There's something about moving water that soothes the spirit. The constantly changing pattern and soft murmur of water is calming and mesmerizing. It's even therapeutic. Decades of scientific research show that the sound and visual images that falling water create actually increase creative productivity, lessen stress, purify air, increase employee satisfaction in the workplace, and speed healing.

Serene and beautiful as they are, though, water features are somewhat controversial—particularly in healthcare settings—because bacteria and molds can grow unseen beneath the relaxing façade. Hospital infection control managers, in fact, often reject water features outright to prevent patients from acquiring other infections while in the hospital. They worry that unless the features can be kept virtually sterile, the mist that falling water naturally generates could spread waterborne pathogens into the air, where inhalation can cause illnesses. Particular concern is for patients with weak immune systems—commonplace in hospitals—who are especially susceptible.

It's generally difficult to keep functional water features sanitary enough to meet strict healthcare requirements. Water flows at room temperature and is continually reused, leading to potentially ideal breeding conditions for molds and pathogens. In fact, bacterial contamination in an uncontrolled water feature can quickly soar to as much as 90,000 colony-forming units per milliliter (CFU/ml), according to Dr. Joe Boatman, owner of Quality Environmental Services, an independent testing firm in Boulder, Colorado.

Even frequent cleaning can't wholly eliminate contamination because germs multiply so rapidly. Nor can treating the water with active biocides, such as copper-silver ionization or chlorine, because these agents are only mildly effective against some particularly dangerous pathogens like the bacterium that causes Legionnaire's Disease.

One company, though, has created functional water features that overcome the contamination problem. Denver-area-based Accents In Water's high-performance water systems attract and kill airborne pathogens, filter and trap dust and dirt from the air, and prevent mold and bacteria growth, says Joe Kloppenberg, the company's owner and president. In a healthcare setting, the result actually is cleaner, healthier air, he added.

A division of Kloppenberg, a leading manufacturer of laboratory and medical specialties, Accents In Water achieved hygienic water features by covering interior surfaces with SANIGUARD, an inorganic antimicrobial coating that prevents mold growth. Used in a tank filled with water processed using a reverse osmosis procedure, and an ultraviolet light sterilization system within the water reservoir completes the destruction of bacteria, protozoa, and viruses.

Larger or smaller water features will clean the air either more quickly or less quickly, depending on their size and exact construction. The cleaning ability of a water feature is proportional to the area of its face and the way that water cascades down the face. Features that produce a more turbulent cascade of water are better at cleaning the air.

The cascading water attracts the airborne particles like a magnet. In addition, an ultraviolet light sterilization system placed in the water and the antimicrobial coating applied to the interior surfaces of the feature keep the water reservoir at the base of the feature free of mold and bacteria during operation.

In a study conducted by Dr. Boatman, a water feature was run at various times in a 15′ ×—18′ ×—10′ (2,700 cubic feet) conference room with 400 cubic feet/minute of air entering the room from the HVAC system. The water feature was tested at various times over a 30-day period. Results showed that the water feature cleaned the air about as well as a 425-cubic-feet-per-minute HEPA-style air cleaner.

The concentration of biologically active particles decreased at a rate of greater than 15 percent per hour, which was faster than the removal rate for all dust particles. The faster percentage reduction is because of the small number of biologically active particles compared to the total number of dust particles.

Dr. Boatman then conducted a study of the quality of water to determine whether the water reservoir at the base of Accents In Water's features remains free of mold and bacteria during operation. He found that an ultraviolet light sterilization system is a safe and effective way to control bacterial contamination in the water features when combined with the antimicrobial coating on the interior surfaces of the water feature, which prevents the formation of yeast and mold on those surfaces.

The research methodology was applied to three water features, all containing SANIGUARD antimicrobial coatings on the interior surfaces. The features were different in that:

  • The first water feature did not contain an ultraviolet light sterilization system.

  • The second water feature contained a 20-watt ultraviolet light sterilization system with a pump capacity of 1,800 gallons per hour.

  • The third water feature contained a 40-watt ultraviolet light sterilization system with a pump capacity of 3,000 gallons per hour.

Air quality tests conducted by Quality Environmental Services showed that “when the UV light sterilization system was continuously active for several days, the bacteria concentration was completely controlled.” Molds stayed beneath the detection limit of 18 CFU/ml throughout the testing.

Quality Environmental Services concluded that whenever bacterial contamination is a concern, such as in hospitals and other healthcare facilities, the UV light sterilization and anti-microbial coating “should become a standard part of the water feature system.” To view the research reports, visit

Results like these have convinced Sitrin Healthcare Center of New Hartford, New York, to install an Accents In Water functional water feature in a facility for Alzheimer's and dementia patients as part of The Center for Health Design's Pebble Project. Sitrin hopes that the proven health benefits of water flowing in a sanitary water feature will decrease patient aggression, boost appetite, improve air quality, positively influence behavior, lower pulse rates and blood pressure, and decrease stress for both patients and staff.

As Sitrin is showing, water features are increasingly being studied as part of the evidence-based design movement to advance traditional medicine so it considers the health of the whole person. Practitioners strive to base design decisions squarely on research evidence that particular design elements actually benefit patients.

To make sure that their units are safe, Accents In Water is doing further research with the University Of Colorado, Boulder Campus, under the direction of Dr. Mark Hernandez to continue product improvement and proper use of water features in healthcare environments.HD

Kathy Mason is President of Mason Works, based in Boulder, Colorado.