1. Does your decorative features create a spray and/or mist?
To cause disease, Legionella bacteria contained in small water droplets must be inhaled into the lungs.
For this reason, a decorative water feature that creates a spray or mist, even if only on a windy day, carries a
higher risk. A water feature which is fully enclosed in glass or does not create any spray at all poses a much lower
risk of spreading Legionnaires’ disease than a feature that sprays or mists water.
2. Are there submerged lights in your decorative feature?
Submerged lighting is often found in decorative water features to increase aesthetic appeal.
However, equipment such as lights and pumps can elevate the water temperature to above 68°F,
leading to conditions which are conducive to rapid Legionella bacteria multiplication. Certain types
of lights which produce less heat when operated should be used whenever possible.
3. Do you drain, clean, and sanitize the decorative feature at least once a year?
In addition to using disinfection chemicals (such as chlorine, if approved by the manufacturer) on an
ongoing basis, the decorative water feature should be drained and cleaned periodically. It is important
to note that the amount of exposed surface area will impact the potential for biofilm growth. A water
feature with more surface area, such as one with many rocks, has a greater potential for biofilm growth.
Records of this preventative maintenance must be kept available.
4. Does the water used in your decorative feature sit stagnant?
Flowing water tends to minimize biofilm growth, while stagnant water will lead to biofilm conditions.
Legionella bacteria will be more likely to be found in a decorative water feature which is stagnant than
in one that is constantly recirculating. If the water features has a recirculating pump, but it is turned off
for multiple days in a row, consider draining and cleaning the feature.
5. Does the water used in your decorative feature appear cloudy at times?
Cloudy water may be an indication of high concentrations of bacteria, producing ideal conditions for biofilm growth.
Filtration is one way to decrease contaminants which cause cloudy water conditions. Filters must be disinfected or
changed regularly, as per manufacturer’s recommendations.