The cleanest rivers and lakes in Europe, Switzerland

Problems

• Cleaning rivers and lakes from medical and chemical waste in Switzerland

  Situated at the hydrographic center of Europe, Switzerland is the source of many major rivers. 
  The two most important are the Rhône, which flows into the Mediterranean Sea, and the Rhine, which empties into the North Sea.
  
  Lakes, large and small, are an important source of water, recreational opportunities, and suitable habitat for fish-eating birds.
  
  The two largest lakes, Lake Geneva and Lake Constance are among the largest in Europe. The largest entirely Swiss lake is Lake Neuchâtel. The others are Lake Maggiore and Lake Lucerne. There are a total of 103 lakes with a surface area greater than 30 hectares and a significant number of smaller lakes.
  
  Up until the 1950s, waste was dumped directly into Swiss rivers and lakes, resulting in dying fish, bad smells and swimming bans. 
  
  About 15% of the Swiss population was connected to a wastewater treatment plant. Wastewater often flowed directly into rivers and lakes. Even commercial and industrial wastewater containing toxic substances is used to go untreated into the waters. 
  
  A key driver of that transformation was a tragedy in the mountain resort of Zermatt in 1963, when a typhoid outbreak killed three people and made 437 others ill. Soldiers were deployed and schools turned into emergency hospitals as panic spread. 
  
  Pressure grew on the government to clean up the waterways, found to be the source of the outbreak. In 1971, the treatment of wastewater was written into Swiss law.
  
  Micropollutants such as drug residues, pesticides, chemicals and hormones are harming animals and plants. However, sewage treatment plants cannot filter them out. The products can lead to organ damage and sterility in fish, for example. 
  
  Switzerland became the first country to enforce legislation to clean up drugs and chemicals that collect in waterways. 
  
  Conventional sewage treatment works are designed to deal with organic waste but are less effective with chemicals, hence plants across Switzerland are getting an upgrade.
  
  A 20-minute bus ride from the lake is the Villette wastewater treatment plant, Geneva’s first to treat micropollutants.
  
  The facility filters through 250 liters of water every second. First, it filters out rubbish, food, money – anything people might flush down their toilets (a study found $1.8m (£1.4m) worth of gold flows through Swiss sewers every year). Then fat and sand are removed before the water is treated in huge basins of bacteria that remove organic matter.
  
  Then the water is passed through activated charcoal, which acts like a sponge, absorbing the microchemicals.
  
  Each year, the Swiss are adding micropollutant treatment facilities to seven sewage plants. By 2040, there will be about 140, according to unpublished data from the Swiss Water Association (VSA). 
  
  Switzerland has committed to remove micropollutants from wastewater by 2040. A government program aims to equip 100 wastewater plants with anti-micropollutant technologies that can filter out 80% of all micropollutants. But the project comes at a high cost: around CHF1 billion. 
  
  Now Switzerland has some of the cleanest rivers in Europe and is leading the world in purifying its water of micropollutants: a concoction of chemicals often found in bodies of water that look crystal clear. They include antidepressants, antibiotics, diabetes treatments and anti-inflammatories, which have unknown and potentially damaging consequences for human and ecosystem health.
  
  The public  is privileged to be able to swim in city centers. 
  In Switzerland, you can drink high-quality water straight from the tap.
  
  Today, clean streams, rivers and lakes are pretty much the norm in Switzerland, and for many people, the country is considered a model for its water quality. It is hard to believe that in Swiss lakes, where children are currently splashing around in the hot weather, bathing was once banned.