Cooling Tower Testing

Overview

Current scientific thinking is that the legionella bacteria that cause Legionnaires’ disease is spread to people via heating, ventilation and air conditioning systems. The area highlighted as the potential start of the problem is the cooling tower. Great care must be taken to ensure that heating, ventilation and air conditioning systems are regularly cleaned and checked for legionella bacteria.

Regulations

Since 1980 legionella has been included as a notifiable infectious disease in section A of the Notifiable Disease Schedule of the Health Act 1956. Guidelines for the control of legionella, published by the Public Health Commission (PHC) in 1995, detail the control measures that should be in place to prevent growth and dissemination of legionella via cooling towers, evaporative coolers and plumbing systems.

The Building Act 1991 states the mandatory requirements to ensure adequate chemical control in cooling towers. Bacteriological tests shall be performed each month for legionella. A total bacteria count by pour plate shall be monthly and total bacteria count by dipslide must be weekly. For safe operation the total bacteria count should not exceed 10^5 cfu/ml.

Airlab Solution

Our professional, independent sampling and analysis service will give you full weekly reporting of results. Our experts can offer advise on all aspects of legionella bacteria and how to prevent it.

For more information on Legionnaire’s disease see our article in About Air.