Possible pathogens in rainwater harvesting tanks

Just came across this article entitled “Rainwater harvesting tanks enable spread of dangerous pathogens, study shows”.  The article describes a fairly straightforward set of findings from rainwater storage tanks in South Africa.  Researchers found Legionella, Klebsiella, Giardia, Salmonella, and Yersinia.  Not a friendly-sounding list of bugs.

However, I have the usual set of issues with this.  Firstly, there are plenty of species/strains in all these taxa that are totally harmless… so we don’t know much beyond the *potential* for pathogens in the system.  Secondly, the claims from the title are clearly overblown, simply finding these taxa in the tanks doesn’t mean that the tanks are “enabling the spread of dangerous pathogens”.

I’d look for more detail in the actual research article but the link takes to a closely related paper on E.coli in rainwater by the same group and I haven’t found the correct source paper yet.

Also missing is a discussion of the tradeoffs between drinking this potentially contaminated rainwater from storage and drinking untreated water from potentially much worse sources.

Photo credit: Susan Buffler

One thought on “Possible pathogens in rainwater harvesting tanks

  1. There have been a number of outbreaks and epidemiological studies associating various diseases with rainwater tanks. A good amount of work in Australia. Scant work in N. America. I have a doctoral student actively working on this topic.

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David Coil

David Coil is a Project Scientist in the lab of Jonathan Eisen at UC Davis. David works at the intersection between research, education, and outreach in the areas of the microbiology of the built environment, microbial ecology, and bacterial genomics. Twitter