Environmental Water Solutions
Bacteriological Control
Legionella is not the only bacteria that can live in water systems and cause harm to humans.
Psudomonas aeruginosa is one of the harmful species of the usually harmless Pseudomonas bacteria. As with Legionella, it mostly affects people that are immune-suppressed and causes respiratory infections as well as wound and ear infections.
Unlike Legionella, Pseudomonas can be transferred from person to person as well as from surfaces and the environment, so good hygiene in conjunction with the correct water treatment program is the most effective way of controlling it.
Legionella and Pseudomonas thrive in similar conditions, so the control regimes for both are very similar. A Legionella risk assessment will outline ways in which the threat of Pseudomonas can be reduced but continual monitoring and sampling will ensure that any risk that arises is dealt with appropriately.
Total viable count (TVC) tests are carried out to identify the number of different kinds of bacteria, such as coliforms and E.coli per millilitre of water.
The table below briefly outlines each test.
|
TEST |
DETAILS |
ACCEPTABLE LEVELS |
|
22°C |
This is a general temperature and covers mostly harmless bacteria that would normally live in the environment. |
No standard except for food industry:
However the general trend should be observed and an increase could suggest there is a source of contamination. |
|
37°C |
This temperature is the same as body temperature and therefore tests for bacteria which are more likely to cause harm. |
|
|
E.coli |
The presence of E.coli in itself is not a problem (the species that causes infection in humans does not live in water), it does not survive for long in water but it indicates recent contamination and therefore the presence of other potentially harmful bacteria. |
Not detected in 100ml. |
|
Coliforms |
Environmental bacteria found in animal intestines. As with E.Coli (a type of Coliform) they are used to indicate the presence of other, harmful bacteria. |
Not detected in 100ml.
In our experience, when Coliforms are detected in a sample, it is simply the case that the tap needs cleaning! |
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