Hot and Cold Water Clean and Disinfections

Bacterial sampling and high bacteria counts

During a building’s operational life, its water systems are highly likely to require cleaning and disinfection of the cold-water storage tanks, calorifiers and system pipework. Where this work is identified as being required, either due to visual inspection of cold water tanks or from positive bacterial samples, disinfections should be carried out in accordance with ACoP L8 and PD855468:2015.

When doing this, it is essential to seek the assistance of qualified, competent professionals like those supplied by Rock Compliance.

Upon visiting your premises, our engineers will:

  • Provide a written scope of works
  • Advise on which disinfectant product should be utilised for the works
  • Advise on the effect it will have on the water systems and the occupants of the building
  • Obtain discharge licenses from the appropriate water authorities
  • Monitor disinfectant levels, pH and contact times of the disinfectant during works
Water Hygiene Hot and Cold Water Clean and Disinfections
System drain-down

These works will usually include a drain-down of parts of the system. This often comes with confined space access for personnel to enter large storage vessels, which requires the operatives to not only be trained in disinfection procedures but also safe systems of work and emergency response in the event of collapse or incapacitation within confined spaces.

Typically, these works will also involve working at height in order to access parts of the system located in roof voids and work at high level on the top of large cold water storage tanks. Because of this, additional works may be required to provide safe access, such as boarding-out loft spaces and providing adequate lighting.

Validation sampling

Following disinfection works, validation sampling will be required when works are conducted in response to previous high bacterial counts. These samples should be taken no sooner than 48 hours after the disinfection works to ensure that any residual disinfectant in the system does not provide a false representation of the effectiveness of the disinfection.

In systems where high levels of bacterial infection are present, repeated disinfections may be required in order to successfully remove any biofilms that could be harbouring bacteria. Installation of secondary disinfection technologies may be required to provide ongoing system control for the growth of Legionella.

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Whether it is an issue of compliance, an investment decision, or you are just not quite sure whether your existing provider is giving you what you want, please contact us.  We will be happy to give you advice on how to create low risk, compliant water systems, ensuring spend is minimised and predictable.

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