The Why, What, Where of Boil Water Advisories

Posted on December 10, 2013

What you need to do during a boil water advisory, why you have to and where you can find out the information to keep your family safe from water pathogens.

What are some of the instances where you have to boil water?

This list created by The Department of Environment and Conservation  is a pretty pervasive and persuasive reason to boil water.  (And yet another reason to get a UV water disinfection system).

  • Water supply has no disinfection system
  • Chlorination system is turned off by the operator, due to taste or other aesthetic considerations.
  • Chlorination system is turned off by operator, due to perceived health risks.
  • Chlorination system is turned off by operator, due to lack of funds to operate.
  • Disinfection system is off due to maintenance or mechanical failure.
  • Disinfection system is off due to lack of chlorine or other disinfectant.
  • Water distribution system is undergoing maintenance or repairs.
  • A cross connection is discovered in the distribution system.
  • Inadequately treated water was introduced into the system due to fireflows, flushing operations, interconnections, minor power outage or other pressure loss.
  • Water entering the distribution system or facility, after a minimum 20 minute contact time does not have a free chlorine residual of at least 0.3 mg/l or equivalent CT value.
  • No free chlorine residual detected in the water distribution system.
  • Insufficient residual disinfectant in water system primarily disinfected by means other than chlorination.
  • Total coliform detected AND repeat samples cannot be taken as required
  • Escherichia coli (E. coli) detected AND repeat samples cannot be taken as required
  • Total coliforms detected and confirmed in repeat sample.
  • Escherichia coli (E.coli) detected in an initial sample(s) is considered extensive and the water system has other known problems.
  • Escherichia coli (E.coli) detected and confirmed in repeat sample.
  • Viruses detected (eg, Hepatitis A, Norwalk).
  • Protozoa detected (eg, Giardia, Cryptosporidium).
  • Water supply system integrity compromised due to disaster (e.g. contamination of water source from flooding, gross contamination, major power failure, etc.).
  • Waterborne disease outbreak in the community.

How to boil water

Sounds silly, right?  Make sure you boil water in a rolling boil for one minute minimum and three minute’s minimum if you are in altitudes above 2000 sea-level.  If you have baby formula make sure you sterilize all baby implements like bottles, nipples, etc. for two minutes and generally do not put the water through your coffee maker without boiling it first and coffee makers rarely boil water and let’s be fair, sometimes the contamination is sewage and while Kopi Luwak is expensive and popular – this stuff could make you sick.  Don’t forget to boil water for your pets too.

You already drank the water?

Well, watch for signs of vomiting, diarrhoea, and any upsets.  You may be fine but watch for any symptoms and get medical help. More info from the CDC.

How to find out about boil water advisories near you

Alerts go to the media, institutions like schools and hospitals, restaurants, etc.  Restaurants are given specific orders from Health Units. Check with your State, Province, Locality, to see just how to get this information and/or sign-up for Google alerts - just put in “your city/town boil water advisory” and watch your email account.  Canada also has a great website:   In the US, places like The City of New Orleans the Mayor’s office sends out Press Releases, check with your local agencies for more information.

Boil water advisories don’t affect me, right? 

Wrong! Actually not true.  It can happen anywhere at any time especially with aging infrastructure.  See this nice infographic from The Royal Bank of Canada’s 2013 Canadian Water Study Attitudes  – the data is shocking.

 Royal Bank Water  Infographic 2013