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Water Sampling & Testing

To ensure that conditions within your water systems do not support and encourage the proliferation of legionella and other water-borne bacteria it is advisable, in some situations, to undertake a regime of water quality monitoring. There is no legal requirement for water samples to be regularly collected for analysis however it can help illustrate due diligence.

A water risk assessment will help identify and recommend a water sampling and testing regime appropriate for your property’s water related plant and risk factors.

When is Water Sampling and Testing Recommended?

The ACoP L8 recommends that where there is doubt about the efficacy of the control regime, or it is known that recommended temperatures, disinfectant concentrations or other precautions are not being consistently achieved throughout the system it is “good practice” to collect water samples for microbiological analysis on a 6 monthly basis.

In relation to water temperatures water sampling and testing should be considered when the target control parameters are not met (i.e. where temperatures are below 50 °C for hot water services or exceed 20 °C for cold water systems) as outlined within HSG 274 part 2.

Sampling should also be considered from areas subject to:

  • Low usage or infrequently used (e.g. outlets within vacant areas or low occupancy areas of a building, outlets within remote areas of a building such as roof level or basement taps or in plant rooms)
  • Stagnation
  • Excessive storage capacity
  • Dead legs / blind ends
  • Excessive heat loss / heat gain
  • Cross flow from the water system
  • Or any other anomaly

We can arrange scheduled water sampling for your property, or just a one-off sampling or quality test for piece of mind. Our team are more than happy to advise you regarding your exact sampling requirements. All water samples are collected in accordance with BS7592 Sampling for Legionella organisms in water and related materials and then sent to a UKAS accredited laboratory for analysis.

A typical water sampling regime would include:

  • Mains Cold Water - Total Viable Counts (TVC's) at 22 & 37, Total Coliforms & E-coli
  • Cold Water Services - Legionella, Total Viable Counts (TVC's) at 22 & 37, Total Coliforms & E-coli
  • Hot Water Services – Legionella only

Water Sampling Test Results

Legionella water sample results are issued after 10 days of incubation, with “interim” presence or absence results issued after 7 days of incubation (*NB interim results are not always issued by labs).

If required Metro SRM’s water safety team are able to interpret the results issued by the laboratory and issue recommendations where necessary.

Chlorination and Water Treatment

Where required, we are able to provide chlorination, disinfection and water treatment solutions to help you achieve and maintain good standards of water hygiene, and control levels of waterborne bacteria in your water systems.

Our services are delivered by water hygiene experts who combine specialist equipment and water treatment technologies to help clean and disinfect your water systems, extending asset lifecycles and improving water safety and regulatory compliance. All water hygiene and chlorination work is undertaken to meet British Standard PD855486:2015.

Further Information

Please contact us on 0845 058 9999 for further information.


Get in Touch

Metro Safety
Metro House
79-80 Blackfriars Road
London SE1 8HA
0845 058 9999

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