The world of backcountry water filters is a surprisingly scary one. As someone who鈥檚 had giardia and听norovirus听and picked something up in Peru 15 years ago that may still be hanging out in my intestines, I can tell you that the stakes are high.听There is no听governing body regulating the efficacy of physical filters. (The FDA approves only听chemical water purification products, like or iodine tablets.)听Though there are testing standards for water filters used by the military鈥擨 highly suggest looking into ,听which some brands use鈥攖hey are not mandated for civilian products.
Without a unified standard, it鈥檚 important to be careful and do your research听when purchasing a filter. But if you want to skip those steps, I suggest the . I鈥檝e used it to purify hundreds of gallons of water, and it鈥檚 ideal for group pursuits in the backcountry or in emergency scenarios.
In September, my wife, my three-year-old daughter, Jojo, and I evacuated when southern Oregon鈥檚 Almeda Fire started less than a mile from our home. My wife and Jojo took off immediately while I stayed to pack up the important papers, the most treasured stuffed animals, and听the听GravityWorks system. I was driving off into a lot of unknowns that morning, but I can鈥檛 overstate how comforting it felt to throw the filter听into my car over the haphazardly packed suitcases. The fear of not knowing whether we鈥檇 come back to a standing house (we were the lucky ones who did) was significantly mitigated by the knowledge that听we鈥檇 at least have access to drinkable water as long as we could find a spot by a river. That peace of mind听is priceless.
The GravityWorks 4.0 is remarkably easy to use. I got my first one听in May 2014 and couldn鈥檛 believe I hadn鈥檛 made the investment previously. I was notorious among my kayaking buddies for how reckless I was with my gut fauna as a young man, which really caught up with me in my mid-twenties (see: intestinal distress rap sheet above). Once I started using this model, I couldn鈥檛 believe how much diarrhea, vomiting, and general malaise I had put myself through to avoid the simple three-minute process of filtering my water. The design is so straightforward that I would trust filtering my water to a precocious third grader. Simply fill the clearly labeled 鈥淒IRTY鈥 bladder with unfiltered water, elevate it above听the 鈥淐LEAN鈥 one, and make sure the filter arrow marking the 鈥淔LOW鈥 of the filter is going from 鈥淐LEAN鈥 to 鈥淒IRTY.鈥 That鈥檚 it.
The GravityWorks 4.0听also filters water lightning-fast,听which听makes it great for groups. This filter takes about a minute to set up and goes through more than 1.5听liters per minute. (Multitasking is easy if you find the right tree branches to hang the bags on.)听I can filter听water for several people听(and pound a liter or so myself) in under 20 minutes whenever we reach a water source. With this system, I took my in-laws on their first backpacking trip in the summer of 2014 and kept everyone in our听seven-person group听hydrated and equipped with cooking water with very little听effort on my part. While you can find lighter filters out there鈥攖his one is听almost 12 ounces鈥攖he extra weight is worth it when you need to clean a lot of water.
But it鈥檚 the least noticeable feature of this filter that鈥檚 the most important. It meets all EPA and NSF guidelines to remove bacteria and protozoa, though there is no legal requirement for filters to do so. This means I don鈥檛 have to stress about getting a nasty bug if I use it stateside. (It doesn鈥檛 filter out viruses, like chemical treatments and my international-trip听favorite, the听听($350), but pretty much any water I am going to filter from in the United States听is not likely to have those issues.) That level of trust is key when dealing with a resource as precious as water.