EHEC bacteria of this strain occur extremely rarely in waste water and other bodies of water. As the proportion of the population infected with EHEC is very low, the intestinal bacteria which may be present in waste water only rarely proves to be EHEC. The latest data prove the following: the infectious strain has only been detected one single time in the many water samples that have been taken in the meantime, and it was no longer present in follow-up tests. There has been no indication whatsoever to date that the EHEC strain which has triggered the current wave of infections can reproduce in bodies of water.

The current infectious strain of EHEC is an E. Coli bacterium. Drinking water is checked daily for presence of these bacteria. All waterworks with more than 5,000 connected customers must submit E. Coli reports to the Federal Environment Agency, and they show that E. Coli is virtually non-existent.

In the past, there have been occasional incidences of E. Coli detected in very small public waterworks and in certain regions that have house wells. E. coli quite often are harmless inhabitants of the intestine, and in drinking water they are indicators of the possible presence of other pathogens. This requires an improvement in monitoring in the near future. Yet, in its talks on 22 June 2011, the Drinking Water Commission concluded that any risk posed by the current infectious EHEC strain can be ruled out. It would take a well in an area with many infected patients coming into direct contact with sewage, and that situation is unlikely as the incidence of newly sickened is on the decline.