Hot and Cold water monitoring & inspection (HSG 274 Part 2)

The Health & Safety Executive Aproved Code of Practice (ACoP) L8 “Control of Legionella Bacteria in Water Systems” and supplementry guidance HSG 274 Part 2 The control of legionella bacteria in hot and cold water systems states: –

Paragraph 2, Any water system that has the right environmental conditions could potentially
be a source for Legionella bacteria growth. There is a reasonably foreseeable
legionella risk in your water system if:

  • water is stored or re-circulated as part of your system;
  • the water temperature in all or some part of the system may be between
    20–45 °C;
  • there are deposits that can support bacterial growth, such as rust, sludge,
    scale and organic matter;
  • it is possible for water droplets to be produced and, if so, if they can be
  • it is likely that any of your employees, contractors, visitors etc could be exposed
    to any contaminated water droplets.

Clearly hot and cold water systems fall within this description and therefore are likely to require implimentation of a written scheme of control, including monitroing, inspection and record keeping.

Domestic Operator Training

HSG274 Part 2 hyperlink

The frequency of inspecting and monitoring the hot and cold water systems will depend on their complexity and the susceptibility of those likely to use the water. The risk assessment should define the frequency of inspection and monitoring, HSG274 Part 2 Table 2.1 provides a checklist for hot and cold water systems with an indication of the frequency of inspection and monitoring.

Hot & Cold water monitoring

Monitoring of HWS return systems

Hot water system return pipes – stagnation often occurs, particularly at points furthest away from the water heater, where circulation has failed and the hot water has cooled.

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