Cooling Tower Safety: Be Bacteria Aware!
Many people may be unaware of the health hazards associated with cooling towers. However, these systems can pose a significant threat to health, both for employees and the general public, particularly from Legionella bacteria. Wherever they are installed, employers have a duty to ensure a risk management plan is in place at all times that the system is in operation. It is mandatory that maintenance is carried out properly and regularly, including being audited annually by a certified and approved agent. Any changes, including relocation, additions or removal, must be notified to the authorities as soon as possible.
What Are The Risks From Cooling Towers?
Cooling towers can harbour harmful bacteria, such as Legionella, and, when not maintained properly, the chance of inhalation and development of disease increases. Persons responsible for premises where cooling towers are in operation are legally obliged to register the systems and conform to government legislation. Failure to do so is likely to lead to prosecution.
Legionnaire’s disease is a serious illness that can arise from exposure to the airborne Legionella bacteria. Although it is possible for anybody to be affected, those considered to be at higher risk may be:-
· over fifty years old
· a smoker
· a heavy user of alcohol
· a sufferer of existing chronic medical conditions
· be immunocompromised
Symptoms of this serious condition are usually similar to influenza and include fever, headache, shortness of breath, muscle pain and maybe a dry cough. There is usually a two to ten day incubation period from the time of infection to the appearance of symptoms. Any person who is suffering from the symptoms described above and who may have been exposed to Legionella should seek medical advice.
Who Is Responsible? What Needs To Be Done?
People who are responsible for cooling towers should keep up to date with government guidelines related to cooling tower systems and related risk assessment. Helpful advice on Legionella Risk Management can also be found on www.health.vic.gov.au/legionella.
It is essential that attention is given to the effective maintenance of cooling towers in a number of different areas, as laid down in the audit documentation. These are:-
a) Stagnant water
b) Nutrient growth
c) Poor water quality
d) deficiencies in cooling tower system
e) Location and access
f) Any matters identified
Each of these specified areas will be thoroughly checked as part of the authorised audit to ensure that risks to health are minimised.
Maintenance of Cooling Towers
Source: Allied Heat Transfer
It is a legal requirement that the owner of land on which there is a cooling tower system should ensure that registration is made and a risk management plan is put in place, which is reviewed, and updated if necessary, at least once a year.
Cooling Tower Water Quality and Treatment
Water of cooling towers must be continuously treated with one or more biocides know to be effective in controlling growth of micro-organisms, including Legionella. Chemicals or agents which minimise scale formation, corrosion and fouling must be used as well as a bio-dispersant.
Disinfection, Cleaning and Re-Disinfection of Cooling Tower Water
The responsible person must ensure that chlorine-compatible bio-dispersant is added to the recirculating water of the cooling tower system and that the system is then disinfected, cleaned and re-disinfected immediately prior to initial start-up following commissioning or after any shutdown exceeding one month and at intervals not exceeding six months.
Routine Service and Testing Of Cooling Towers
The responsible person must ensure that the cooling tower system is serviced at least once a month to check for defects, that a sample of recirculating water is taken and sent to a laboratory for testing and reporting for heterotrophic colony count.
At least once every three months a sample of recirculating water is taken and sent to a laboratory for testing and reporting for Legionella.
The responsible person must keep records for each cooling tower system owned, managed or controlled by them detailing all maintenance and corrective activities undertaken and all microbiological test results of samples taken for the preceding year.
Further Points for Consideration
Outbreaks of Legionnaire’s disease can be very serious, resulting in much distress, suffering and even fatalities. Many people may be affected. It is a legal requirement that those who are responsible for overseeing the running of cooling towers follow procedures properly to keep risks to their employees and the general public to a minimum. Failure to do so is very likely to lead to prosecution.
Author Bio: Allied Heat Transfer is a specialist company which designs and manufacturers oil and air cooler systems. Allied Heat Transfer custom build systems to your specific requirements which can offer longer service life and easier maintenance. Why not visit the website or contact Neil at Allied Heat Transfer to discuss your requirements further?