Legionnaire's disease
The problem
In the wake of the outbreak of legionnaire's disease in Cumbria and subsequent cases both at home and abroad, it is important to remember that air-conditioning plants are not the only possible cause of the infection.
Susceptible guests, customers, contractors and staff can contract the disease by inhaling contaminated water droplets or spray-mists both from air-cooling systems and anything dependent on building water services. This includes bathroom showers and spa baths to ornamental fountains, and even fine spray on refrigerated food displays.
The law
Hospitality and leisure operators must remember that the Health & Safety at Work Act 1974 places an obligation on employers to ensure, as far as reasonably practicable, the health, safety and welfare of their employees, and persons not in employment - such as guests and contractors.
Expert advice
Legionnaire's disease - the name commonly given to the pneumonia caused by the organism Legionella pneumophila - cannot be contracted through drinking contaminated water. The organism naturally occurs in reservoirs and exists in building water services - particularly colonising water systems incorporating cooling towers or evaporative condensers, as well as hot and cold water services. This makes fixtures such as bathroom showers, spa baths and ornamental fountains a big a risk to clients and employees at water-cooled air-conditioning plants.
With current legislation and the recent outbreaks of the disease in mind, it is advisable to take note of the HCIMA's technical briefing document, Precautions Against Legionnaire's Disease.
These range from issues involved with new installations; cold-water tanks and systems; hot-water systems; calorifiers, to cooling towers; swimming pools, spa baths and whirlpool baths. There is also a section dedicated to the necessary safety precautions for maintenance personnel.
Check list
It is not possible to reproduce the HCIMA document in its entirety here. However, the following is a sample check list from the document on the subject of cooling towers.
- Ensure a suitable water treatment programme controlling scale, corrosion and microbial growth is in place and is being suitably monitored and logged.
- Ensure all effluent runs to a foul sewer and that a "Consensus to Discharge" is sought from the local water company.
- Test for Legionella bacteria every six months.
- At least twice a year the tower should undergo a deep-cleaning/strip-down and sterilisation programme to ensure the disinfection process complies with Health & Safety Executive (HSE) requirements.
- Ensure water treatment programme is reinstated immediately after cleaning process.
- All cooling towers should be constructed in such a way as to facilitate cleaning and maintenance, and with materials that do not promote bacterial growth. High efficiency drift eliminators must be fitted.
- If the plant is shut down for any time, it should be drained and left dry.
Contacts
Professor John Forte, TAG chairman, HCIMA
Tel: 020 8772 7400
To purchase the HCIMA brief Precautions Against Legionnaire's Disease (£5), contact the HCIMA on 020 8772 7400, or e-mail: library@hcima.co.uk. HCIMA members can download the briefing document from the HCIMA Web site: www.hcima.org.uk.
To learn more about the disease, go to:www.amm.co.uk/pubs/fa_legionnaires.htm
Further reading
* BS: 6700 (1987): British Standards Specification for Design, Installation, Testing and Maintenance of Services Supply Water for Domestic Use Within Buildings and their Curtilages - BSI Milton Keynes.
* The Control of Legionella in Health Care Premises - A Code of Practice (1988), Department of Health & Social Security. HMSO.
