• Water supply
• Sanitation and hygiene
• Monitoring
• Cross-cutting issues

• Technical briefs

The WELL Guiding Principles are set out in the DFID Guidance Manual on Water Supply and Sanitation Programmes, prepared by WELL in 1998. They are as follows:

• People matter more than science
• Software and hardware must go hand in hand
• Both public and private aspects of environmental health count
• Environmental infrastructure is about more than health

People matter more than science

Failures in environmental health in developing countries are usually human problems of conflicting interests, inadequate human resource development, or an inaccurate interpretation of the needs and priorities of various stakeholders. Whether or not technology and hygiene are promoted effectively has far more to do with specific institutional players and interest groups and their interaction than with medical or technical understanding. Despite lip service to gender awareness, all too often the perspectives and roles of women are ignored or undervalued. We need to understand demand for services from women, men, and children across all social groups before selecting suitable approaches and technologies.

Software and hardware must go hand in hand

Many public health engineering projects fail because the hardware has been provided, but the means to sustain the intervention beyond construction have not been developed. An integrated approach is required to develop suitable infrastructure by integrating the social, health, technical, economic, financial, institutional, and environmental aspects and planning for sustainable management, operation, and maintenance. The many demands on the time of both female and male residents severely constrain what is sometimes naively viewed as the limitless potential of community management. We also know that efforts to improve hygiene are futile where the basic requirements of water, sanitation, or drainage cannot be met.

Both public and private aspects of environmental health count

Environmental health services often require both centralized resources (e.g. water treatment works, trunk sewers, landfills) and distributed resources (e.g. local public taps, house drains and street sewers, pit latrines, and street-level solid waste collection). In addition, both public and private environments play distinct roles in disease transmission. In times of structural adjustment, public authorities have learned that they cannot manage both central and distributed resources, and that there are benefits in devolving responsibility for the distributed resources to local communities. Such an approach can improve cost recovery and accountability to local residents, while reducing total cost.

Environmental infrastructure is about more than health.

While improved health may be a project goal for infrastructural or environmental projects, it is not often a useful or complete indicator of success. On scores of occasions, water and sanitation projects have commissioned epidemiological or demographic evaluations of health benefits. Experience shows that, while fascinating for academic researchers, such studies are time-consuming, expensive, fraught with methodological defects, and frequently produce misleading or ambiguous results. Moreover, they do not help to diagnose the weaknesses of a project, or suggest ways in which its impact may be strengthened. Operational evaluations of facility functioning and consumer use, combined with studies of hygiene behaviour, are far more useful. Such studies can also illustrate other benefits of water and sanitation that are valued highly by the users, such as saved time, convenience, cost, and dignity, which are all too lightly dismissed in a narrow medical framework.