Water Safety Guidelines

For the most recent Food and Water Safety Guidelines in a PDF file, see the document at the bottom of this page.

Public water quality and treatment varies throughout the United States, so always check with the local health department and water utility regarding the safety of household and community tap water and ice for use by immunosuppressed persons.

Tap Water
Water from your home faucet is considered safe if your water is from a city water supply or a municipal well serving highly populated areas.

Well water
Well water from private or small community wells is not considered safe for consumption by persons considered immunosuppressed and at risk for infection unless it is tested daily and found to be negative for coliforms and Cryptosporidium organisms.

Examples of ways well water could become contaminated:

• construction occurs near the well
• well depth is shallow
• well is located near a dairy or large numbers of livestock
• flooding has recently occurred in the well area

Municipal wells: Drinking well water from municipal wells serving highly populated areas is considered safe because the water is tested for bacterial contamination more than two times each day.

Private wells and small community wells: The quality of well water from these sources cannot be guaranteed unless it is tested daily and found to be negative for coliforms and Cryptosporidium organisms.

It is recommended that other approved water sources be used instead, including: boiled water or bottled water (see guidelines below).

Not considered safe: Common home water filtration devices do not remove bacteria or viruses.  If the well water supply is chlorinated per guidelines provided by your local health department, the chlorinated water treated with one or more of the following is considered safe to consume:

• Reverse osmosis treated
• Distillation
• Filtered through an absolute 1 micron or smaller filter (NSF Standard #53 for cyst removal)
  See “Water Filters” (below).

Safe Water Sources
The following sources of water are suggested if your water is not from a city water or municipal well supply: 

• Boiled Water
  At home, safe water can be made by bringing tap water to a rolling boil for one minute.  After processing, the water should be stored in a clean, covered container in the refrigerator; discard water not used within 72 hours (3 days).
• Distilled Water
  Water may be distilled using a steam distillation system.  After processing, the water should be stored in a clean, covered container in the refrigerator; discard water not used within 72 hours (3 days).
• Bottled Water
  Acceptable forms of bottled water have been processed to remove organisms known to cause stomach or intestinal infection.  Bottled water labels reading “well water”, “artesian well water”, “spring water”, or “mineral water” do not guarantee that the water is safe to drink.  Water labeled as having been treated with one or more of the following are considered safe:
• Reverse osmosis treated
• Distillation
• Filtered through an absolute 1 micron or smaller filter (NSF Standard #53 for cyst removal)

To be sure that a specific bottled water has undergone one of the above processes, contact the International Bottled Water Association (IBWA) at 1-800-928-3711, or visit their home page at www.bottledwater.org.  If the IBWA does not have information on a specific brand, call the bottling company directly.

Members of the International Bottled Water Association (IBWA) follow more strict manufacturing practices in their water bottling process than those practices currently mandated by the United States Food and Drug Administration.  Therefore, water bottled by a member of the International Bottled Water Association may be preferable to water produced by non-member bottlers.

Water Filters
Most water filtration devices will not make the water safe if the water supply has not been previously chlorinated.  If you choose to install water filters on household water taps purchase only filters certified by NSF International. The following specifications must also be met:

a. The filters must be designed to remove coliforms and Cryptosporidium.  Any of the following are acceptable:

• Reverse osmosis filter
• Absolute pore size of filter 1 micron or smaller
• Tested and certified by NSF Standard #53 for cyst removal

b. The water tap filter must be installed immediately before the water tap
c. Manufacturer directions must be followed for filter maintenance and replacement

Portable water filters (such as a Brita® or Pur® system) as well as refrigerator-dispensed water and ice machine systems do not meet filtration standards.  Portable water systems filter out chemical impurities, not bacteria.  If a portable water system (such as a Brita® pitcher) is used in combination with a safe water supply (to improve water flavor and remove chlorine and other impurities), it is recommended to change the system’s filters frequently according to manufacturer’s guidelines.

For a list of approved filtration systems, call the National Sanitation Foundation International, at 1-800-673-8010 or visit their home page at www.NSF.org (go to the section entitled “Home Water Treatment Devices”).