The Environmental Protection Agency (EPA), the American Public Health Association (APHA), and the American Water Works Association (AWWA) have set a limit of 500 CFU/mL for aerobic, heterotrophic, mesophilic bacteria in drinking water.1,2 Treated municipal water enters healthcare facilities via the water main and is distributed throughout the buildings by a network of pipes. To minimize potential stagnation, pipe-runs should be as short as practical and they should be insulated.1
In addition to stagnation, the production of aerosols and wet surfaces also facilitate the multiplication and dispersal of waterborne pathogens. Measures to prevent the spread of waterborne pathogens include hand hygiene, glove use, barrier precautions, and eliminating/minimizing contamination at point-of-use fixtures.1,2 Infection prevention strategies related to hand hygiene and the use of personal protective equipment are presented elsewhere.4,5
Universal point-of-use fixtures for water in healthcare facilities include sinks, faucets, toilets, and eye-wash stations.1,2 The potential for these fixtures to serve as a reservoir for pathogenic organisms has long been recognized. Sinks, faucets, and toilets should be cleaned and disinfect on a regular basis using an EPA-registered product (see section on Fomite-related Infection Prevention and Control). Eyewash stations should be flushed weekly with sterile water.
Special point-of-use fixtures include high-speed handpieces, sonic and ultrasonic scalers, and air-water syringes. These devices are connected to a water source by dental unit waterlines (DUWLs), which consist of small-bore plastic tubing. The presence of biofilms of waterborne bacteria (e.g., Legionella spp., Pseudomonas aeruginosa, and NTM) in DUWLs has been confirmed.1,2 Strategies to maintain acceptable water quality in oral healthcare settings are summarized in Table 2.1,2