Legionnaire's disease is a water borne bacteria that can grow to dangerous levels and is found to be in ornamental (or decorative) water fountains and waterfalls. The disease is associated with waterfalls and fountains in community settings such as restaurants, hotels, offices, shopping malls, and conference centers. Outbreaks of this disease are most commonly found in indoor water features.

Those most susceptible are the elderly, transplant patients, and those with immune compromising illnesses such as AIDS, cancer, diabetes, and chronic lung disease. The CDC Guidelines for Environmental Infection Control in Health Care Facilities advises healthcare facilities to avoid decorative fountains in patient care areas. This requires disinfection and fountain maintenance, which includes daily treatment, weekly cleaning, quarterly inspection, and other additional actions to reduce the growth of legionella.

There are many factors that contribute to the growth rate of legionella. Temperatures between 68-122 degrees Fahrenheit is when legionella grows. 85-110 degrees Fahrenheit is when significant amounts rapidly increase. Indoor water features tend to be at lower temperatures but equipment such as UV units, pumps, and lights can elevate water temperature levels higher than 68 degree Fahrenheit.

Transmission of the disease comes from legionella being aerosolized into small droplets approximately 1 to 5 microns in diameter and breathed into the lungs. Droplets larger than 5 microns usually enters the stomach where legionella is ineffective. There are five main types of water features that have different amounts of aerosol. This includes the following from the least to most aerosol production:

  • Sea Bubbler- enclosed water feature where little, if any, aerosol is produced
  • Cascade- pumps water to the top and cascades down a smooth surface with a very peaceful flow, producing in very little aerosol amounts
  • Water Wall- functions like a Cascade fountain but has fine sheeting of water over a large surface area where there is greater possibility of creating small amounts of aerosol
  • Spray- pumps water through a nozzle forcing water to spray into the air and fall back into the sump. This releases a significantly larger amount of aerosol than the other two above
  • Mist- This operates like a table top humidifier. Humidifiers have a fan to circulate the mist, causing it to quickly evaporate. In contrast, the mister stays around in the air for effect. By design, these create the highest amount of aerosol.

Again, regular maintenance and treatments greatly reduce the risk of legionella growth in most water features. However,  LLWD has addressed this issue, investing time and expertise into developing an affordable, easy, and economical solution. "LL Waterless Liquid", is a synthetic fluid that replaces the traditional use of water and is an excellent alternative for both indoor and outdoor water features. Studies have shown that this ideal fluid is 100% resistant to fungus, bacteria, viruses, and algae. To say that this liquid is virtually "maintenance free" sounds too good to be true.... but LLWD seeks to continually innovate and set new standards in the waterfall industry for both economical and environmental benefits.