Troubling the Water

On August 31, 1854, an outbreak of cholera occurred along Broad Street (now Broadwick Street) in London. Over the next three days, 127 people living in the area died; the count rose to 500 a week later. Most of the nearby residents fled the area, fearing they would also be infected. Instead of fleeing with them, Dr. John Snow decided to investigate. He interviewed the families of victims, drew up a dot map of cholera occurrences, and his research pointed him to drinking water sourced from the Broad Street water pump. While government officials were not completely convinced by his findings, they agreed to remove the pump’s handle and prevent any more people from drinking the water. Shortly afterwards, the outbreak subsided.

Though germ theory wouldn’t reach scientific consensus until another decade or so after Snow’s work, we now know that cholera is caused by the waterborne bacterium Vibrio cholerae. Sanitization and waste management soon became a government priority, and treated, filtered drinking water became the norm, particularly in developed countries. About 90 percent of the world’s population today has access to safe, drinkable water – a major achievement. Therefore, it’s a bit concerning that there now exists a movement to get people to eschew treated (i.e. germ-free) water for so-called ‘raw water’.


Original map by John Snow showing the clusters of cholera cases (indicated by stacked rectangles) in the London epidemic of 1854. Image Credit: Public Domain.

Raw water is water that has not been filtered, treated, or sterilized. As such, it doesn’t contain chemicals that one may find in tap water, such as fluoride (added to prevent dental caries) or lead (found in outdated public water systems). Proponents say that raw water contains healthy and natural minerals that get stripped when water is treated and filtered. They also claim it contains probiotics, or beneficial bacteria, that supposedly promote a healthy digestive system. As one raw water connoisseur commented, her “skin’s plumper” and she feels she is “getting better nutrition from the food I eat”. While these claims might be plausible, or at least non-harmful, the rest of the raw water platform is just nauseating (which, coincidentally, is a symptom of cholera).

For instance, raw water proponents claim one does not need to worry about ozonation, a water treatment method, and how it changes the molecular structure of water. However, this is just bad chemistry. All water is composed of one oxygen atom and two hydrogen atoms. If you changed the molecular structure of water (e.g. added another oxygen atom), it would no longer be water. Even further off the deep end are the claims about irradiation, which is used to kill microorganisms. Proponents say it turns water into a GMO (i.e. genetically-modified organism). However, if not already obvious, water is not a living organism and does not contain genes. Therefore, you cannot genetically modify it.

But, these erroneous claims are not the most dangerous things about raw water. One ‘natural’ additive often included in untreated water is human and animal waste, which contains disease-causing bacteria (like those that caused the cholera outbreak in 1854). Pesticides and heavy metals are also common water contaminants. Drinking raw water could literally be life-threatening.


Scanning electron microscope image of Vibrio cholerae bacteria. Image Credit: Ronald Taylor, Tom Kirn, and Louisa Howard.

Clearly, the pseudoscience driving the raw water movement is not just laughable, but dangerous to those taken in by it. The work of John Snow, and later epidemiologists, showed just how hazardous untreated water could be; governmental water sanitation systems have since saved countless lives. That said, raw water is also a huge waste of money. For all the ‘benefits’ of raw water, people are paying upwards of $36.99 for 2.5 gallons. Tap water from the public water system in Athens, Georgia costs less than one cent a gallon; that’s 3400 times cheaper than raw water. Raw water drinkers would probably be best served by skipping on this latest ‘health’ fad and sending their money to help develop safe water sources for the 663 million people who still have no choice but to drink unsafe ‘raw water’.

About the Author

A transplant from Virginia (Hoos!), Greg Evans is a graduate student in the Plant Biology department at the University of Georgia studying herbicide and herbivory defenses in morning glories. When he’s not tangled up in weeds, Greg enjoys Ultimate Frisbee, bowling, and board games. He can be reached at More from Greg Evans.