Usually wastewater is taken through the sewers to a wastewater treatment plant. The plant serves as a very good barrier, removing 90 to 99 per cent of the bacterial content, including multiresistant bacteria.
But heavy precipitation overloads the sewer system. Part of the wastewater – including antibiotic-resistant germs – thus gets into natural bodies of water unpurified. Particular care has to be taken when it comes to hospital effluent, which is much more heavily tainted with resistant bacteria than municipal wastewater.
Retaining hospital wastewater
Hospitals are currently looking into various options to prevent heavily polluted effluent from flowing into bodies of water unpurified. One is retaining hospital wastewater in the event of rain and only releasing it to the treatment plant once the weather is dry again. This measure is being discussed at a number of hospitals, and in the future is to be looked into whenever existing facilities are converted or new buildings are built. By optimising the interplay of the sewer system and treatment plants it will be possible to better exploit the purification effect of plants.