A reader posed a question: how long is it safe to keep emergency water before replacing it?
Water is the single most important emergency supply item. We can survive for weeks without food, but only four days without water.
The recommended amount of water to store is 1 gallon (4 litres) per person per day. For a family of 4 to be prepared for 72 hours, that would be 12 gallons (48 litres) of water to store… and to replace.
The emergency water in our garages or closets has to be replaced periodically, but how often?
Water bottles purchased in stores have expiry dates, because expiry dates are required by law for all packaged foods and beverages. However, an expiry date isn’t a useful guideline in the case of water. Water kept for more than a few months will begin to taste flat, but taste alone won’t tell you if it’s still safe to drink.
The main safety issue with water storage is that bacteria, fungi and algae start to grow in water eventually. Algae grows more quickly in warmth and light. Water can remain safe twice as long if it’s kept in cold, dark place like an unheated basement or garage.
To figure out how often to replace your emergency water, there are a number of factors to consider:
–the water source, from a well or tap, distilled or non-sterile ”glacier” water
–the storage container used (camping container, sterile sealed bottle, etc).
–exposure to light
–the temperature at which it’s stored
Water stored in plastic will begin to take on a plastic taste over time, but not to unsafe levels if the plastic is food grade. Glass or large plastic containers are more environmentally friendly choices, since there’s a lot of waste involved in plastic bottles.
If you catch rainwater in recycled industrial barrels, you may want to get their food grade status checked. If you store water outside, allow room in the container for the water to expand when frozen.
The most important thing to remember:
if the SHTF and all you have to drink is water that’s been in storage for years, a few drops of bleach could make it safe to drink.
Ditto for water you can access in your hot water tank or toilet tanks. Not appetizing, but using that water could save your life.
Be aware that bleach has a shelf life of about nine months. I’ve added a bottle of bleach to my growing supplies checklist. It’s a good idea to add a new bottle of bleach to your supplies at least once a year. Tie an eyedropper to the bleach container. You’ll need to use 8 drops per gallon/4 litres, 16 drops if the water’s cloudy.
Water tastes flat when stored awhile because all the air gradually goes out of it. Shaking up the water before drinking can re-aerate it, which improves the taste a bit.
So to sum up, I’d suggest the following rules of thumb for replacing emergency water:
On one extreme: if you put your own well water into camping containers and store it in a warm and bright space, you probably should replace it every few months. Don’t forget to rinse out your containers with a bleach solution to kill anything that may have taken up residence in the meanwhile.
On the other extreme: if you buy sealed, glass containers of distilled water from a grocery store and keep it in a dark, cool basement, you can probably get away with replacing it every three years.
Most of us may have a situation somewhere in the middle of these extremes, but hopefully this gives you a good idea of the factors to keep in mind.
Some people suggest picking a recurring date to update all your perishable supplies. Jim Serre, who commented on my last Prep Step, suggested rotating out perishables (including flashlight batteries) every six months, when the clocks are changed.
I think I’ll start with at least once a year, and plan to do it annually on the Great ShakeOut Day in October.
- The Survival Mom website has a great article on how to store and use bleach to purify emergency water. The article includes tips on how to use it, and a discussion on buying calcium hypochlorite from a pool supply store to make your own bleach, since the calcium hypochlorite has an indefinite shelf life and it’s cheap like borscht.
- 4 Things to Hoard for an Emergency (allstate.com)
- Self-filling water bottle takes cues from desert beetle (phys.org)
- Tips for clean drinking water when Hurricane Sandy strikes (cbsnews.com)