My AT Thru-Hike Water System

I shouldn’t have any trouble finding water on my Appalachian Trail thru-hike because what I’ve heard, there’s an abundance of it from natural sources such as streams, springs, and ponds. Many of these water sources look crystal clear and enticing enough to drink directly from them, and despite several claims from past thru-hikers that they did just that and never got sick, it’s not recommended that you do so. And even if you were able to drink directly from these water sources, you would still want a way to carry water so that you have a store of it for drinking between water sources and to have at camp at the end of the day.

You’ll see thru-hikers treating and storing water in many different ways. For storing water, one common way is to use a hydration reservoir, which is a water bladder that hangs inside your backpack with a tube connected to it that comes out of the backpack and basically wraps over one shoulder. On the other end of the tube is a bite valve allowing backpackers to drink water from it while they hike. Another common method is to have a number of water bottles that are stored in the outer side pockets of the backpack and often in a pouch on the shoulder strap. For treating water, there are chemical treatments, ultraviolet devices, filters, and boiling.

I have tried many different ways of storing and treating water and have settled on one that I think will work best for me on the AT.  I’m going to have a single, two-liter collapsible water storage bag that I’ll fill up from the water source. This bag will be my dirty water bag and I will never drink the water directly from it.

In addition, I’ll have three 700 ml Smartwater water bottles. One will be stored on my shoulder strap for easy access while I’m hiking. The other two will be in the outer side pouches on both sides of my backpack. I like these particular bottles for several reasons:

  • They are a nice size and weight for storing on my shoulder strap, in my pack, at camp, and in my tent.
  • The flip-top cap makes it easy to drink from when hiking. You also don’t have to worry about losing the cap due to it always being connected, unless it breaks, which is why I have a spare cap. And the cap fits onto the Sawyer Squeeze for back flushing, which is something that needs to be done every so often.
  • Smartwater water bottles are lightweight, durable, and relatively inexpensive.
  • Unlike the bladder reservoir systems that I have tried, the water bottles are not generally stowed inside the backpack, so you can easily keep track of how much water you have, and you don’t have to deal with disconnecting and unpacking it from the pack. And there is a significant weight savings by using the bottles.
  • The Smartwater bottles also work nicely with my filtration system.

700 ml Smartwater Bottle

Even though I have four containers for storing water, each liter of water weighs two pounds, which is over eight pounds of water I would be carrying when all containers are full. I certainly don’t want to be carrying that much extra weight if I don’t need to, so I will only fill up what I will need between water sources or for camp at the end of the day.

Instead of treating my water with chemicals, I’ll be filtering my water using the Sawyer Micro Squeeze water filter. The Sawyer Micro Squeeze weighs only two ounces and fits in the palm of my hand. While small in size, the powerful Micro Squeeze removes 99.99999% of bacteria (salmonella, cholera and E. coli) and 99.9999% of protozoa (cryptosporidium and Giardia). The Micro Squeeze is supposed to be able to filter 100,000 gallons of water before needing to be replaced. The filtered water typically is clear and tasty. My dirty water bag will screw onto one end of the water filter and, with the aid of a coupler, an empty 700 ml Smartwater bottle will screw onto the other end. The dirty water is then squeezed through the filter into the water bottle. It is also possible to hang the system and let the water get pushed through the filter by gravity, though it may take several minutes to do so.

filtering water


In the event that my water filter fails on me for some reason, I will be carrying a small amount of Potable Aqua Tablets that will chemically treat my water until I can get my filter replaced.

At times, the water source might be shallow or just a trickle, making it difficult to fill up the dirty water bag. For these situations, I have a cup, made from the bottom of a generic water bottle, that I’ll be able to use to scoop up water and then pour it into the dirty water bottle. The plastic that the cup is made from is lightweight and can be squashed flat for storing without cracking, and easily reforms back into a cup when needed.

water scoop cup

It’s always nice to have a water source that is near the shelter that you are staying at. Many of the shelters have water sources nearby and that is one consideration that I took when planning which shelters I wanted to stay at. Both of my trail guides, the 2018 northbound AT Guide and the Guthook app, show water source locations. In addition, the Guthook app also allows users to inform other users of the conditions of water sources. These guides will be very useful in determining how far away water sources are and how much water I will need to carry between water sources.

As of this writing, there are only 27 days till I hit the trail. I still have quite a bit of preparations left to do and I’m trying to get in practice hikes almost every day now. I might manage to get another blog post out before I leave, but I can’t make any promises. If not, you’ll be hearing from me on the trail.

So, until next time, happy trails.

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Comments 9

  • Pete Reich : Mar 13th

    Looking forward to reading about your trip. I have aspirations to complete it one day myself. So far I’ve sectioned over the past 4 yrs from Springer to Troutville.

  • mike rachelson : Mar 13th

    Looking at two of your photos, I believe you have the filter direction reversed. The female threads (ones on the inside) go onto your raw water bag and the male threads (on the outside) go to your filtered water bottle using the blue coupler. On my squeeze mini the direction of flow is marked but on my new micro squeeze it is not, so it is hard to tell which is correct direction. Check out the Sawyer video here:

    • Karl Halvorson : Mar 13th

      Mike Rachelson, you are absolutely correct. The Sawyer Micro Squeeze that I am using is replacing my regular Sawyer Squeeze that has the flow arrow printed on it. I haven’t actually used my filters for a while and was not paying attention when i took the photos. Luckily, I did not drink any of the water that I thought I was filtering. Thank you for pointing out my error and I hope people read this and/or don’t take my photos as actual directions on how to attach the water containers.

      • mike rachelson : Mar 13th

        Per Karl’s note, the photos are now correct and my comment above no longer applies. I ended up painting a flow direction arrow on my micro squeeze to avoid having a problem myself. Thanks Karl for you article and hope to see more posts from your trip.

    • Karl Halvorson : Mar 13th

      Mike, Thanks again for pointing out my error. I thought it was important enough to change the photos, they should be correct now.

  • Ellen Blair : Apr 6th

    My step son started his journey today – 28 yrs old Ian!!.. If you run into him say hello

    • Karl Halvorson : Apr 6th

      I’ll do that, Ellen!


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