Periurban sanitation: what's the problem?

To meet the WHO/UNICEF target of ‘Water & Sanitation for All by 2025’ some 4.4 billion people will have to be provided with improved sanitation during 2001−2025, and around half of these are/will be in ‘urban’ areas – but in reality we are talking about periurban areas. Given that most population growth over the next few decades will occur in ‘urban’ (again, really periurban) areas of developing countries, periurban sanitation will have to become much more important than it already is. Our current focus is on achieving the sanitation target of the Millennium Development Goals, but these efforts will have to be doubled if we are to meet the WHO/UNICEF 2025 sanitation target in periurban areas, and then maintained for the next quarter century as we seek to meet the sanitation needs of the additional two billion or so people expected in periurban areas by 2050. So the Big Question is: How can we provide affordable sanitation to these very large numbers of poor people in periurban areas in developing countries? The answer to this question depends in part on the population density: at low population densities on-site sanitation systems are normally feasible, but (and as we have known since the early 1980s), even if there is sufficient space for them, they may not necessarily be the cheapest option (and, because we are attempting to serve poor and very poor people, we have to consider cost); and, of course, at high population densities on-site systems become infeasible as there is no space for them. In addition to being affordable, the chosen sanitation system has to be both socially acceptable and institutionally feasible. Consider the typical periurban situation: a high population density, one too high to permit on-site sanitation systems. What are the ‘best’ solutions for sanitation? If affordable, the system of choice would normally be simplified sewerage (also known as ‘condominial’ sewerage). With this sanitation system we should remember that in Natal in northeast Brazil, where it was developed in the early 1980s, it became cheaper than on-site sanitation at the relatively low population density of ~160 persons per ha, there were no connection charges and the monthly charge for the service was only USD 1.50; and that in Chisty Nagar in Orangi, Karachi, Pakistan, where Brazilian-style simplified sewerage was first installed in Asia in the mid-1980s, the residents obtained their water (only ~27 litres per person per day) from public standpipes, thus demonstrating that a plentiful on-plot water supply is not a sine qua non for the system. Simplified/condominial sewerage is one of the components of the very successful ‘Slum networking’ programme in India, and it has also been used in small villages in northeast Brazil. It is socioculturally very acceptable as it appears to its users to be similar to conventional sewerage, so their sanitation system is the ‘same’ as that enjoyed by the rich. It is also institutionally acceptable simply because it is a sewerage system and, as such, it can be readily understood and appreciated even by very conservative sewerage design engineers, especially when they realise that its hydraulic design is actually more rigorous than that used for conventional sewerage

Periurban sanitation: what's the problem?

To meet the WHO/UNICEF target of ‘Water & Sanitation for All by 2025’ some 4.4 billion people will have to be provided with improved sanitation during 2001−2025, and around half of these are/will be in ‘urban’ areas – but in reality we are talking about periurban areas. Given that most population growth over the next few decades will occur in ‘urban’ (again, really periurban) areas of developing countries, periurban sanitation will have to become much more important than it already is. Our current focus is on achieving the sanitation target of the Millennium Development Goals, but these efforts will have to be doubled if we are to meet the WHO/UNICEF 2025 sanitation target in periurban areas, and then maintained for the next quarter century as we seek to meet the sanitation needs of the additional two billion or so people expected in periurban areas by 2050. So the Big Question is: How can we provide affordable sanitation to these very large numbers of poor people in periurban areas in developing countries? The answer to this question depends in part on the population density: at low population densities on-site sanitation systems are normally feasible, but (and as we have known since the early 1980s), even if there is sufficient space for them, they may not necessarily be the cheapest option (and, because we are attempting to serve poor and very poor people, we have to consider cost); and, of course, at high population densities on-site systems become infeasible as there is no space for them. In addition to being affordable, the chosen sanitation system has to be both socially acceptable and institutionally feasible. Consider the typical periurban situation: a high population density, one too high to permit on-site sanitation systems. What are the ‘best’ solutions for sanitation? If affordable, the system of choice would normally be simplified sewerage (also known as ‘condominial’ sewerage). With this sanitation system we should remember that in Natal in northeast Brazil, where it was developed in the early 1980s, it became cheaper than on-site sanitation at the relatively low population density of ~160 persons per ha, there were no connection charges and the monthly charge for the service was only USD 1.50; and that in Chisty Nagar in Orangi, Karachi, Pakistan, where Brazilian-style simplified sewerage was first installed in Asia in the mid-1980s, the residents obtained their water (only ~27 litres per person per day) from public standpipes, thus demonstrating that a plentiful on-plot water supply is not a sine qua non for the system. Simplified/condominial sewerage is one of the components of the very successful ‘Slum networking’ programme in India, and it has also been used in small villages in northeast Brazil. It is socioculturally very acceptable as it appears to its users to be similar to conventional sewerage, so their sanitation system is the ‘same’ as that enjoyed by the rich. It is also institutionally acceptable simply because it is a sewerage system and, as such, it can be readily understood and appreciated even by very conservative sewerage design engineers, especially when they realise that its hydraulic design is actually more rigorous than that used for conventional sewerage

