In most high density urban areas in developing countries sewerage based excreta disposal systems are the rare exception. Even where sewers are present, high connection charges often exclude the poor. An on-site latrine is the most common form of sanitation but often both the people who use them and the technology are ignored or marginalised within any plans to improve a city’s sanitation.
Defecating in a plastic bag in the privacy of your own home and then dumping it on a waste pile or throwing it as far as possible (hence the name ‘flying toilet’) may sound a fairly basic form of behaviour but it is cheap, does not take up a lot of space, is discrete, and is better than the alternative of defecating directly on to the waste pile in public. It is a behaviour most occupants of the high density slum areas would find disgusting and embarrassing but it is a rational solution to a chronic problem. This same rationalism is demonstrated by the way an elderly lady in a Kampala slum described how she and her family used the communal latrine. The latrine is only 200m from her house and she was happy to use it during the day but at night the prospect of using three unstable plank bridges to cross over filthy drains, navigating around piles of vermin infested solid waste, plus the high risk of robbery and rape, means that using the communal latrine is irrational; “Where would you go at night?” she asked.

As a generalisation, demand for latrines in densely populated areas is high and the constraints relate to space, affordability, limited design choice, lack of a permanent solution (linked to a lack of pit emptying services), land tenure and landlords not meeting their responsibilities. These vary in relevance from site to site and sanitation programmes should be aiming to assist house owners overcome these constraints and make latrine ownership possible, affordable and the rational choice.

The lack of planning controls in ‘unplanned’ areas and the subsequent increasing housing density has two detrimental impacts to the development of sustainable excreta management:

• streets and passages become narrower making access for vacuum tankers that empty pits increasing difficult.
• average compound sizes decrease as plots are continually divided to build more and more houses. The space available to build an initial or replacement latrine eventually diminishes to such an extent that erecting the traditional style of building is impossible.

Projects aimed at building latrines, particularly ones with large standard designs ignore these constraints and are unlikely to have much long term impact. The key questions that need to be addressed are:

• how will householders empty their pit once it is full?
• what designs present good value for money and have the attributes desired by the residents?
• what can people afford? Alternatively can credit be provided to make purchasing a latrine suit their cash flow constraints?
• how can tenants be best served or how can pressure be placed on landlords to provide facilities?
• how can the commercial viability of the provision of services and products be maximised?
• how can latrine designs be made more environmentally friendly?

These questions move the designer beyond simple product provision to sustainable service delivery which, like a sewage service, needs continuous management, institutionalised structures of responsibility, and on-going resources. The solutions lay in the development of product-service packages where the design of emptying services compliments the design of the latrine and vice-versa. A clear distinction needs to be made between where private householders’ responsibilities stop and public responsibilities start. This is taken up in the next section on partnerships. In practice excreta management has more in common with solid waste management and brings into question why sanitation is always linked to water supply.

An important and sensitive question relating to urban public private partnerships is that of the divide between public and private responsibility. With sewered systems (that mainly serve the rich) public funds are used to install, manage and maintain public sewers and tariffs or taxation is used to recover costs. No such publicly funded services are provided for the poor living in the unplanned high density areas and excreta disposal is regarded as being the sole responsibility of the household. This is legally and morally incorrect. Government support should benefit the poor as least as much as the rich. If the same principle were to be applied to high density areas, the pit emptying process would be established through public finance and waste would be collected from the threshold of the house. Cost recovery could occur through a form of volumetric tariff. Unfortunately excreta disposal for the poor is largely ignored and any services that have been established will be privately financed and informally organised. Such services will likely be unregulated and have weak links with the public sector, even though they provide an important public service. It is arguable that the public health benefits from providing a pit emptying service could be so great that it warrants to be totally public funded and provided free of charge to the poor. In practice such services are very rare because of the inability of the (often informal) small scale providers to make pit emptying a commercially viable service.

From a legislative point of view, Governments may also be failing to fulfil a statutory duty. For example in Dar es Salaam, Tanzania, the Local Government (Urban Authorities) Act 1982 states in Section 53:

“It shall be the duty of every urban authority to discharge the function conferred upon it by this act …..
(g) to maintain in good order and repair all public latrines, urinals, cesspools, rubbish bins … and provide for the removal of night soil and the disposal of sewerage from all premises and houses in its area, so as to prevent injury to health.”

In Dar es Salaam the Municipalities are currently not providing, or ensuring the provision, of a night soil removal service.