veesaaste

Veesaaste is contamination of water bodies that degrades water quality and harms ecosystems and human uses. It encompasses chemical, physical, and biological pollutants that enter rivers, lakes, and coastal waters. Common sources include point sources such as industrial discharges and municipal wastewater, and non-point sources such as agricultural runoff, stormwater, and sediment erosion. Contaminants include nutrients (nitrogen and phosphorus), pesticides, heavy metals, organic chemicals, microplastics, pathogens, and emerging contaminants such as pharmaceuticals.

Effects include eutrophication, hypoxia, loss of biodiversity, harmful algal blooms, taste and odor problems, corrosion of infrastructure, and health risks for drinking water and recreation.

Monitoring and assessment are conducted by measuring water quality against standards and by using biological and chemical indicators. In the European Union, the Water Framework Directive provides the framework for achieving good status of surface and ground waters. Finland, like other member states, implements national programs through agencies such as the Finnish Environment Institute (SYKE) and regional authorities, with classified statuses for water bodies.

Prevention and mitigation focus on reducing inputs at the source, improving wastewater treatment, optimizing agricultural practices to limit nutrient runoff, and using green infrastructure to manage stormwater. International cooperation is important for transboundary water bodies, such as the Baltic Sea, where veesaaste from multiple countries contributes to regional pollution.