
Ceramic water filters (CWF) are an inexpensive and effective type of water filter that rely on the small pore size of ceramic material to filter dirt, debris, and bacteria out of water. This makes them ideal for use in developing countries, and portable ceramic filters are commonly used in backpacking.

Failures of water supply and sanitation systems describe situations where water supply and sanitation systems have been put in place (for example by the government or by non-government organizations but have failed to meet the expected outcomes. Often this is due to poor planning, lack of choice of appropriate technology depending upon the context, insufficient stakeholder involvement at the various stages of the project and lack of maintenance. While Hygiene Behavior Change is important in achieving the health benefits of improved WASH systems, the achievement of sustainability of WASH infrastructure depends on creation of demand for sanitation services.

Laos is a nation with plentiful surface water and broad rivers, but outside of cities there is little infrastructure to make that water clean and accessible. Very little improvement has been made since the end of the Laotian Civil War in 1975, especially compared to peer nations such as Thailand. By 2015, 76% of Laotians nationwide were estimated to have access to “improved” water, while 71% were estimated to have access to “improved” sanitation.

Water supply and sanitation in Latin America is characterized by insufficient access and in many cases by poor service quality, with detrimental impacts on public health. Water and sanitation services are provided by a vast array of mostly local service providers under an often fragmented policy and regulatory framework. Financing of water and sanitation remains a serious challenge.

This is a list of countries by the proportion of their population using improved sanitation facilities.

WASH is an acronym that stands for "water, sanitation and hygiene". Universal, affordable and sustainable access to WASH is a key public health issue within international development and is the focus of the first two targets of Sustainable Development Goal 6. Targets 6.1 and 6.2 aim at equitable and accessible water and sanitation for all. "Access to WASH" includes safe water, adequate sanitation and hygiene education. Improving access to WASH services can improve health, life expectancy, student learning, gender equality, and other important issues of international development. This can reduce illness and death, and also affect poverty reduction and socio-economic development. Challenges include providing services to urban slums, improper management of water distribution systems, failures of WASH systems over time, providing equitable access to drinking water supply and gender issues. WASH services have to be provided to household locations but also to schools, healthcare facilities, work places, markets, prisons, train stations, public locations etc.

Wastewater treatment is a process used to remove contaminants from wastewater or sewage and convert it into an effluent that can be returned to the water cycle with acceptable impact on the environment, or reused for various purposes. The treatment process takes place in a wastewater treatment plant (WWTP), also referred to as a Water Resource Recovery Facility (WRRF) or a Sewage Treatment Plant (STP) in the case of domestic wastewater. Pollutants in wastewater are removed, converted or broken down during the treatment process.

Although access to water supply and sanitation in Sub-Saharan Africa has been steadily improving over the last two decades, the region still lags behind all other developing regions. Access to improved water supply had increased from 49% in 1990 to 68% in 2015, while access to improved sanitation had only risen from 28% to 31% in that same period. Sub-Saharan Africa did not meet the Millennium Development Goals of halving the share of the population without access to safe drinking water and sanitation between 1990 and 2015. There still exists large disparities among Sub-Saharan African countries, and between the urban and rural areas. The MDGs set International targets to reduce inadequate Water Sanitation and Hygiene (WASH) coverage and now new targets exist under the Sustainable Development Goals. The MDGs called for halving the proportion of the population without access to adequate water and sanitation, whereas the SDGs call for universal access, require the progressive reduction of inequalities, and include hygiene in addition to water and sanitation. Particularly, Sustainable Development Goal SDG6 focuses on ensuring availability and sustainable management of water and sanitation for all.