Topicality and need

Clean drinking water: a scarce commodity

Global water consumption is growing continuously; available resources are becoming more and more precious, yet at the same time, the contamination of drinking water with germs, for example, or chemical residues, is increasing. The risks of this type of contamination are incalculable. This not only applies in threshold countries, but also in highly developed industrialised areas such as Germany, Europe and the USA.
Each year, around 2.2 million people die from diseases communicated through drinking or process water, and more than 1,000 of these people live in Germany.

Drug residues, fertilisers and other toxic substances in the water in particular represent a problem that needs to be taken seriously. Bacterial contamination of the groundwater with Legionella, Cryptosporidia and EHEC bacteria also represent a serious danger. The cause of this is often a result of geology, since the natural filtering effect of the groundwater layers is becoming less and less adequate for the complete removal of bacteria.

New technologies are therefore required in order to obtain safe drinking water from previously unusable water sources. The German government has recognised this, and on 1st January 2003 passed the Drinking Water Directive (Trinkwasserverordnung, TWO).
This directive adopted the strictest EU threshold values for potential pathogens in drinking water. The threshold values for bacterial counts stand at 100 CFU (colony-forming units) per millilitre for the total bacterial count for E. coli; Enterococci and Coliform bacteria must not be demonstrable in a 100-ml water sample after an enrichment process.
However, a large proportion of public drinking water supply companies provide contaminated water to their consumers.

Drinking water purification using ultrafiltration can provide a remedy: filtering with this method removes more than 99.99 per cent of all germs. This means drinking water that is free from harmful microbacteria.