Any system through which water courses is prone to microbial growth. The interaction of the water with the material, plus the water’s own bacterial content, and a bunch of other variables are responsible. Since this type of growth is pretty much a natural occurrence (plus, it’s easily concealed and contained within the system), people have the tendency to discount the harm it can cause and refrain from doing anything to prevent further proliferation.

Microbial growth in closed circuit systems is actually a big concern and people should address it right away – it not only compromises the integrity of the system, but it also poses health risks on end users, who happen to be the people getting their water from the system. Microbes are composed of different types of bacteria, and here’s the deal: Most of them can easily be found in the system. You have aerobes which are bacteria that proliferate in the presence of oxygen (e.g., Pseudomonas), and then there are facultative anaerobes which are bacteria that grow with or without oxygen (e.g., E. coli), and there are also anaerobes which are bacteria that grow without oxygen (e.g., sulfate reducing bacteria).

With the first type of bacteria, the grave concern about its presence in a closed circuit system that delivers water is that it can cause serious health risks. Pseudomonas is a type of bacteria that can lead to a number of infections, some of them being minor ones like swimmer’s ear and hot tub rash. However, for already ill and weak folks, like the elderly, exposure to the Pseudomonas bacteria may prove to be deadly and really hard to treat because Pseudomonas resists common antibiotics.

The second type of microbe found in biofilm that grows in closed circuit systems is the facultative anaerobe E. coli. An E. coli infection is known to cause severe anaemia and kidney failure. E.coli bacteria transfer easily from water sources that may have been exposed to human or animal feces through water systems.

And the last one is the anaerobe sulfate reducing bacteria; their detrimental effects are on the structure itself. Metal components which are commonly used for closed circuit systems may easily corrode due to exposure to the bacteria. It’s been determined that “…interaction of water and metal creates a layer of molecular hydrogen on the metal surface; sulfate-reducing bacteria then oxidise the hydrogen while creating hydrogen sulfide, which contributes to corrosion.” Likewise, anaerobic activity by SRBs create a really funky “bad eggs” odour and can degrade chemicals added to the system. Closed circuit systems are by no means cheap to construct, hence it’s crucial that microbial growth within the system is prevented or addressed right away.

These are just some of the dangers imposed by microbial growth in closed circuit systems, but they are all very serious concerns. All these promote one fact: the importance of effective water treatment and thorough cleaning of water systems. By going about these tasks properly, the dangers and all other negative impacts can be minimised or thoroughly prevented.

+Duncan Hollis