Boil Water Advisories: Managing Pathogen Risk in Buildings

Boil Water Advisories: Managing Pathogen Risk in Buildings

By Hilary Nardone, MPH, Environmental Group Training Manager
Certified ASSE 12080 Legionella Water Safety and Management Specialist 

Municipal Water Utilities or local health officials may issue boil water advisories when bacteria such as E. Coli are identified in the community’s drinking water.  E. Coli are bacteria whose presence indicates that the water may be contaminated with human or animal wastes.  Human pathogens in theses wastes can cause short-term effects, such as diarrhea, cramps, nausea, headaches, or other symptoms.  They may pose a greater health risk for infants, young children, the elderly, and people with severely compromised immune systems.

Picture via CDC

During a boil water advisory, it is expected that less water will be consumed than during times of normal operation.  This could lead to stagnation in water distribution piping which, in conjunction with loss of disinfectant and disruption of biofilm, may make building water systems more susceptible to Legionella bacteria growth and amplification.  Legionella bacteria are the causative agent of Legionnaires’ disease, a pneumonia-like illness that is transmitted to humans via aerosolized water droplets that are contaminated with Legionella bacteria.

In addition to following your facility’s Emergency Water Supply Plan, taking small practical steps at your facility can help minimize the risk of coliform, E. Coli and Legionella bacteria contamination in your drinking water systems. Per the Centers for Disease Control and Prevention (CDC), the following are some control measures to take at your facility when a boil water advisory is lifted:

  • Flush, clean and sanitize equipment with water line connections per manufacturer’s instructions.
  • Flush pipes, faucets and drinking water fountains for at least 5 minutes.
  • Drain and refill hot water heaters set below 113°F.
  • Change all point-of-entry and point-of-use water filters, including those associated with equipment that uses water.


Barclay Water Management, Inc. can assist your facility with coliform sampling, Legionella bacteria sampling, and ice machine cleanings as proactive measures and validation of these action items at your facility.  
Barclay works with third-party, CDC ELITE and drinking water-certified labs to provide our customers with coliform, E. Coli, and Legionella bacteria results, along with result interpretations and relevant recommendations.   Contact Barclay now for assistance and scheduling.


Additional resources on Boil Water Advisories can be found in the following pages:
Boil Water Advisory | Water, Sanitation, & Hygiene-related Emergencies & and Outbreaks | Healthy Water | CDC
Hospitals, Healthcare Facilities, & Nursing Homes | Cryptosporidium | Boil Water Advisories | CDC
Boil Water Notices – Frequently Asked Questions for Hospitals and Other Resident Medical Facilities (ny.gov)

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