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Microbiological & Legionella Testing

Do I need Microbiological Sampling?

  • Domestic water systems are supplied with water fit to drink, so ACoP L8 advices that regular microbiological sampling is not required.
  • Where potable (drinking water) water is stored, BS6700 sets out a regime where 6 monthly microbiological activity is measured.
  • ACoP L8 recommends that sampling for Legionella should be carried out when:

    1. Systems treated with biocide where storage and distribution temperatures are outside acceptable parameters
    2. In systems where the control measures are not consistently achieved
    3. Where a Legionella outbreak is suspected (download action levels from ACoP L8)
    4. High risk areas where the users of water systems are in a highly susceptible category e.g. hospital wards with immunologically compromised patients

What is involved during Microbiological sampling?

W.E.T can test for over 50 different types of microbiological activity and water chemistry analysis.

An engineer will visit your site, undertaking an audit of the water system to determine the appropriate number of samples to take and their locations.

On some occasions samples can be tested on site, but microbiological samples need to be incubated, so they are taken to our UKAS accredited laboratory for analysis.

The most common microbiological samples are:

Test Incubation Period Purpose
Dip slides On site/ Instant Semi-quantitative measurement for the general presence of bacteria in water
TVC - Total Viable Counts 2-5 Days Basic test of water quality
Determines overall levels of contamination
Essential that TVC falls within recommended guidelines for the control of Legionella
Coliforms 24-72 Hours Indicates potential contamination of water source
Evaluates general quality of the water
Two Types: Coliform and Faecal Coliform
Coliform – indicates water pollution
Faecal Coliform – indicator of water contamination from human and other warm blooded animals' waste products
E-Coli 24-72 Hours Coliform bacteria are used to indicate the presence of other bacteria
E-Coli does not live very long in water so is an indication of recent contamination
Their presence also indicates the possibility of similar bacteria also being present
Legionella 72-96 Hours Legionella is commonly found naturally water systems; an increase to harmful levels can cause Legionnaires’ disease
Legionella sampling is required under ACoP L8 guidelines to identify systems which may pose a risk
Pseudomonas Up to 7 Days Appropriate to test for in certain water systems
It is a common environmental organism which easily colonises water systems and can produce a biofilm which affect taste and colour of water. Harmful levels can cause severe infection; particularly in immunocompromised people

Why choose W.E.T for your Microbiological sampling?

  • Strictly compliant:
    All microbiological samples are taken, transported and analysed under UKAS accredited conditions as stipulated by ACoP L8 to keep you compliant.
  • Experience:
    Over 500 samples are taken and tested each year by our engineers, overseen by an operational management team qualified in Microbiology so you can be reassured of our experience and qualification.
  • Record keeping:
    Each sample is issued a unique reference and is logged on an online portal so we can trace their status. Full reports are then interpreted and issued by our dedicated account management team to ensure your records are compliant.
  • Responsive and reassuring:
    In the event of any out of range results, we have strict procedures in place to remedy the situation, fast tracking action where possible and responding to site usually within 24 hours to minimise any required system shut down.
  • Quality standard:
    All testing is undertaken using equipment, which has been pre-calibrated in accordance with UKAS accredited test methods and managed under our quality standard ISO 9001:2008 to ensure your results are recorded accurately, every time.
  • Accredited by the Legionella Control Association:
    Services are carried out under internal procedures which have been accredited by the Legionella Control Association to ensure year round compliance and quality of service to our clients.
  • National Water Hygiene Card Holder:
    All W.E.T engineers are National Water Hygiene Card holders, which is recognised by all UK water companies and is a pre-requisite for any work on the water distribution network.

© Water Environmental Treatment Ltd.
Claymore, Tame Valley Industrial Estate,
Tamworth, Staffordshire. B77 5DQ

Registered in England No. 2685141 | Tel: 01827 288810 | Fax: 01827 261390