Water Supply Commissioning

Don’t Forget Water Supply Precautions When It Comes to Your Business’s Return to the Office Strategy

As well as organizational matters like how and when office workers are going to return to their desks, businesses should be giving serious thought to other practical concerns within the building such as the safety of the various water systems.

It’s prudent for any water system to be checked before occupation after lockdown to ensure that the bacteriological levels of all systems have not increased during the period of closure, particularly as many office buildings have lain dormant since mid-March. There is a responsibility to allay people’s understandable fears over their health and well-being by ensuring it is safe to re-occupy the building without further risk to personnel who work there. It may also be advisable to carry out a risk assessment to identify any other additional problems that may have arisen.

Toilets, coffee/tea areas and kitchens should have a thorough deep clean to remove any residual contaminants and bacteria from all surfaces: door handles, soap dispensers and hand drying machines etc. Fridges and food storage areas should also be considered areas that require additional attention and deep cleaning.

There are several types of water system that need to be dealt with effectively. Chilled water systems are generally closed water systems, which circulate water to cooling equipment. They are generally protected with inhibiting agents and require no special attention as they are protected by dosing equipment. This gives constant doses of treatment and are not generally accessible to the general public. Provided the pumps have remained in operation during lockdown, they will only require the normal maintenance company to do normal water checks for inhibitors and bacteriological treatment agents.

Condenser water is water that takes the heat away from source and can be closed or open circuit. Closed circuit means that the heat rejection is carried out by fans pushing air through a coil and the air cools the water. There are many forms of heat rejection equipment: dry air coolers and hybrid dry air coolers to name a few.

Dry air coolers require that the condenser water is only treated in the same way as chiller water, as previously described. Hybrid coolers can also use water over the coils to enhance the cooling effect and can be used for free cooling and adiabatic cooling. The water in this process needs to be treated to prevent airborne release of bacteriological agents and is normally treated with chlorination and ultraviolet light to prevent Legionella and other harmful bacteria from multiplying in the water. The risks with using this system are not as great as with cooling towers. However, regular checks on water quality need to be carried out and laboratory tests undertaken, the time frame for receipt of laboratory results should be factored into planning.

Open circuit means that at some point the water will come into contact with the atmosphere, as in cooling towers. The importance of the water quality is paramount in not enabling microorganisms to grow in the water and contaminate the atmosphere. For instance, if not checked, Legionella can cause illness and even death.

Therefore, stringent water testing is required whilst these systems are in operation. This is normally a job for the facilities management team to undertake on site, with the back-up of a specialist water treatment company. They will send off periodic samples to a government-approved laboratory to grow any cultures that may exist in the water and write a test report which must be held on site for scrutiny.

Domestic hot and cold water services supply drinking and washing facility to common areas such as kitchens, toilets and service points including tea and coffee making areas. Generally, the water in these areas does not require attention. The water supplied from the service provider has a residual amount of chlorine in it, to prevent any organisms growing in the water, as it is constantly moving through the pipework in general usage.

Chlorination is carried out after any new installation of the pipework by a specialist company. They will test the water before and after the chlorination flushing process.

However, if the water in the building has been static for more than 30 days, it will be necessary to carry out a full chlorination of the domestic water service within the building, as laid out in BS 6700. This will require the services of a specialist company unless the facilities management team has a qualified technician to carry out the work.

All in all, much to consider behind the scenes, often requiring the expertise of specialists in the field to give occupiers peace of mind when they return to work.

Joe Pitt Photo
Commissioning Director