Boiling water for 1 minute is always the best way to disinfect (to kill germs in) your water during a boil water advisory. But if you can’t boil water (for example, the power is out during a very bad storm), you can do one of the following:
Chlorine and iodine work well to kill bacteria and viruses. However, these disinfectants will not kill parasites like
Cryptosporidium. It can be hard to know if there’s a risk of parasites, especially in an emergency. If you can’t boil water, the best way to make water safe is by doing more than 1 type of treatment.
You have to treat for parasites
before you disinfect with chlorine or iodine. Before you use chlorine or iodine to disinfect water, use one of these treatments to remove parasites:
You can use water purification tablets or bleach to chlorinate your water.
Water purification tablets
You can buy the tablets from most outdoor supply or camping stores. Follow the directions on the package.
To chlorinate your water using bleach, you will need:
If your water is
If your water is
Don’t use iodine for more than
3 weeks each summer (in controlled doses) because there is a risk of thyroid problems and iodine sensitivity.
Don’t drink water disinfected with iodine if you:
To disinfect water with iodine, you need liquid iodine (2%) or iodine tablets. If you use tablets, follow the directions on the package. If you use liquid iodine, follow the directions listed below. You can buy iodine at most drugstores and some outdoor supply or camping stores.
Liquid iodine works best when you add it to warm water at a temperature of 20˚C (68˚F).
If you have any questions about your water, contact Alberta Health Services Environmental Public Health.
Current as of: February 18, 2021
Author: Environmental Public Health, Alberta Health Services
This material is not a substitute for the advice of a qualified health professional. This material is intended for general information only and is provided on an "as is", "where is" basis. Although reasonable efforts were made to confirm the accuracy of the information, Alberta Health Services does not make any representation or warranty, express, implied or statutory, as to the accuracy, reliability, completeness, applicability or fitness for a particular purpose of such information. Alberta Health Services expressly disclaims all liability for the use of these materials, and for any claims, actions, demands or suits arising from such use.