Types of contamination:
(1) infectious (bacterial, protozoal, viral)
(2) chemical
If the disruption is planned or predicted, then:
(1) Disconnect ice machines, water fountains and other potable water sources.
(2) Develop a contingency plan to provide sufficient bottled water to meet needs during the expected period of service disruption.
Steps during advisory:
(1) Do not consume water from any source using municipal tap water (sink, water fountain, ice machine, other).
(2) Water for drinking should be either bottled water or water brought to a rolling boil for >= 1 minute.
Steps after problem with water supply fixed:
(1) Remove contaminated water from the water pipes by one or more of the following:
(1a) Run all faucets and drinking fountains for >= 5 minutes.
(1b) Use high-temperature water flushing if infectious contamination occurred.
(1c) Chlorination of the water lines if infectious contamination occurred.
(1d) Flush and decontaminate ice machines or other equipment.
(1e) Replace in-line filters that may be contaminated.
(2) Monitor potentially exposed persons for evidence of water-borne disease (infection, chemical toxicity).