The bacteria that cause Legionnaire's disease grow well in warm tap water installations with ample dissolved organic matter —conditions that support the growth of biofilms, according to an article on the Infection Control Today website.
According to a study published in Applied and Environmental Microbiology, a journal of the American Society for Microbiology, the investigators developed a model system that enabled measurement of biofilm formation and growth of legionella.
They compared a water supply system with a very low concentration of dissolved organic matter with one with a high concentration.
Drinking water from sources with higher concentrations of organic matter induced higher biofilm concentrations that supported legionella growth, according to the study.
Redefining What Mental Health Facilities Look Like
Managing High-Volume Laundry Operations 
University of Pittsburgh Medical Center Falls Victim to Vendor Data Breach
Optimizing the Engineering Design of Ambulatory Care Facilities
Construction Completed on Washington Health Urgent Care Facility in California