Recently I was asked about methods to treat your water while in the backcountry and thought it would make a good blog post. Here is the quick and dirty:
- Filters — The main advantage is they will remove all dirt, containments, and organisms. How well the filter works will depend to the physical size of the pores in the filter medium. If you have a filter you should understand the level that you are filtering to. Filters are generally heavier of the options. Different filters will have different attributes such as filter rate, method (pump, gravity fed), etc. You should understand how to repair the filter in the field.
- Chemical systems – Generally lighter and can kill most micro-organisms given appropriate time. Chemical systems are affected by temperature. Chemical systems will not remove dirt/debris or any other containments. Each chemical system has limitations and advantages. It’s worthwhile to understand the pros/cons of each or at least your system.
- UV kills organisms by shooting UV light into water given appropriate exposure time. With the steri-pen, you are limited to 1 liter at a time. UV is similar to chemical systems in that they do not filter dirt/debris or containments. Its effectiveness can be impacted by the condition of the water (muddy may not be as effective). For that reason, Steri-pen recommends use in clear water. Over longer periods or further in the backcountry, it may be good to have a back-up in case your device fails.
Notes from personal experience:
I mainly use Aqua Mira or boiling as I am usually most interested in an effective solution for the lightest weight. Some have complained of a slight after taste. I tend to use 5 drops per liter instead of the recommend 7 and I haven’t had any issues with taste. This is not recommended by the manufacturer so please consider your risk and make the best choice for you. If you are concerned about chlorine in the water, you may want to look at your local city water source as well.
Remember, a chemical solution isn’t always the right choice. I evaluate based on several factors including: equipment available, trip length, water sources, group size, temperature and weight. For example, what I would use in the Washington backcountry might be different than a remote village waterhole.
Most water in the backcountry of Washington has minimal debris and is relatively clean. Some would say it doesn’t even need treatment. I tend to take the more conservative approach and treat - especially during summer months. Many of our areas, especially ones where average hikers/backpackers/climbers go, are high-use areas. I know several people who have become ill from Giardia or Crypto or other waterborne organisms. What I can say is that the recovery process from these bugs can be extensive and most were sufficiently ill to regret not mitigating the risk. If you choose to not treat/filter, evaluate the risk and make a conscience choice. I don’t treat 100% of the time, but I don’t take the decision lightly. For certain, you can never be sure. For example, one group I know decided to drink from a stream in a very low-use area, only to walk upstream and find a dead elk carcass laying in the water. Clean upper mountain water is a matter of perspective. It depends on the mountain, your route, and time of year. For example, Mount Rainier sees around 1.7M people per year, with over ten thousand attempting to climb it. That’s a lot of poop. At high altitude, I often use rodents as an indication of use. I’ve camped at 13,300’ on Mt Rainier in the summer and there were still mice. There is only one reason for mice to be up at that elevation – people.
For someone starting out, the best advice I could give is: learn the options and risks so you can make informed decisions and have flexible options. What works for one person or situation may not work for another. Try not to attach to hard rules. No one solution is perfect for every situation. In addition to word of mouth, product information and searching the web can be useful resources. Everyone will have different experience and knowledge levels. Triangulate from multiple sources and then decide what’s best for what you need.
Have a good system you like you use? Leave a comment and share!