Build an Overland Portable Reverse Osmosis Water System

When getting ready for an overland adventure, you have to make sure you are prepared for the worst-case scenario. What does that exactly mean? You bring tools, spare tires, a generator, winch, rope, shelter, and most importantly, food and water. Even if you run out of the food you brought, you can still find meat sources by hunting down rabbits, birds and etc. But once you’re out of water, then that’s when it becomes dangerous. 

If you’re camping out in an area that has flowing water, then you can survive...hopefully. The problem with “raw” water is that it’s not treated at all. Your tap water back at home has gone through a rigorous process to sanitize it, making sure it kills any live bacteria and viruses and makes it safe enough to drink. 

That beautiful creek that you’re thinking of taking a sip of water from might be pretty, but it could harbor some really nasty organisms that could make you sick. Think about it, that water has come in contact with a variety of organic compounds such as plants, dirt, animals, urine, feces. Contaminants can range from, but not limited to disease-causing parasites such as Cryptosporidium, Giardia, and viruses. 

One of the best ways to make that water safe to drink is to boil it. This helps to kill bacteria and viruses. As effective as that method is, that pot of water will most likely contain dirt, silt, sediment, plant life, or other things that you probably don’t want to drink even if it’s safe to do so. 

An alternative to boiling water to get rid of waterborne contaminants would be to use a reverse osmosis system (RO). But how are you going to do that in the middle of the wilderness? For the most part, people associate RO systems with the filter that’s under the sink in their kitchen. In order to purify water from a stream, you’ll need a way to take that water and feed it through the RO system. 

To do this, you’ll need a transfer pump that goes between the water source and the RO unit. A transfer pump will create enough pressure to push the water through the different filtering stages and through the RO membrane, which in turn produces purified water. 12v transfer pumps are readily available from Amazon or Harbor Freight. Most units will come with at least one garden hose and some sort of pickup filter to prevent any large debris from damaging the pump impellors.

The next thing you’ll need would be a garden hose adapter to convert 3/4" garden faucet/hose to 1/4" poly tubing, which you’ll also need at least 2 feet. For the example below, the transfer pump was mounted on a repurposed ammo can. A 12v motorcycle battery was installed along with a power switch and a charging port for the battery. This keeps everything self-contained and portable.

The next step is to get an iFilters 3-Stage Aquarium Reverse Osmosis System 100 GPD. Don’t let the word “aquarium” fool you, this is just like the other RO units we sell. The only difference is, it doesn’t come with a holding tank. This system doesn’t require electricity to work, which makes it perfect for overland scenarios. 

Now that you have both pieces of equipment, you’ll need to harvest some water. If you have a bucket, or some sort of container that can hold water, fill it up with the water from the stream. Place the intake hose from the transfer pump into your bucket, then connect the brass reducer and poly hose between the pump and RO system. Turn on the transfer pump, make sure the product water line has a container at the end of it to catch all the purified water.  Keep in mind, for every 1 gallon of purified water the system makes, it will discard 3 gallons of wastewater. The wastewater shouldn’t be consumed since the contents of it would be everything the membrane rejected. 

Having this combination of a transfer pump and an RO system can easily become part of any overlander’s tools for survival. They’re both small enough that they could be easily stored in a small bag or tote and if needed, they can be ready to purify water within a few minutes.