How a Flood Affects Your Water
The primary risk to water from a flood is contamination. Bacterial contamination is a major concern during and after a flood. A municipal water system monitors water quality for its customers and can alert them if the water is unsafe but, conditions may make notification difficult and if you rely on a private water source, it’s up to you to monitor your water supply to ensure it’s safe to use.
Hurricanes create flooding and can also cause physical damage to wells and water treatment facilities. They disrupt communications as well. These storms are a concern for those on municipal water as well as those who rely on wells for water.
Is Your Water Safe After a Flood?
If there’s been a flood in your area, it’s best to assume the water is contaminated. Don’t ingest it or allow it to touch your skin until you confirm it’s safe. Use an alternate source of water for purposes such as:
- Drinking
- Cooking
- Making tea or coffee
- Mixing baby formula, juice, etc.
- Pet care
- Washing dishes, doing laundry, handling general cleaning, etc.
- Bathing, washing hands, brushing teeth, etc.
Alternate Sources of Water After a Flood
There are two common alternatives if your water is contaminated:
- Bottled water
- Boiled water
According to the Environmental Protection Agency (EPA), referencing the World Health Organization (WHO), pouring water through a clean cloth or coffee filter and then bringing the filtered water to a rolling boil for at least a minute — or at least three minutes at high altitudes — kills pathogenic protozoa, viruses and bacteria. Let the boiled water cool and keep it in a clean, covered storage container.
Follow Public Safety Instructions
If you’ve experienced a flood in your area, pay attention to information from local officials about the safety of water in the area. Follow instructions about boiling water or using bottled water. However, if official information isn’t available for any reason, a water test is helpful.
Lab Water Tests After a Flood
Have your water tested by an EPA-certified lab if possible. This is the best, most accurate option. Sending a sample by mail might not be practical, but your local health department should be able to help you locate a nearby lab in the event of a flood.
Home Water Tests After a Flood
If getting a sample tested at a lab isn’t possible, a home test kit for coliform bacteria can be helpful. The presence of coliform bacteria indicates that harmful bacteria might be present in your water. Bacteria tests are simple and can give you results within 24 to 72 hours.
While bacterial contamination is the most common concern for well water after a flood, flood waters may bring other contaminants, such as fuel or pesticides, into your well water supply. If your water has a smell of fuel or chemicals don’t use it or attempt to boil or purify it. Contact your health department.
How to Test for Bacteria With a Household Water Testing Kit
While having your water tested by a certified lab is the best way to check for the presence of bacteria in your water, a home test kit for bacteria is a relatively quick way to pre-screen your water. Some test kits also provide a means for lab testing with an additional charge. We’ve got general steps for testing water after a flood, but always follow the instructions that come with your test kit.
Using a Residential Water Test Kit
After Testing Your Water for Bacteria
If your water tested positive for bacteria or you’re unsure of the safety of your water, don’t use it for any purpose that allows you to ingest it or allows it to contact your skin — drinking, mixing baby formula, cooking, dishwashing, laundry, etc. Rely on a safe alternative source of water, such as bottled water or properly boiled water. See the information in Alternative Sources of Water above.
Contact a licensed well driller if you determine your well is contaminated or damaged. Continue using an alternate safe water source until you've confirmed your water is free of bacteria.