Overview - Bacteriology
Swimming lakes in Schleswig-Holstein must comply with the requirements of the “Regional decree for the quality of bathing waters.” Monitoring of bathing areas takes place in the swimming season which runs from June to the middle of September. To do this, a water test is made every 14 days and at the same time a sensor test of the water is carried out. Then the water is tested for bacteriological parameters in a laboratory. The parameters include total coliform bacteria and faecal coliform bacteria.
What are total coliform and faecal coliform bacteria?
Total coliform bacteria include both germs which are faecal in origin and environmental. These do not cause infections but indicate that the bathing water has been polluted by sewage. Faecal coliform bacteria usually occur in great numbers in the large intestine in humans and mammals. They do not trigger illness themselves but they are a sign that bathing waters have a possible faecal cause of pollution.
What are the limit values?
The Bathing Waters Decree defines standard values and limit values. Excellent water quality is specified as that which falls below the standard value. Even if the standard value is exceeded there is no risk to health.
The limit value however is a maximum value which if exceeded does not exclude a risk to health. This usually results in the authorities responsible in closing the bathing area.
|
Standard value
CFU*/100 ml |
Limit value
CFU*/100 ml |
Total coliform bacteria |
500 |
10,000 |
Faecal coliform bacteria |
100 |
2,000 |
* CFU – colony-forming unit
