How to Conduct Water Risk Assessment in a Commercial Building

15th July 2016

Water, provider of life and potential killer if the risks of storing and using it are not properly assessed.

Commercial building owners or operators must have a robust water risk assessment in place to guard against bacterial contamination which can lead to outbreaks of life-threatening diseases, such as legionella. Owners of care homes where residents are vulnerable to infection must take particular care, but the duty to protect the public and building users is a legal obligation to all owners.

Hot and Cold Water Systems

Both hot and cold water systems need to be assessed. In the hot water system, the tank or cylinder should hold the water at a minimum of 60°C and it should move through the system at 50°C. Clearly this poses a risk of scalding, so a mixer tap on sinks and other outlets needs to be fitted. The checks on the hot water tank should take place monthly. At intervals, you should drain the hot water tanks and cylinders, and check to make sure they don’t have any debris in them and are not corroding.

Cold water needs to be cold not tepid – it should be kept and distributed at a temperature of less than 20°C. The cold water storage temperature should be checked at least twice a year, and periodically water tanks need to be drained and cleaned.

Shower heads represent a major risk because stagnant water encourages legionella bacteria to grow. If a shower or tap is not used very often, it should be flushed through every week and a minimum of four times a year shower heads and hoses should be cleaned and de-scaled.

If you are putting in a new facility or renovating a building, you can reduce the risk posed by water by keeping pipework runs as short as possible. A specialist company will be able to advise on suitable materials for new tanks, which will minimise the risk of bacterial growth. Prevent insect and other contaminants by fitting the new tank with a lid and screen.

Competent Risk Assessment

Your risk assessment should both identify the possible hazards in your building and assign a likelihood of the risk occurring. If you have a number of high risk issues, you need to increase the controls you have in place to prevent harm. These should, in any case, include regular testing of water samples to see what the levels of harmful bacteria are.

As part of your risk assessment, you should document what training you have given to maintenance and other staff, and what action you would take if harmful levels of bacteria were discovered.

The Health and Safety Executive (HSE) mandates that the person carrying out the risk assessment and specifying the control measures must be competent to do so. If you don’t have expertise in this area, you would be well advised to seek help from a professional consultancy who can demonstrate that they have the relevant experience and qualifications.