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 Framework for Wastewater and Stormwater Management Technology and technology selection, though very important, cannot be detached from other equally important factors for its successful implementation. A framework is required that considers the concept of integrated waste management, the cross cutting issues and involvement of all the stakeholders. Integrated waste management Simply solving the problem of wastewater without taking into account of solid wastes and stormwater will not achieve sufficient improvement to protect public health and the environment. An integrated approach considering the three is required (Figure 1). This approach requires that the three wastes should not be mixed. Solid wastes should not be dumped into stormwater drains, but should be collected, recycled, reused, or treated and disposed separately. Dumping of solid wastes in stormwater drains will not only restrict the flow of stormwater, they contaminate stormwater. Treatment of the stormwater will involve separating the solids and other contaminants from the water. Similarly industrial wastes should be treated separately.
Another useful tool that can help towards achieving integrated waste management is the waste management hierarchy. The waste management hierarchy in its most general form is shown in Table 1. In using this tool for waste management we systematically go down the list to see if step 1 (Prevent or reduce waste generation) can be implemented, before considering the next step (2) and so on. Only when steps (1) to (5) have been fully considered that we consider disposal of the waste (step 6).
Cross-cutting issues Besides the public health and environmental aspects discussed under integrated waste management, there are the social and institutional dimensions that have to be taken into account. The issues associated with how communities manage their common endeavour, which in our case is managing wastewater and stormwater, are termed "cross-cutting" issues. Planning, community participation and financial aspects are discussed in some detail in the Source Book (Figure 2). These and other issues are elaborated further and addressed in a complementary publication by UNEP GPA "Guidance on Municipal Wastewater"
Settlement planning Planning appears to be a major and key issue for a community to address. Ideally settlements should be planned ahead of their occupation. Areas should be set aside for treatment and disposal of solid wastes which cannot be recycled or reused. Easement should be provided in the plan if wastewater is to be collected through a sewerage system, or if on-site treatment is chosen, lot sizes should be adequate to accommodate the treatment system. Planning should also take into account the natural drainage of the landscape to enable stormwater run-off to flow freely by gravity and minimise flooding. Water reuse should also be carefully planned. Generally a sufficient area must be set aside for water reuse, which can take the form of water for agriculture, aquaculture, tree plantation or for irrigation of public parks and gardens. Planning to achieve long term resource sustainability and to deal with rapid urbanisation are two aspects which demand special attention. Community participation and hygiene promotion Much has been said about the need to involve the whole community in provision of sanitation services to ensure that any service that is provided is what the community wants. This will help ensure the viability of the service and its long-term sustainability. The need to involve women has been emphasised, because women are generally responsible for the day-to-day management of wastes at the household level. How far community participation can be implemented depends on the social, cultural and political practices within the community. The decisions taken by a community are influenced by its knowledge base. One aspect that may be lacking is the awareness of the relationship between illnesses and lack of hygiene and sanitation. This may be reflected in the low priority given to provision of sanitation services. Promotion of hygiene is therefore an important issue that has to be addressed. The promotion materials should include not only the relationship between health and sanitation services, but also the correct choice of sanitation hardware, and in its maintenance and operation. Financing of sanitation services and cost recovery Sanitation services require investment and continuing costs of operation and maintenance. The level of investment is dependent on the technology that is chosen. The technology also determines the costs associated with its operation and maintenance. A community may be able to provide in-kind contribution such as labour towards the construction of a wastewater collection system. With a simple on-site wastewater system the community may be able to do most of its construction. Knowledge of technology options is therefore essential to a community to decide which one to choose, because in the end they have to pay for both the investment and operating costs if the service is to be sustainable in the long term.
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