Once water is contaminated, it is difficult, costly, and often impossible to remove the pollutants. Still today, 80 per cent of global wastewater goes untreated, containing everything from human waste to highly toxic industrial discharges. The nature and amount of pollutants in freshwater determines the suitability of water for many human uses such as drinking, bathing, and agriculture. In addition, pollution of freshwater ecosystems can impact the habitat and quality of life of fish and other wildlife.
Pollution in freshwater ecosystems can include pathogens (largely from human and animal waste), organic matter (including plant nutrients from agricultural run-off such as nitrogen or phosphorus), chemical pollution and salinity (from irrigation, domestic wastewater and runoff of mines into rivers). Plastic pollution, and emerging pollutants such as pharmaceuticals, also increasingly put our world’s waterways at risk, but the extent and impacts of their presence in our freshwater is largely unknown.
A 2016 preliminary assessment of the water quality situation in rivers in Latin America, Africa and Asia, A Snapshot of the World’s Water Quality, estimates that severe pathogenic pollution affects around one third of all rivers, severe organic pollution around one seventh of all rivers, and severe and moderate salinity pollution around one-tenth of all rivers in these regions.
What we do
The Global Programme of Action for the Protection of the Marine Environment from Land-based Activity concentrates on the regulation and reduction of wastewater, marine litter and nutrient loading.
The GEMS/Water programme supports countries in monitoring and reporting on water quality.
UN Environment promotes nature-based solutions to water resources management, including for water quality, and is contributing to the topic for the 2018 World Water Day and 2018 World Water Development Report, coordinated by UNESCO WWAP (World Water Assessment Programme).
UN Environment is also the global custodian of Sustainable Development Goal (SDG) target 6.3.2, helping countries understand, measure and report on ambient water quality.