Drinking Water Tests

see also Bacteriological Analysis of Industrial Systems

Legionella bacteria is only one of the many bacteria we test for. Our laboratories are UKAS accredited for all the normal pathogens found in water, pharmaceuticals and food.

(drinking water tests must be picked up and dispatched to our laboratory the same day)

Total Viable Count (TVC)
A Total Viable Count (TVC) at 22°C and 37°C is the basic test for drinking water quality. The test gives a reading for all bacteria present - but not what type of bacteria. The results should be monitored over a certain period in order to identify significant changes in total viable count.

Total and Faecal Coliforms, including Escherichia coli
Testing for coliforms is an important routine test for drinking water, as it is a very sensitive test for faecal contamination. If colonies grow following the water filtration, then a test is carried out to determine whether the organisms are E. coli or other coliforms.

Faecal Streptococci
Faecal Streptococci are a secondary indicator of faecal pollution and a test for these organisms is usually carried out along with a test for coliforms. If positive result is obtained in this test, then any coliforms present are assumed to be faecal in origin.

Clostridium perfringens
Clostridium perfringens is the last indicator of faecal contamination and is almost always tested for in conjunction with coliforms and faecal streptococci. It is a good test to determine whether remote or intermittent contamination is occurring as the spores can persist in the environment for a considerable time.

Pseudomonas spp. including Pseudomonas aeruginosa
Pseudomonas spp. are common environmental organisms. However, they can easily colonise water systems forming thick biofilms which can affect the taste and colour of the water, and indicate a dirty system that requires cleaning. Pseudomonas aeruginosa is an opportunistic pathogen which can cause illness. This organism should be absent in food and pharmacutical production, healthcare premises, swimming pools, and other places that have regular human contact. In chilled water circuits Pseudomonas can cause loss of heat exchange and under deposit corrosion.

Staphylococcus aureus
Staphylococcus aureus is a human pathogen which can particularly affect the old, young and hospitalised patients. It is rarely found in water as it cannot survive for long in this environment, however, if present it may cause illness. This test would only need to be carried out if a particular complaint or illness was recorded as a result of contact with the water.

Bacteriological Analysis of Industrial Systems   How to Take TVC Samples