Water purity and sustainable water treatment systems for developing countries

International efforts to improve access to drinking water in developing countries have been successful over recent decades, but in 2020, over 2 billion people still lacked access to a safe and reliable water supply. Significantly greater challenges to improving access to safe water are now present, most notably the impacts of climate change and environmental degradation on the quality and quantity of fresh water supplies. Many developing countries face severe water stress, with increasing demand and aging water infrastructure failing to meet requirements in urban and rural areas. Deteriorating water quality and supply are also likely to necessitate more sophisticated water treatment methods in the long-term, which will significantly impact developing countries that have limited resources to allocate to water management and where water treatment systems are often basic. These new challenges arise in the context of many countries already operating below WHO-recommended quality guidelines for drinking water supply. Sustainable water treatment and water management systems are urgently needed to address the particular needs of developing countries, who will feel the effects of climate change most severely due to vulnerable geography and poor capacity to cope with deteriorating water supplies and damage from severe weather and rising sea levels. Local water sources including wastewaters such as greywater and rainwater can form part of sustainable water supply solutions. Resourcing and supporting community management systems and other decentralized water management models will improve the sustainability of water interventions, particularly in rural areas where premature system failure is frequent. Increased collaboration in terms of resilient technology and systems is needed between developed and developing countries to address the urgent challenges of the 21st century.