By Kelly A. Reynolds, MSPH, PhD

Water treatment professionals may not have seen this coming but the new ‘raw water’ trend is making headlines around the US and beyond. Proponents of the trend, which encourages consumption of untreated water, claim it’s a healthy alternative to processed water. Others recognize consumers of raw water as misinformed targets of a dangerous fad.

Raw water
By definition, raw water is water that hasn’t been treated or processed in any way. Existing in its natural form, without the use of filtration to remove impurities or chemicals to inactivate potentially harmful microbes, the product is being marketed as a new health initiative and is growing in popularity.1 According to raw water proponents, water that is not processed in any way retains good bacteria (or probiotics) that can reduce illness and improve skin tone. The product reportedly has a limited shelf life before turning green—a property that treated tap water, referred to as dead water by raw water fans, doesn’t have (thankfully).2 While not exactly mainstream, several companies have emerged in the US offering unfiltered, untreated, unsterilized spring water averaging over $14 a gallon with a glass container and $6 a gallon for refills. The product is flying off the shelves as sales continue to increase.

The raw water trend is reminiscent of the increasing interest in raw, unpasteurized milk, touted as a natural, healthy food with improved taste. Similarly, raw milk proponents claim benefits of reduced allergies and asthma, while building better immunity to fight infections. These claims have not been substantiated via controlled scientific studies.3 Rather, raw milk consumption is linked to numerous foodborne outbreaks, from bacteria such as Listeria, Salmonella, E.coli and Campylobacter. In fact, since 2007, outbreaks from raw milk have been increasing in the US despite associated severe illnesses and deaths, and the fact that sale of raw milk across state lines is prohibited by the FDA. Although states may retain the right to sell raw milk within their borders, approximately 20 prohibit such actions.

In addition to misconceptions regarding the health benefits of raw water, there is an increasing mistrust of government-supplied drinking water following recent reports of drinking water treatment failures, including the Flint, MI debacle. Further, consumers have spent decades debating the pros and cons of adding chemicals, such as fluoride and chlorine, to municipal water supplies, which can produce harmful effects. These concerns have led some to seek what is perceived to be a more back-to-nature approach to drinking water.

Pure H2O doesn’t have any taste and is often described as flat and not too appealing to drink. A common practice in the bottled water industry is to strip source water of nearly all impurities, including beneficial minerals, only to add them back in to improve taste and health benefits. Salts and minerals (like sodium chloride, potassium, calcium and magnesium) are often present in nature as part of rocks and soil and persist in trace amounts in drinking water sources; they may be added back in to bottled water. Our bodies need these electrolytes, found in food, sports drinks and water, to function properly. Production of water through a controlled treatment mechanism is a safer approach to better health.

Untreated water risks
All US community water systems are required to monitor for regulated water contaminants and produce an annual consumer confidence report. These reports contain information about the local drinking water source, risks of contaminants, detection of any regulated contaminants (and their potential health effects if detected above recommended levels), actions taken to restore water quality and other educational information, including increased contaminant risks to vulnerable populations and information about specific regional concerns, such as lead.

Natural waters frequently contain harmful waterborne contaminants that are unnaturally present, such as Cryptosporidium protozoa or nitrates from cattle feces or other agricultural operations, Shigella bacteria from human wastewater intrusion or cyanide leachates used in mining operations. Other water contaminants are completely natural to the environment but still harmful, such as arsenic, uranium, radon and manganese. Another problem with the raw water movement is that the water source, although typically a natural spring, may not be properly vetted and approved as safe.4 Water from even the most pristine areas could be contaminated by wild animals and rain/land runoff. (My mentor, Dr. Charles Gerba, University of Arizona Professor, used to always say: “Every stream is a beaver’s latrine”).

Worldwide, more than half a million deaths are attributed to untreated drinking water exposures every year.5 Treatment of drinking water, which has been considered one of the greatest public health advances of the century, virtually eliminated scourges of cholera, typhoid and dysentery that dramatically reduced US life expectancy in the early 1900s. Today, we don’t think about the risks prior to the water treatment advances that are credited with adding decades to our current life expectancy.  As one commentator points out: “There is a reason that everyone, including children, drank so much hard cider and beer during the 1700s and 1800s: because waterborne illness was prevalent and alcoholic beverages were safer than many sources of raw water.”4

Benefits of water treatment
While failures in municipal water treatment do occur every year in the US, exposing millions to waterborne contaminants, the risks of drinking untreated water are substantially higher. Both naturally occurring and introduced hazards are commonly detected in source waters Therefore, treatment consists of a multi-barrier approach, designed with overlapping redundancies, to target a variety of pollutants including microbes, chemicals, heavy metals and metalloids, and physical and aesthetic contaminants. Redundancy in the system is intentional in case one barrier fails, creating the need for an additional barrier to compensate.

The first barrier in community water treatment is source-water protection. Sources are selected from sites where risks of contamination are minimized to reduce the need for other treatments. The second barrier involves managing contaminant risks via treatment designed to meet federal drinking water standards at the municipality and in the distribution system. The third barrier is monitoring to ensure compliance with federal standards and to recognize any deficiencies in the treatment or distribution networks. The fourth barrier includes consumer education and notification of any potential health risks or source substitution needs (i.e., boil-water alerts) and the expectation that consumers become partners in ensuring water quality by reporting any concerns.

Other individual actions may be referred to as the final barrier, where consumers are generally responsible for drinking water treatment at the point of entry or point of use. Treatment at the tap offers protection from any previous treatment barrier failures and perhaps the only barrier for contaminants entering the system via the municipal or building distribution or plumbing network.

For anyone concerned about the presence of contaminants in, or addition of chemicals to, water, a POU treatment system provides a final barrier of protection. In terms of the potential benefits of probiotics, vitamins and minerals, the best way to consume these products is through properly regulated food, supplements and treated drinking water sources and not from an uncertain raw water source.


  1. Tanner C. Drinking raw water trend is potentially deadly. Daily Mail Online. Published January 4, 2018. Accessed January 20, 2018.
  2. Bowles N. Unfiltered Fervor: The Rush to Get Off the Water Grid. The New York Times. Published December 29, 2017. Accessed January 20, 2018.
  3. David S.D. Raw milk in court: implications for public health policy and practice. Public Health Rep. 2012;127(6):598-601. doi:10.1177/003335491212700610.
  4. Manganaro C. Why the raw water movement is so obnoxious. Slate. January 2018. Accessed January 20, 2018.
  5. WHO | Drinking-water. World Health Organization. 2017. Accessed January 20, 2018.

About the author
Dr. Kelly A. Reynolds is an Associate Professor at the University of Arizona College of Public Health. She holds a Master of Science Degree in public health (MSPH) from the University of South Florida and a doctorate in microbiology from the University of Arizona. Reynolds is WC&P’s Public Health Editor and a former member of the Technical Review Committee. She can be reached via email at [email protected]


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