This policy brief, published by the Global Water Partnership, highlights the need to integrate wastewater into water resources management.
Better management of wastewater can help tackle water scarcity and pollution, says the author. This requires an integrated approach that encompasses the whole water cycle, from the available water resources to treatment and reuse.
Few developing countries treat wastewater — only one per cent of wastewater from households and industry in Africa is treated — but many do reuse it, most commonly for irrigation.
However although this practice can increase crop yields and farmer incomes, it carries significant environmental and public health risks — including groundwater contamination and increased incidence of diarrhoeal disease — unless accompanied by effective treatment and regulation.
When designing treatment plants, all the potential options for reusing wastewater should be considered and corresponding standards defined. The standard of water needed as an industrial coolant, for example, may differ significantly from that required for agricultural irrigation or aquaculture.
Treatment should also be planned close to reuse sites to be most cost-effective. And the choice of system should take into account local capacities for operation and maintenance. For example, decentralised systems may better protect watersheds and be more cost-effective if they avoid transporting wastewater over long distances.
The author makes several policy recommendations to encourage water reuse. These include strengthening political support by quantifying the benefits of reuse, improving public support by defining rights to wastewater and implementing public outreach and education programmes, and encouraging stakeholder participation through open discussions and participatory technology development.
Policymakers should also implement economic incentives such as lower prices and subsidies for wastewater, establish implementable guidelines for treatment and reuse, and facilitate cooperation among agencies and sectors such as health, municipal wastewater treatment and irrigation water distribution.