Hi Stephanie,
Typically, if the water was stored in a high quality potable water container for the last year (sealed) I would be willing to bet the water is fine as is. One year isn’t that long for water if it has been kept sealed in an appropriate container. This is especially true if it was treated prior to storage.

The problem comes if the container is either not made specifically for storage of drinking water or if it has been damaged in any way. If it has been kept in an area out of direct sunlight and has been sealed for the last year, which I am assuming it has being that it is kept in your garage, then the water is probably fine. However, if you still have a question about it, you have a few options:

1 – Get the water tested by an EPA-certified laboratory. You can call your local water authority or check https://www.epa.gov/dwlabcert/contact-information-certification-programs-and-certified-laboratories-drinking-water for a list of labs in your area.

2 – Drain and refill the water. Make sure you treat it or at least test it’s chlorine levels as detailed in this article afterwards filling it back up.

3 – Re-test the chlorine levels of the water currently in the tank and re-treat as necessary.

If you want my opinion, I think the best option (by far) would be option number 2. I don’t know how expensive the water is where you live but I did calculations using my own water bill and found that it only costs between $5 – $7 for me to fill up my two 275 gallon emergency water totes (550 gallons total).

That will be far cheaper than testing the water that is in the tanks now, I assure you. Then once they are refilled, check the chlorine levels, treat if necessary, and seal it up! If you want, you can do this once a year to be safe. It’s also a good idea to have a few emergency water filters on hand as a backup!

Gregg

I haven’t heard of that before as a means to store water. There also isn’t much information about this online from what I could find. There is some research that microbial growth is prevented by high pressures, but I think the pressures have to be pretty high to make any difference.

I did find one study by the Center for Studies in Physics and Biology at Rockefeller University, New York which discusses how E. Coli reacts to high pressure environments.

You can read the study here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3736669/

The study states that E. Coli can survive in pressures up to 400 atm (or over 5,800 psi). That is a lot of pressure!

I think in most cases, it would be easier to treat the water with bleach, seal the container, and store it away. If you have any information about this method for storing water, please post it. I would love to read it!