Executive Summary
Updated - Wednesday 19 November 2003
Developing countries are facing a rapid urban growth with an increasing demand for urban infrastructure services. The resources needed for these services are being stretched to their limit, which results in deterioration of the quality and adequacy of the infrastructure, particularly in low-income residential areas.
One of the basic services which suffers most from the budgetary constraints is the disposal of human excreta. This has led many governments to adopt low-cost technologies, which are cheaper to construct and require less water for functioning. To a large extent operation and maintenance of these systems can be carried out by the users, with the government responsible for the infrastructure to evacuate the waste beyond the household premises.
Over the last decade, problems have been experienced with these systems. Many have fallen into disuse for reason of early failure and/or misuse. This resulted in a lower service level to the target population and a consequent deterioration of the urban environment. Studies, which have been looking to these systems, have mainly focused on technical and financial aspects of the problem. The other aspects such as the actual use of the different technical options, the occurring problems and their possible causes, have not yet been investigated in a systematic way. In Thailand and India, this was the reason to initiate a study on aspects of operation and maintenance of sanitation systems in low-income urban areas, needed for the planning and design of future systems.
The study
The objectives of the study are to review the performance, use and operation and maintenance requirements of sanitation systems in low-income urban areas in India and Thailand. Specific attention is given to user attitudes and practices with regard to operation and maintenance of the systems and to the role of the authorities both in the provision of the systems and in their operation and maintenance. The outcome of the study includes an assessment of the requirements for operation and maintenance and recommendations for the planning, design, implementation and management of future sanitation schemes.
The research focuses particularly on the systems in which the participating institutions in the countries have an interest. For the Human Settlement Management Institute in India this is the double pit pour-flush latrine. For the National Housing Authority and the Chiang Mai University in Thailand, these are the cesspool system, the septic tank with anaerobic upflow filter and two types of treatment plants, the aerated lagoon system and the activated sludge system-aeration tank. Other systems found in the research areas are also included in the analysis, such as public latrines in India and septic tanks with soakaway in Thailand.
Major findings
In the research areas in India, the performance of the double pit pour-flush latrines is generally quite good. Technical problems are to a large extent related to indiscriminate use of a standardized design, without paying attention to soil conditions, groundwater table and the availability of water. Experiments with locally available construction materials to reduce construction cost are not attempted. The research showed that the capacity of the pits is very large as 70 percent of the first pit had not filled after five or more years. The quality of construction of the latrines is usually adequate, only the cover and alignment of the junction boxes require more attention. Daily operation and maintenance of the latrines does not pose any problem for the users, but awareness on the functioning of the system and on the longer term operational requirements is lacking as a result of insufficient instruction.
A serious problem encountered is the non-use of the latrines. An important reason for this appears to be that the latrines are usually promoted through a system of grants and loans and not based on demand from the users. Where superstructures are provided with the latrine, the latrine is often used for other purposes and where they are not provided, people are reluctant to construct them. An approach where the community and the beneficiaries are involved in planning and implementation and awareness and motivation campaigns are carried out, is seldom used although it leads to much better results.
Local authorities are rarely involved in planning and implementation of the sanitation schemes, although they have the responsibility to motivate the beneficiaries, to provide services for operation and maintenance and to collect loan repayments. As a result, technical knowledge on the systems is insufficient and interest in providing services for operation and maintenance is lacking. There is no budget or strategy for services for operation and maintenance. Loan repayment is often not organized or pursued.
On the other hand, the authorities at national and state level who carry out planning and design and supervise implementation, are never responsible for operation and maintenance and are insufficient aware of the operation and maintenance requirements. This is for instance reflected in the selection of contractors and the determination of unit cost at state level and the lack of capacity building at local level.
