cooling towers

Cooling Towers

Cooling towers have the ability to spread Legionella over a wide area and consequently can be regarded as one of the most dangerous and regulated of sectors in water treatment and Legionella control. However, if cooling towers are well maintained and all the suitable control measures are being implemented and monitored then they can actually present a lower risk than a shower at home.

The role of the Hydrosense test is in supporting the practical implementation of control and monitoring measures to assist clients in meeting their Legionella control responsibilities. Testing of the cooling towers has to be performed on a regular basis. More frequent sampling is recommended in cases such as:

  • Outbreaks
  • Establishing a new or modified treatment programme
  • If a legionella-positive sample is found as part of the review of the system risk assessment, to help identify the source of the contamination and check when the system is back under control
  • The risk assessment indicates more frequent monitoring is required

Owners are ultimately legally responsible and must take an active role in managing the control of Legionella within their system.

From a legal, and regulatory position, it is not sufficient to hire a water management company and then rely on their best efforts. The facility owner has to be sure that all reasonable practical control measures are being taken, not just that the minimum requirements are being fulfilled.

In practice even the best managed water systems are subject to failures and cannot always meet the required control criteria. Water temperatures vary within a system and can go out of control ranges, dead legs are not properly controlled and even within standard maintenance cycles there will be a build-up in bio-films (slime) which are breeding grounds for Legionella. Controlling Legionella is the most important objective, but be very wary of the advice that your system is always controlled.

Monitoring is essential to demonstrate how well your control is performing and as such is an important part of the overall control system.

The Hydrosense test provides an excellent way to monitor the effectiveness of a control system. Hydrosense provides fast results on site, without expert assistance, so it is simple to monitor between regulatory quarterly checks. If there is a problem, it is immediately identified and prompt remedial action can be taken – protecting clients, staff and the public. This also protects your business from public liability claims and your reputation.

Cooling towers have a specific problem with the cooling tower packs. Bio-film builds up on the cooling surfaces. These are great places for Legionella to grow. Under normal working procedures these packs have to be dismantled and disinfected regularly. The Hydrosense bio-film kit provides all of the tools required to monitor the state of the cooling tower packs in situ, both before and after treatment, thus saving considerable amounts of money in unnecessary down time.

Further once a problem has been identified and dealt with, it is possible to check the efficacy of the remedial action quickly. This provides the confidence and the data on which to restart operations. Why wait 10-14 days for lab results?