Gadgets

UV Water Purifiers Are Bullshit

UV Water Purifiers Are Bullshit

To achieve its claimed ability to remove pathogens, water going into CamelBak’s new UV purifier must first be cleaned by a filter from a rival manufacturer. And that rival product is cheaper. That’s according to CamelBak’s own lab testing. And its not the only water treatment technology that’s incapable of performing as claimed.

This failure to perform as advertised is symptomatic of a larger issue. Water treatment for the outdoors is not regulated. Consumers are unaware of the efficacy of water treatment products as a result and are actively misled by marketing claims from the companies that make them.

UV Water Purifiers Are Bullshit

“Reducing bacteria by 99.9999 per cent, viruses by 99.99 per cent and protozoan cysts by 99.9 per cent, All Clear purifies water not only to stringent EPA standards, but to CamelBak’s uncompromising standards of safety and performance,” reads the claim about the All Clear UV purification bottle on the brand’s website.

Yet, an independent lab commissioned by CamelBak to test these claims found that, while the filter was effective at killing those three pathogens, it was only capable of doing so in clear water. The lab performed the de rigueur turbid water test by first passing the water twice through an MSR filter. That product removes dirt, protozoa and bacteria on its own, so it’s no surprise that testing found that stuff to be gone after also being treated by CamelBak’s UV light. The effectiveness of the All Clear in non-filtered turbid water was not tested.

UV Water Purifiers Are Bullshit

CamelBak itself acknowledges this disparity, specifically instructing users to employ an $US89 MSR Miniworks EX filter to clean dirty water before it goes into the $US99 All Clear purification bottle. The trouble here is that the claims of its efficacy are bold and prominent, while the instruction to use that MSR filter is buried deep in the small print.

And you know what? Not only is that MSR filter a few bucks cheaper, but it also doesn’t require batteries, won’t break if you drop it and removes all the dirt the CamelBak doesn’t. CamelBak instructs users to fill the All Clear only with clear water. “If it’s thicker than lemonade,” they say to filter it first. I want to know what kind of lemonade they’re talking about!

UV Water Purifiers Are Bullshit

Water turbidity is measured in NTUs; 5 NTUs (above right) being the most turbid water a UV purifier like the CamelBak is able to treat. That’s some very weak lemonade!

One of the confusing things going on here is that there’s different kinds of gross stuff in water. Let’s start with the dirt itself, which is a major problem for the CamelBak. They need the MSR filter to remove it because, in using UV light to kill bugs, you need the light to hit those bugs. If they’re hiding in the shadow of a piece of dirt when that light passes through, the All Clear won’t work. The dirt particles are large in comparison to tiny viruses, which are so small they can pass through the holes in most filters, but there’s still millions and millions of dirt particles in turbid water.

What the All Clear and other UV purifiers can do that most filters can’t is kill viruses. But only once the water is clear enough for the light to reach them. Viruses aren’t actually a huge issue for most outdoor enthusiasts. At least not here in North America. It’s really only if you’re travelling in third world countries that you should worry about Hepatitis A, Norovirus and other viruses. The CDC recommends you treat water you suspect of carrying viruses with chlorine dioxide or by boiling it. Chlorine dioxide tablets are cheap, proven and additionally remove protozoa and bacteria, which you’ll encounter far more commonly.

If you’re travelling to a country where the tap water may contain viruses, then a UV purifier like the All Clear will be an effective way to remove viruses and other pathogens from clear tap water. If you simply want “purified water anywhere,” as CamelBak’s marketing copy in the top shot (pulled from their website) suggests, then the All Clear and other UV purifiers are not a good option, they will not work in any water that is not clear.

“Purified water anywhere?” Bullshit, CamelBak.

CamelBak isn’t the only company guilty of misleading consumers about the efficacy of water treatment products. Sawyer famously advertises “1 million gallons guaranteed,” for its inline filters. There’s two problems with that: one in the small print and another in real world testing.

Sawyer’s small print reads: “We didn’t actually run a million gallons through the filter because that’s a lot of water.” It sure is! And that’s probably why rival brand Katadyn asked the National Advertising Division of the Better Business Bureau to look into it.