In Thailand the research is carried out in slums and in housing projects of the National Housing Authority. All households have and use a toilet. Technical problems mainly relate to environmental pollution and health risks. People in slum areas which are flooded adapt their cesspools by making holes in the concrete rings. This results in raw sewage leaking in the standing water. The septic tank with anaerobic upflow filter as constructed by the NHA in two research areas does not function well and people find backwashing of the filter a dirty job to do. As a consequence, the anaerobic upflow filter is often bypassed causing black water to enter the sewerage system, for which the main treatment system is not designed. Location and type of sanitation system in the NHA projects does not meet users' preferences, resulting in private construction of new latrines. Awareness of health aspects and environmental pollution is largely lacking and people are generally happy with their toilets.
The on-site systems have to be desludged, which is sometimes a problem because adapted technologies for desludging in slums and low-income housing areas with small roads are not existing. Desludging services in the North of Thailand are privatized under control of the municipal authorities. This system is very efficient. In Bangkok the only legal desludging services are rendered by the BMA at very high cost. However, they only collect about a third of the waste produced, the rest is illegally collected by private agencies and disappearing in the environment.
The sewer systems taking sewage from the houses to the treatment plants are not functioning well. Due to soil inclination, many sewers are cracked and connections between branch and main sewers are broken, impeding the flow of sewerage. The sewers are full of sand and sewage leaks out. The sewers are difficult to clean not only because of the soil inclination, but also because the distance in manholes is too large and one of the systems requires equipment for cleaning which is not easily available. In one area, the treatment plant cannot function properly because only an estimated 60-80 percent of the total volume of sewerage reaches the plant. The other plant functions reasonable well, but close monitoring is needed to establish the capacity of aerators needed for sufficient aeration.
In all NHA projects there are estate management offices located, amongst others responsible for operation and maintenance services. Due to insufficient training, technical assistance to the households is practical rather than environmentally sound. Feedback from the estate offices on experiences with operation and maintenance of the installed systems to the planning and design departments of NHA is insufficient.
In the NHA projects there is no separate budget for operation and maintenance of the sewerage and treatment plants, which results in the saving of expenses on operation and maintenance in favour of other tasks. The operation and maintenance of the main sewers and treatment plants was recently handed over by the NHA to the Bangkok Metropolitan Administration (BMA). This transfer was not without problems because the requirements and cost for operation and maintenance were not sufficiently clear, while the systems were already deteriorating. Moreover, BMA was not involved in the planning, design and construction of the sewers and plants and is therefore not able to adapt the systems to its technical and financial capacity.
Main lessons learned
Low-cost sanitation systems offer a viable solution for the safe disposal of human waste in low-income areas provided that requirements for operation and maintenance are taken into account from the start. Proper operation and maintenance depends on integrating its requirements in planning, design, implementation and management in which coordination between government, private agencies and residents is essential.
Laws and regulations, standardized procedures and technical designs are important for operation and maintenance. But actual decisions on the most suitable type of sanitation system and on the organization and management of operation and maintenance should always be based on local conditions, both with respect to technical and socio-economic feasibility and to users' preferences and capabilities.
Operation and maintenance require a sound organization and clear responsibilities. During planning and design, division of responsibilities and definition of tasks and accountability require ample consideration and agreement between parties concerned. Creating conditions in which responsibilities can be implemented as intended requires awareness raising, motivation, training and incentives both in the agencies and with the users.
A separate budget for operation and maintenance is required, not only to cover regular operation and maintenance, but also to allow for replacement and rehabilitation. A separate budget is necessary to avoid diversion of funds for operation and maintenance for other purposes in a situation where municipalities are perpetually short of funds.
Environmental pollution, as a consequence of private adaptations to sanitation systems and deterioration of existing systems due to neglect of maintenance, needs special attention. Although laws and regulations exist to protect the environment, they can only be effective if they are actively implemented.
These main conclusions confirm a number of known problems in operation and maintenance and show how difficult it is to apply available knowledge and experience in practice. They further emphasize the critical importance of a functional integration of requirements for operation and maintenance in all phases of the provision of sanitation systems in low-income urban areas, right from the planning and design phase.
