Preventing Legionnaires' disease

This information is provided by

Netherlands Enterprise Agency, RVO

Do you own a business or building where there is a risk of people catching Legionnaires’ disease? You must be aware of the dangers of Legionella and prevent its growth to dangerous levels.

Legionella is a bacteria that can cause an infection of the airways called legionellosis, or Legionnaires’ disease. Legionella bacteria may grow in water with a temperature between 20 and 50 degrees Celsius, and in stagnant water. Legionella can for instance grow in tap water, swimming pools, hot tub and bath water, fountains and sprinkler water at garden centres and (car) washing machines, wastewater plants, or cooling water in wet cooling towers.

Building owners are responsible for the quality of tap water. They must ensure that the health of people in contact with this water is not at risk. There are practical measures for complying with this duty of care (in Dutch). The measures include letting all taps and showers run at least once a week.

High-risk institutions

Some businesses and institutions (in Dutch) are subject to stricter regulations on primary legionellosis prevention (in Dutch). These include:

  • hospitals
  • healthcare institutions (care homes, mental health centres, specialised care)
  • saunas
  • swimming pools and establishments with pools and showers on their premises, such as wellness centres and sex clubs
  • hotels
  • holiday parks
  • campsites
  • bed and breakfasts with more than 5 beds
  • marinas
  • petrol and service stations with shower facilities
  • prisons and cells in police stations
  • refugee centres

Risk analysis and management

Do you own a business mentioned above, or does your building house a business mentioned above? You must ask a certified company to conduct a risk analysis and draw up a Legionella management plan of your water supply system.

A Legionella management plan describes the periodical preventive checks and the maintenance of your water supply system. This can only be done by a company with the right certification (in Dutch). Companies should comply with the latest Legionella risk and management plans (BRL 6010, in Dutch).

Water checks

You must have your water checked at least twice a year by a certified company. If there are more than 100 colony-forming units of the bacteria per litre, you have to take action. This can include disinfection, installing filters, or closing the infected water point off.

If the standard of 1,000 colony-forming units per litre is exceeded, you must report this within 48 hours to the Human Environment and Transport Inspectorate (Inspectie Leefomgeving en Transport, ILT, in Dutch). You have to keep records of any measures you have taken and when these were taken.

The rules for bathing water are different. Does the bathing water contain 100 colony-forming units of Legionella per litre or more? Then you have to report this to your provincial authority (in Dutch) as soon as possible.

Wet cooling towers

Wet cooling towers pose an extra risk to spread the Legionellabacteria, as they release droplets of water into the air. If you use a wet cooling tower for your building or work, you need to notify the Environmental Agency (Omgevingsdienst, in Dutch).

Protection of staff, guests and environment

You must indicate how you protect your staff and guests from exposure to the Legionella bacteria. You do so in your risk inventory and evaluation (RI&E). For wet cooling towers, the protection of the environment and living organisms should be included in the RI&E as well.

This information is provided by

Netherlands Enterprise Agency, RVO