It is easy to take water for granted. Clean water comes out of a tap, we use the water and then ‘dirty’ water disappears down the drain. In this way, the water that leaves our homes, schools and workplaces is contaminated. For most European citizens, such waste water is collected, transported and then treated at an urban waste water treatment plant, to remove components harmful to the environment and human health, before the water is returned to nature (EEA, 2018). The importance of access to clean water and sanitation is embedded in Goal 6 of the United Nations’ Sustainable Development Goals (UN, n.d). Supplying clean water and collecting waste water has required huge investment across Europe in recent decades. In this briefing, we show that challenges to securing sustainable water in future, such as climate change, present new opportunities for resource efficiency and improved environmental protection.
Urban waste water treatment
For most European citizens, sewage from our toilets, sinks and washing machines goes down pipes to be treated, reducing disease-causing organisms and the nutrient load that would otherwise cause pollution and the proliferation of algae.
Waste water from households and industry creates significant pressure on the aquatic environment because of the loads of organic matter and nutrients it contains. If released into waterways, ammonia and natural processes break down organic matter in the water but can use up the oxygen, making the river uninhabitable for fish and invertebrates. Meanwhile, excess nutrients, such as nitrogen and phosphorus, can cause plants and algae to grow excessively, cutting out light and using up the oxygen in the water through respiration or when the plants decay (Picture 1). The widespread introduction of effective waste water treatment during the 20th century has greatly improved human health and environmental quality…read more
Fuente: www.eea.europa.eu