to Leeds to work with Duncan Mara – he’s mad’. I take this as a compliment as I’ve “seen through” UASBs!]
A PhD student of mine, Professor Miguel Peña Varón, developed the high-rate anaerobic pond (HRAnP) to combine the efficiency of UASBs with the simplicity of anaerobic ponds (he also showed that conventional anaerobic ponds were ‘better’ than UASBs – see here).
Then came DEWATS − Decentralized Wastewater Treatment Systems – which typically comprise a ‘settler’ (a two-compartment septic tank) and an ‘anaerobic baffled reactor’ (ABR) (basically a baffled septic tank), followed by an anaerobic filter and a ‘planted gravel filter’ (i.e., a horizontal-flow constructed wetland). There’s the Decentralized Wastewater Treatment Systems (DEWATS) and Sanitation in Developing Countries - A Practical Guide which will set you back €48.75 plus postage (€12 outside Europe)!
On ABRs see The evaluation of the anaerobic baffled reactor for sanitation in dense peri-urban settlements, a WRC report dated 2006. Part of the report’s recommendations: “The ABR is able to provide better and more efficient treatment of wastewater than a septic tank. Therefore it is recommended that an ABR system can be used in any situation that is considered appropriate for a septic tank.” I don’t think I agree with this somewhat sweeping recommendation!
This is getting a bit too much into wastewater treatment (rather than sanitation per se), so why not have, for a small community a two-compartment septic tank (with the influent entering across the base of the first compartment), or for a larger community a high-rate anaerobic pond, then a secondary facultative pond + an aerated rock filter? Not sure I care much for UASBs, DEWATS or ABRs. Well, I thought I’d just mention it.
Tuesday, 24 January 2012
Research imperialism/nepotism
What on earth is “research imperialism”? It’s a phrase I use to describe the situation whereby a researcher from an industrialized country with his or her pockets full of research dollars says to a more impoverished researcher in a developing-country university “Come on, let’s research this, I’ve got the dollars, and the funds will cover a trip or two by you to my university”. This is OK, of course, if the research topic is of genuine interest to both parties, but not if it’s only of real interest to the industrialized-country researcher. However, the developing-country researcher might well be tempted to go along with it as it will most probably look pretty good on his or her c.v. and the trip to Europe or the USA (or wherever) would be pretty good too. Does research imperialism exist? You bet it does! Constructed wetlands in East Africa, for one.
Say No to research imperialism!
And what about what I call “research nepotism”? Possibly even worse than research imperialism, research nepotism is giving large chunks of research money to your mates – and this includes people like your PhD supervisor. Does this occur? You bet it does! [Does Bwana Bill know? Sijui.]
Say No to research nepotism!
Say No to research imperialism!
And what about what I call “research nepotism”? Possibly even worse than research imperialism, research nepotism is giving large chunks of research money to your mates – and this includes people like your PhD supervisor. Does this occur? You bet it does! [Does Bwana Bill know? Sijui.]
Say No to research nepotism!
Monday, 23 January 2012
Latrines more expensive than sewers!
I normally assume that low-cost sanitation technologies are cheaper than conventional sewerage. Not necessarily so, at least according to Sophie Trémolet’s presentation “Effective Public Finance for Sanitation: A study for WaterAid” presented at the IRC Symposium ‘Pumps, Pipes and Promises: Costs, Finances and Accountability for Sustainable WASH Services’ which was held in The Hague from 16−18 November 2010. Here’s part of what she said:
In Dar es Salaam, the Government chose to concentrate 99% of public funding on building network sewerage and sewage treatment facilities, even though these systems benefit only 10% and 3% of the city’s population, respectively. Household on-site sanitation receives very limited funding for software support[which is] provided in a decentralised and uncoordinated manner, with no evidence of impact. This results in an inequitable situation, as the costs to households of building and maintaining a latrine are about 2 to 3 times higher than those of a network connection [emphasis added]. Public funding for the sanitation sector in Dar es Salaam is therefore not effective, as it does not significantly increase coverage, achieve environmental results or improve public health.
So latrines can be more expensive than sewerage. Ain’t that really strange!
►All the presentations made at the IRC Symposium are available here. Quite a few are well worth reading, especially those on costs.
In Dar es Salaam, the Government chose to concentrate 99% of public funding on building network sewerage and sewage treatment facilities, even though these systems benefit only 10% and 3% of the city’s population, respectively. Household on-site sanitation receives very limited funding for software support[which is] provided in a decentralised and uncoordinated manner, with no evidence of impact. This results in an inequitable situation, as the costs to households of building and maintaining a latrine are about 2 to 3 times higher than those of a network connection [emphasis added]. Public funding for the sanitation sector in Dar es Salaam is therefore not effective, as it does not significantly increase coverage, achieve environmental results or improve public health.
So latrines can be more expensive than sewerage. Ain’t that really strange!
►All the presentations made at the IRC Symposium are available here. Quite a few are well worth reading, especially those on costs.
Right advice?
How do you know that you’re getting the right advice? EcoSan toilets? Arborloos? DEWATS? UASBs? Even simplified sewerage? Do you, can you, trust the person(s) giving you this advice? Well, there’s nothing like knowledge – at least the knowledge that you should query all advice given to you. If you don’t know all the sanitation alternatives in detail (where they’re appropriate, how to design them, how much they might cost), then you need to find out about them and then query the advice you’ve received – for example you could look at Urban sanitation planning: A technology check list for planners or Sanitation for a healthy nation: Sanitation technology options (DWAF, Government of South Africa, 2002) [there are, of course, other publications but these two are at least both concise and comprehensive].
Let’s make 2012 the Year Of Good Advice!
Let’s make 2012 the Year Of Good Advice!
Saturday, 21 January 2012
Sewer gradients 2
The Orangi Pilot Project (OPP) in Karachi, Pakistan is a very well known low-cost sewerage project, but what is not so well known perhaps is that the site gradients in Orangi were greater than the minimum required sewer gradient, so hydraulically at least the project was bound to succeed. However, when this low-cost sanitation technology was applied in other cities in Pakistan, problems occurred as the site gradients were lower than the minimum sewer gradients.
I remember, after I gave a talk on simplified sewerage some years ago at a WaterAid meeting in London, a young woman engineer from OPP came up to me and asked if I’d go to Karachi and teach OPP staff how to design sewers! Well, nothing came of that, other than a realisation on my part that sewer hydraulics are incredibly important – a fact that really needs to be more widely appreciated.
I remember, after I gave a talk on simplified sewerage some years ago at a WaterAid meeting in London, a young woman engineer from OPP came up to me and asked if I’d go to Karachi and teach OPP staff how to design sewers! Well, nothing came of that, other than a realisation on my part that sewer hydraulics are incredibly important – a fact that really needs to be more widely appreciated.
Thursday, 19 January 2012
Sewer gradients
I’ve been told that simplified sewerage projects haven’t worked well in Sub-Saharan Africa. Is this because they’ve been run by NGOs with little or no previous experience of sewerage? Possibly. Here’s a test for you: due to ground conditions you have to have a sewer gradient larger than 1 in 200. Would you go for 1 in 300 or 1 in 100? [Simple if you’re an engineer, but maybe not if you’re not?]
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