Access to Water in the Slums of the Developing World

The text and data in this publication may be reproduced as long as the source is cited. Reproductions for commercial purposes are forbiddenThe discussion reveals the failure of public policies as well as markets to provide satisfactory solutions to the problems of access to a safe, affordable and continuous water supply. In many countries, especially those in Sub-Saharan Africa, access to safe water through household connections declined in the 1990s. Achievements in access rates in many Asian and African economies are the due to widespread use of public water points such as public standpipes and kiosks. These sources are important, but doubtless the quality of access to water with these facilities is unsatisfactory since they involve greater effort by households, involving queuing, carrying water and lacking continuous access. A substantial proportion of urban dwellers in developing countries, especially in unplanned settlements, rely on a wide range of small-scale providers whose services are vital in the absence of alternatives. Their services, however, are often inferior to those provided by the formal network. Invariably, the water charges of alternative sources are higher than those for supply from the public network.Final Published versio

Sanitation options in rural and urban areas: best practices

Suitable low-cost sanitation systems for use in poor rural and urban areas are described. For dispersed rural areas Arborloos generally represent the ‘best’ choice. As the density increases other options may be used, including alternating twin-pit or twin-vault systems providing they can be desludged by the users. In poor urban areas the choice is normally between simplified sewerage, low-cost combined sewerage and community-managed sanitation blocks

THE EFFECTS OF CAP REFORM ON THE PERIURBAN AGRICULTURAL AREA IN THE PLAIN OF THE CITY OF ASSISI (CENTRAL ITALY)

In periurban areas agriculture can assume a multifunctional role that includes landscape conservation, sustainable resource management, biodiversity conservation, leisure activities, and can also maintain adequate conditions in densely populated areas for a safe and habitable environment. This study investigates the effects of the introduction of single farm payment on the periurban agricultural area in the plain of the City of Assisi, an area with a strong landscape value. A survey was carried out to determine: changes in production, changes on farm incomes, structural adjustments, the level of multifunctionality of periurban agriculture. Moreover, a survey of 355 residents was made to assess their willingness to pay for some positive externalities of the agriculture in this area. The results suggest the low-impact of reform on farms and the existence of a significant demand for environmental and social functions of the periurban agriculture of this region.Periurban Agriculture, Cap Reform, Economic Valuation, Contingent Valuation, Assisi, Agricultural and Food Policy, Research Methods/ Statistical Methods, Q10, Q18,

Planning approaches for sanitation systems in peri-urban areas: a case study from Tanzania

The planning and improvement of sanitation systems represents a critical problem for low - income countries, in particular in rapid growing periurban areas. This paper illustrates the assessment of the Community - Led Urban Environmental Sanitation (CLUES) and the Sanitation Safety Planning (SSP) approaches, tested for the design of an improved sanitation system in periurban areas of Iringa Municipality, in Tanzania. The application in field of the two approaches permitted to evidence and analyse their strengths and weaknesses, and possibilities to increase their potentials with an integrated use . The experience, applied to a case study, aims to be an example of application for ractitioners dealing with sanitation planning in context showing similar characteristics