“NAD found that the million-gallon claims conveyed a message of indestructibility and longevity that was not supported by the evidence on record,” they concluded in January. “NAD recommends the advertiser discontinue such claims.”

UV Water Purifiers Are Bullshit

At the time of writing, the “1 Million Gallon Guarantee” can still be found on Sawyer’s US website, where it’s featured prominently, and in the descriptions of its products on Amazon. Consumers are still being misled.

And there’s proof that Sawyer’s inline filters suffer from service life far shorter than claimed. A field study conducted by Tufts University School of Engineering found that the filters’ ability to remove pathogens began to reduce after just two months of frequent use and fell from a 99.999 per cent effective rate when new to removing just 54 per cent of E. Coli bacteria after 23 months of regular use. In case you’re not aware, E. Coli comes from poop. The filters are allowing 46 per cent of poop bacteria through before they’re two years old.

UV Water Purifiers Are Bullshit

Sterile, clean water went in to used, but cleaned Sawyer filters. This is what came out. Yes, there’s faecal coliform in there.

The Tufts study was conducted on a sample of Sawyer Point One filters installed in a Honduran village by charity Pure Water for the World. Those filters require “backwashing” and other simple maintenance, which the villagers say they performed to spec, but to eliminate that variable, the researchers pulled six used filters and cleaned and backwashed them themselves. They then ran sterile water through them to see if built up crap inside would pollute it. They found that faecal coliform was introduced to the sterile water by the filters. The ones that still allowed water to pass through, anyways.

They also cut the filters open, where significant visual degradation was observed and looked at them under a microscope, where they observed significant membrane fouling.

“…Sawyer PointOne filters were found to have low bacterial and turbidity removal rates after 23 months of household use,” the study concludes. “When sterile water was introduced, it exited these filters with higher turbidity and bacteria loading. At least one membrane was irreversibly fouled on interior and exterior membrane surfaces. One filter appeared to have burst fibres, potentially allowing short-circuiting of water.”

Here in California, the average household uses about 170 gallons (66=44 litres) of water a day indoors. That’s likely way, way more than is being used by a household in rural Honduras, but let’s just use that as a worst case scenario. Two years of that water use is 124,100 gallons (469,770 litres). And Sawyer’s filters are being shown to fail before they’re two years old. Now I’m not very good at maths, but 124,100 is a lot less than one million, right?

Sawyer’s “1 Million Gallon Guarantee?” Also bullshit.

We reached out to both CamelBak and Sawyer for comment, but have yet to hear back.

UV Water Purifiers Are Bullshit

The moral of the story for outdoorsmen is that you need to think critically about the water treatment system you use. Your health relies on its ability to remove pathogens from water and you can’t trust the marketing claims, so you’ll have to educate yourself about what risks you face in the environment you’re operating in and the best ways to ameliorate them.

If you decide to use a filter, make sure it’s one with a positive end-of-life indicator. It should either clog up as it wears, with no way dirty water could ever enter your water supply, or come with some sort of prominent, idiot-proof wear indicator. Beware adsorptive filters, they may not remove all pathogens as they pass through and water continues to flow through them well after their filtration abilities are worn out. Take the time to learn how your filter works and use it properly.

If you chose to use a chemical treatment, follow its instructions, which typically involve proper dosage for the volume of water being treated and a period of time you’ll need to wait after treatment for them to take effect. If you’re dropping a chlorine dioxide tablet into a water bottle, for instance, you’ll need to “wash” its threads and mouth with treated water to remove any potential contamination from dipping it in a stream.

UV filters only work well in clear water, as CamelBak so helpfully demonstrates. They’re also electronic gadgets, which are prone to failure due to damage, vibration, battery failure or even water intrusion. While they are capable of killing viruses, there is no way to know if they have effectively cleared your water of them. While many water sources in the outdoors are very clear, even a minimal turbidity could skewer UV’s effectiveness.

Or, just do what the CDC recommends and bring any water to a roiling boil for at least one minute. That kills everything. Filtering it ahead of time will remove dirt, foreign particles and any gross stuff first.


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