Accepted as our most reliable weapon in the battle to reduce health care-associated infections, hospital tap water has also been recognized as "the most overlooked, important, and controllable source of HAI." Peer-reviewed literature has demonstrated that hospital tap water contains microbial pathogens and that biofilms in water systems resist disinfection and deliver pathogenic organisms to the health care environment. At-risk patients are susceptible to infection through direct contact, ingestion, and inhalation of waterborne pathogens. Systemic water treatment technologies reduce levels of recognized waterborne pathogens; however, they vary in initial and long-term maintenance costs, efficacy against specific organisms, and compatibility with facility plumbing system materials, and they cannot eradicate biofilms within health care facility plumbing. Existing point-of-use filtration technologies have been reported to interrupt clinical outbreaks of infection due to recognized waterborne pathogens in the health care environment and may offer a cost-effective complementary infection control strategy, particularly when targeted for patients at high risk.