Studies have shown that many building water systems in the United States are contaminated with potentially harmful bacteria and, in fact, disease outbreaks which can be traced to contaminated water happen with incredible frequency worldwide affecting thousands of people.

In some cases, it is actually possible to trace the origin of an illness (infection) to an exposure from a specific water source. Much more frequently however, people get sick from water and have no idea what, where, or how they got impacted.


Consequently, potentially contaminated buildings and/or parts of those buildings are often shut down as a result of these occurrences as experts race to find the source and extent of the problem and subsequently provide some treatment methodology.
Waterborne Pathogen Contamination

Solving a potential issue of water contamination however is a very complex problem starting with the fact that some building water systems can literally be miles long, are inaccessible, very old, and the water flowing into these systems from municipalities may already be contaminated with chlorine tolerant pathogens.

Furthermore, many of the worst pathogens thrive within difficult to remove/penetrate biofilms within building water systems and are resistant to cleaning efforts.

And to make matters ever more confusing, while there is general consensus among organizations such as the CDC, OSHA, ASHRAE, and state health departments with respect to what methodologies and/or technologies are most proficient at responding to an emergency outbreak event, this consensus completely falls apart when the issue becomes how to PREVENT the likelihood of recurrence going forward.

The latter issue is termed secondary disinfection (unlike emergency disinfection) and is the process whereby a water system or some part thereof may be disinfected on a continuous basis after an emergency exposure has passed.

Investigating Waterborne Pathogen Outbreaks

Unfortunately, a quick investigation of recent outbreaks linked to waterborne pathogens will yield a wide variety of recommended secondary disinfection methodologies each of which is touted with their benefits and critiqued with their detriments with no clear winner and no real recommendation for what to use when.

While few would dispute that each of the water pathogen eradication technologies have their benefits as well as their shortcomings, to the best of my research and knowledge, there has NEVER BEEN A SINGLE side by side (apples to apples) comparison test ever performed of these various strategies anywhere in the world.

What makes this all the more incredible is that PREVENTION is the mantra of infection risk today – both for healthcare as well as the general population.

In addition, the pathogens that frequently become embedded in our water systems include some of the most notorious illness producers- acinetobacter, legionella, and pseudomonas to name just a few. And so when outbreaks occur which can be traced to a particular water system and all the experts are brought in, there is generally little agreement with respect to how to maintain the water quality to PREVENT future occurrences.
Responding to Waterborne Pathogens

We know how to respond to these occurrences on an emergency basis and can usually reduce exposure risk after surveillance has identified an issue. We just do not have information on comparative efficacies for ongoing contamination prevention which is why waterborne pathogen based outbreaks continue to occur and have actually significantly increased in the last 10 years.

Methodologies such as chlorine dioxide, monochoramine, copper-silver ionization, chlorination, and others all have their champions but what is sorely needed is a head to head comparison so that facility experts, infection preventionists, healthcare organizations, etc. can make appropriate informed PREVENTION based decisions with respect to what system should be employed when and where.

It is difficult to understand how anyone can malign and/or endorse any single secondary disinfection methodology until such a comparison test can be documented.

Sadly, until such time, outbreaks will continue to occur, improper methodologies will be employed utilizing technologies that may not be appropriate for the risk at issue, resulting in a colossal failure to prevent significant pathogen exposure.