What Water Systems in Workplaces are Potential Sources of Legionnaires' Disease Bacteria (LDB)? The primary sources of exposure to contaminated water in commercial and industrial facilities are water-cooled, heat transfer systems such as cooling towers or fluid coolers, and warm water sources such as domestic hot-water systems. In studies conducted by Hodgson and Casey in 1998, several thousand samples collected from a variety of sources showed: Cooling Towers: 6.3%, Potable Water Distribution Systems: 7.0%, Hot Water Heaters: 12.0%. Operating Systems: Use the following modules to review maintenance, sampling protocol, treatment, and design considerations of each operating system. Health Care Facilities and LDB: (1) The Joint Commission for the Accreditation of Healthcare Organizations (JCAHO) issued a new standard that became effective January 1, 2001. This standard, numbered EC 1.7, requires all JCAHO accredited facilities to have a management program to "reduce the potential for organizational-acquired illness." It holds the health care facility responsible for "managing pathogenic biological agents in cooling towers, domestic hot water, and other aerosolizing water systems." (2) The American Society for Healthcare Engineering (ASHE) recommends that health care facilities conduct a risk assessment of potential sources of LDB and develop a management plan for maintenance and operation of water systems. See more from topic source: https://www.osha.gov/html/a-z-index.html