Our objective is to identify all water systems where legionella bacteria could potentially grow and assess the risk of people being exposed to contaminated aerosols from them. All water systems need to be included in the legionella risk assessment..

We recommend that a full risk assessments should be undertaken bi-annually This may need to be reviewed sooner if there are changes to the building, the water system or its use, signs that the current control measures are no longer adequate, or a case of Legionella/Legionellosis is associated with the system.

During a full risk assessment we undertake to;

  • Check the cold and hot water temperature at outlets- To prevent Legionella growth, cold water should be maintained, where possible, below 20C and hot water stored at 60C and distributed at 50C. 
  • Check hot water storage including cylinder thermostat where present. We also test the flow and return pipe temperatures
  • Check the cold water storage tank,where present for debris in the system, such as rust, sludge or scale (often a problem in old metal cisterns), that could provide food for growing legionella
  • Check areas where stagnant water occurs (deadlegs), e.g. pipes to a washing machine that is no longer in use
  • Check shower heads for lime scale build up.
  • Provide a detailed a fully compliant report complete with recommendation where appropriate. The level of risk is determined by assessing the likelihood of a hazard occurring and the severity of the effects of the hazard.

    The Risk Assessment is produced using a simple 6 level risk system. Each risk factor is assessed individually and then an overall rating is given in the Assessment Summary section.