Is Your Water Safe?

To limit exposure to MAP (mycobacterium avium subsp. paratuberculosis) and mycobacteria in general, I’ve researched ways to guard my home against these pathogens, via water. Unfortunately, most public water utility systems offer little protection from mycobacteria because of its ability to produce biofilm, which attaches to water pipes, both incoming and outgoing. “In fact, M. avium numbers increase in drinking water distribution systems as the distance from the treatment plant increases” (Joseph O. Falkinham III, Reducing Human Exposure to Mycobacterium avium, This risk increases since runoff from livestock and dairy farms, which likely contain mycobacteria and MAP end up in rivers, a source for public water supplies. Low heat temperatures and diluted chlorine are simply ineffective in destroying mycobacteria.

According to Dr. Falkinham, mycobacteria are common in the following: ice and water from refrigerators, basic water filtration systems, humidifiers including those in HVAC systems, spas, hot tubs and the like. He recommends disabling humidifiers in HVAC systems or not leaving water in reservoir, plus cleansing and disinfecting reservoir every 2 weeks, (the amount of time M. avium recolonizes).

Hot water heaters pose a looming threat and maintaining water temperatures of 130°F (55°C) or above reduces the growth of mycobacteria; buildings with water redistribution systems have higher counts of M. avium. To limit exposure consider the following:

-Routinely drain and refill hot water heaters every 2 weeks
-Open bathroom windows and use efficient ventilation fans
-Regularly disinfect your showerhead for 30 minutes in undiluted household bleach
-Exclusively use showerheads which produce water streams greater than 1 mm in diameter, or use shower heads with microbiological filters with less than 0.45 pore size

I was surprised to learn that most GAC (granular activated carbon) and AC (activated carbon) water filters offer no protection and may promote the growth of mycobacteria. Carbon is used in water filtration systems to eliminate odors and bad taste from chlorine, metals and minerals present in the water; this works through a process known as “adsorption.” Adsorption is where organics in the water being filtered, adhere to the carbon’s molecular bond.

Carbon filters have too large a pore size to trap biological impurities, including mycobacteria. The water is filtered at too fast a rate to catch the contaminants and the actual components (carbon) are not capable of keeping mycobacteria at bay (recolonizing every 2-3 weeks).

Since I’ve used carbon filters for years, I wanted to know the difference between a water filter and a water purifier; one main difference is the size of the contaminant each system allows through. Water purifiers mostly catch viruses; water filters have too large a pore size to catch viruses, both are ineffective in catching mycobacteria.

Dr. Falkinham recommends boiling water for 10 minutes to destroy mycobacteria, a practice I regularly follow for my drinking water!

Reducing Human Exposure to M. avium


wow – that is a great amount of information

These little known about sources can be big deals – I’m excited that you enjoyed the content. More on the way!

Judy Wanamaker

It is amazing how much I learn from you. In my 71 years I have never heard of this, although I have heard of people becoming ill after drinking contaminated water. Thanks for being such a wealth of helpful information, Krista. I hope you are doing better now. It is a little late, but Happy New Year. May you enjoy God’s greatest blessings this year and beyond.

Happy New Year to you! I’m happy that you found the info helpful; such massive amounts of knowledge to be found, stay tuned for more!

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