Editing Plumbing (section)

== Problems ==
Bacteria have been shown to live in "premises plumbing systems". The latter refers to the "pipes and fixtures within a building that transport water to taps after it is delivered by the utility".<ref name=ehp>{{cite journal|author1=Carol Potera|title=Plumbing Pathogens: A Fixture in Hospitals and Homes|journal= Environmental Health Perspectives|date=August 2015|volume=123|issue=8|doi=10.1289/ehp.123-A217|pmc=4528999|pmid=26230512|page=A217}}</ref> Community water systems have been known for centuries to spread [[waterborne diseases]] like typhoid and cholera.  However, "opportunistic premises plumbing pathogens" have been recognized only more recently: [[Legionella pneumophila]], discovered in 1976, [[Mycobacterium avium]], and [[Pseudomonas aeruginosa]] are the most commonly tracked bacteria, which people with depressed immunity can inhale or ingest and may become infected with.<ref name=ehp2>{{cite journal|author1=Joseph O. Falkinham III|author2=Elizabeth D. Hilborn|author3=Matthew J. Arduino|author4=Amy Pruden|author5=Marc A. Edwards|title=Epidemiology and Ecology of Opportunistic Premises Plumbing Pathogens: Legionella pneumophila, Mycobacterium avium, and Pseudomonas aeruginosa|journal= Environmental Health Perspectives|date=August 2015|volume=123|issue=8|pages=749–758|doi=10.1289/ehp.1408692|pmid=25793551|pmc=4529011|bibcode=2015EnvHP.123..749F }}</ref>
Some of the locations where these opportunistic pathogens can grow include faucets, shower heads, water heaters and along pipe walls. Reasons that favor their growth are "high surface-to-volume ratio, intermittent stagnation, low disinfectant residual, and warming cycles". A high surface-to-volume ratio, i.e. a relatively large surface area allows the bacteria to form a [[biofilm]], which protects them from disinfection.<ref name=ehp2 />