Understanding Non-Potable Water
Non-potable water is water that is not safe for drinking, personal, or culinary use. This may be because its origin is known to be contaminated or simply because the water has not been tested or treated and therefore is considered unsafe.
Waterborne Illnesses
When preparing water for storage, telling the difference between the water you can and cannot use is imperative. While our water storage contains drinkable water, non-potable water has its uses.
When you don’t know the safety of any given water source, it’s best to err on the side of caution and either not drink it or treat it first. Drinking contaminated water can lead to extreme illness or death. In 2017, the Centers for Disease Control and Prevention (CDC) reported almost half a million hospital admissions and 7,000 deaths in the United States due to waterborne diseases.
Water Storage
There are sources of non-potable water found both in nature and at home. These sources can be used, after treatment, for human consumption or to be used untreated for non-consumption needs. Always assume the following water sources are contaminated and need to be treated.
Natural Sources
Lakes, Streams, Rivers
If you're fortunate to have one of these bodies of water near your home, you can feel confident in using it as part of your non-potable plan. Water from these sources can be used for drinking if treated or can be used for non-potable purposes like watering the garden or flushing the toilet.
Rainwater
Rainwater is one of the safest external sources of water and can be collected using barrels or other containers. Although typically cleaner than many other sources, rainwater should still be filtered and treated before drinking to ensure safety. Learn more about creating a rain harvesting system.
Solar Still
You can create a solar still by digging a hole, placing a container in the center, covering the hole with plastic, and putting a small rock in the center to weigh it down. As the sun heats the area, moisture from the ground and plants will evaporate, collect on the plastic, and drip into the container. Always filter the water before drinking to remove any potential contaminants.
Ground Water
Groundwater is the water present beneath the earth’s surface in rock and soil pre-spaces and in the fractures of rock formations. Nearly 98% of the world’s freshwater is underground. Groundwater can provide safe drinking water if the source is properly treated.
Snow & Ice
In cold climates, snow and ice are valuable water sources. While consuming small amounts is okay, as a rule it’s important to melt them first, as consuming snow directly can lower your body temperature and cause dehydration. Once melted, treat the water as you would any other external source.
Home Sources
Water Heater
Many hot water heaters hold 75+ gallons of water. Water can be drained from the bottom of the tank through a built-in spigot using a garden hose and a bucket. Before draining, turn on a hot water faucet in your home to allow air into the system.
Toilet Tank
The amount of water that a typical toilet tank holds varies depending on the model. Most standard tanks typically hold between 1.5 to 7 gallons of water. It’s not a lot, but every little bit helps. Do not confuse this water supply with toilet bowl water, which should not be used.
Melting Ice
Use your ice trays as a strategic part of your emergency water plan because every bit helps. Be proactive and make sure that your tray is always full or that your automatic ice maker works. If your freezer has room, freeze more ice than you may otherwise.
Is Treated Pool Water Safe to Drink?
Swimming pool water might look like an easy backup in an emergency, but it comes with some serious risks. Pool water is loaded with chemicals—chlorine, algaecides, and other additives—that help keep it clean for swimming but aren’t meant for drinking. Even if you filter it, those chemicals can stick around and be harmful if consumed. Plus, pools are open to the elements, meaning bacteria, dirt, and even critters can end up in the water.
If there's absolutely no other water available, pool water might be treated for drinking—but only after multiple purification steps like filtering, dechlorinating, and disinfecting (boiling or chemical treatment). Even then, it's risky, and it's definitely not ideal. The safest move? Have a proper emergency water supply ready so you don’t have to gamble on pool water. If you do need it, stick to non-drinking uses like cleaning or sanitation.
Water Storage
Uses of Non-Potable Water
There are a few instances when non-potable water is just fine to use. Always label a water container accordingly so it does not get confused with your drinking and cooking water.
- Garden watering
- Toilet flushing
- Laundry
- Cleaning non-foods contact surfaces such as floors.
- Washing and rinsing both ceramic dishes and metal utensils. Make sure they are thoroughly dry before reusing.
When Not to Use Non-Potable Water
There are instances when you should never use non-potable water, in its pre-treated state, because of the potential to get sick.
- Personal hygiene - brushing teeth, bathing, showering, and handwashing.
- Food preparation - washing, cooking, baking, preparing food in any fashion.
- Surfaces that encounter food - including containers made of plastic, wood, and clay as bacteria can persist on porous materials.
Learn how to purify non-potable water, if necessary, to make these tasks safe.
Finding Local Water Resources
Do you have a natural lake or stream in your area? This can greatly reduce the amount of water you need to store. Check out this interactive map and see if it can help you find natural water resources near you. If so, you can make this part of your non-potable water plan.