Access to Water in the Slums of the Developing World

According to the United Nations Human Settlements Programme (UN-Habitat), 924 million people lived in slums in 2001. Population growth in these settlements is much greater than in other urban areas. The estimates suggest that this figure may rise to 1.5 billion by 2020 (Payne, 2005). This rapid increase is expected despite ?slum upgrading? efforts that have been taking place for decades, though inconsistently and with disruptions over time. There is a prolific literature on informal settlement areas, but research on access to essential services such as water and sanitation (WS) in these areas is very limited. Most studies consider issues of access in connection to urban poverty, an approach that often reduces the discussion to the income and expenditure constraints faced by households. Examining access to WS in the slums spurs an appreciation of the multidimensional nature of the problem, including income poverty, infrastructural limitations, asset ownership and housing quality. Moreover, developments in the slums concern every aspect of the Millennium Development Goals (MDGs). This paper examines the conditions of access to water in the slums of the developing world. It has three goals. The first is to identify the objective and policy-related challenges that hinder progress in the provision of safe, affordable, continuous and easy access to water in countries where there is a sizeable slum population. The second is to explore the existing systems of provision in informal settlements and to discuss the weaknesses and strengths of each. The third is to make policy recommendations. Though the discussion on access to sanitation is limited, this is not to deny the importance of that issue. Besides, water and sanitation services are often intrinsically linked and therefore are provided together by network utilities. The discussion reveals the failure of public policies as well as markets to provide satisfactory solutions to the problems of access to a safe, affordable and continuous water supply. In many countries, especially those in Sub-Saharan Africa, access to safe water through household connections declined in the 1990s. Achievements in access rates in many Asian and African economies are the due to widespread use of public water points such as public standpipes and kiosks. These sources are important, but doubtless the quality of access to water with these facilities is unsatisfactory since they involve greater effort by households, involving queuing, carrying water and lacking continuous access. A substantial proportion of urban dwellers in developing countries, especially in unplanned settlements, rely on a wide range of small-scale providers whose services are vital in the absence of alternatives. Their services, however, are often inferior to those provided by the formal network. Invariably, the water charges of alternative sources are higher than those for supply from the public network. Section 2 provides a general discussion of informal settlements and outlines the growth of slum development and trends in access to water supply since 1990. Section 3 examines changing public policies towards squatter settlements and the challenges such settlements pose. Section 4 presents the problems associated with the existing market-based water supply arrangements in countries where a sizeable proportion of the urban population resides in informal settlement areas. We then argue for the need to pursue a more proactive public policy on the basis of a discussion that highlights the limitations of private sector ventures. The paper concludes with a number of policy recommendations.Access to Water in the Slums of the Developing World

Mikrosporidien des Eichenprozessionsspinners, Thaumetopoea processionea (L.) (Lep., Thaumetopoeidae) in den Eichenwäldern Ostösterreichs

Since the late 1990s, the oak processionary moth, Thaumetopoea processionea (L.), has been occurring at high population densities in eastern Austria. Particularly, infestations in areas of human settlement have created increasing interest in this insect due to health problems caused by the urticating hairs of the larvae. New methods for biological control are desirable. Like essentially all forest Lepidoptera, T. processionea is host for entomopathogenic microsporidia. These obligatory parasitic protists have been evaluated as biocontrol agents against an other oak pest, Lymantria dispar (Weiser & Novotny, 1987; Jeffords & al., 1988). Life history traits of T. processionea make this insect an even more promising target for the use of microsporidia. The larvae are highly gregarious and stay together in nests made of larval silk for resting periods and molting. Microsporidia utilize several pathways for horizontal transmission that would be aided by these features: spores can be released after host death from cadavers as well as from living larvae via silk or feces. Additionally, many microsporidia are vertically transmitted (summarized in Maddox & al., 1998). In this project, T. processionea larvae from various regions in eastern Austria were screened for the natural occurrence of microsporidia. One isolate, Endoreticulatus sp., was further studied and mass produced in a laboratory host, L. dispar, that is easy to rear and does not pose a health hazard for people working with the insects. An inoculative release was attempted on isolated trees infested with T. processionea.In einem zweijährigen Screening untersuchten wir das Auftreten von Mikrosporidien bei Thaumetopoea processionea an verschiedenen Standorten in Ostösterreich. In neun von 18 Populationen wurden Mikrosporidiosen nachgewiesen, die Prävalenzen lagen zwischen 1,9 % und 15,4 %. Basierend auf lichtmikroskopischen Befunden waren die gefundenen Pathogene den Gattungen Endoreticulatus, Nosema, Cystosporogenes und Vairimorpha zuzuordnen. Endoreticulatus sp. vermochte im Labor Raupen von Lymantria dispar zu infizieren. Das erlaubte die einfache Produktion von Inokulum sowie Untersuchungen mit einem ungefährlichen Wirtsinsekt. Laborversuche mit L. dispar zeigten einen langsamen Krankheitsverlauf, der aber in signifikant erhöhter Mortalität resultierte (nur 26 % der oral inokulierten Tiere entwickelten sich zu Imagines), sowie eine effiziente horizontale Übertragung. Eine inokulative Freilassung wurde versucht: dazu wurden Endoreticulatus-Sporen in wässriger Suspension auf Blätter isoliert stehender, von T. processionea befallenen Eichen ausgebracht. Die Inokulation war erfolgreich, allerdings auf niedrigem Niveau – die maximale Infektionsrate lag bei 9,5 %