The risk management plan (RMP) is required to be reviewed and updated annually, or whenever there are major changes to the operations. It should also be reviewed whenever the risks have changed.
The RMP may need modifying because of:
- changes to the cooling tower system or its use
- changes to the use of the building in which the cooling tower system is installed
- the availability of new information or technology about risks or control measures
- the results of checks indicating that measures to control the system are no longer effective
- a case of Legionnaires’ disease that is possibly associated with the system
- unusual factors such as demolition or construction of buildings on or near the site, or road works or other construction activities that generate dust (9)
- special events that will bring large numbers of people onto or near the site (10)
- a change in the number, or level of vulnerability, of people who may be exposed to aerosols from the cooling tower system – for example, construction of an apartment building near an existing cooling tower would introduce significant numbers of new residents into a risk assessment.
If Legionella is isolated in a cooling tower system, the water treatment program, tower operation and maintenance program of the system must be reviewed within 24 hours of receiving notification of the result (11). Good record keeping – as required by Victorian law – will assist such a review by allowing trends to be monitored. If a site or organisation has multiple cooling tower systems and Legionella has been detected in one system, strong consideration should be given to reviewing the maintenance program and risks associated with all of the systems. This may identify any common problems. In higher-risk or more complex sites, or where large workforces are involved, the department recommends that an independent consultant is engaged to review the maintenance program.
A single person with sufficient authority to initiate action and commit funds must have responsibility and accountability for the operation of the cooling tower system. The overall management of the cooling tower system will benefit if that person has been trained in the management of risks associated with cooling tower systems.
Regular reporting to senior management is an important aspect of risk management, particularly in larger organisations. It is important that those with the power and authority to allocate funding for capital or ongoing improvements have access to sufficient information on which to base their decision making.
9. In such circumstances, options for addressing the increased risk of contamination of the water are to increase the cleaning frequency, increase the rate at which biocide is added, install a side-stream filter, or a combination of these.
10. Special events may warrant increased maintenance to address the increased risk associated with large numbers of people coming to or near a site.
11. Public Health and Wellbeing Regulations 2009