Untreated wastewater has implications for the health of both humans and ecosystems. In the seas and oceans, deoxygenated ‘dead zones’ caused by nutrient loading and the discharge of untreated wastewater are rapidly growing, affecting an estimated 245,000 sq km of marine ecosystems and affecting fisheries, livelihoods and food chains (UN- Water 2017). Freshwater ecosystems are also being impacted in similar ways. Waterborne illnesses from contaminated freshwater supplies and the degradation of freshwater systems have far-reaching implications for the well-being of communities and their livelihoods. The figure is a schematic diagram showing the key natural and anthropogenic factors responsible for water contamination.
From collection: Sanitation and Wastewater Atlas of Africa - Ecosystems