Emergencies and disasters can strike when we least expect them, leaving us without clean drinking water. Access to safe water is essential for making it through these situations, and it’s important to be prepared with emergency drinking water, before it’s too late.
Calculating Personal Needs
When it comes to emergency preparedness, a common guideline is to have at least one gallon of emergency drinking water per person per day. This should cover drinking, cooking, and basic hygiene needs. However, this is a baseline estimate and actual requirements can vary depending on factors such as age, physical activity, climate, and health conditions.
Children, pregnant women, nursing mothers, and individuals in hot climates may require more water. Not to mention you’ll need to account for any pets or livestock as well. It’s also important to consider how long an emergency might last, or how long you could be stranded without drinking water.
The Federal Emergency Management Agency (FEMA) recommends having at least a three-day supply of emergency drinking water for each person, but in more severe scenarios, such as natural disasters that disrupt water supply lines for an extended period, at least a 2-week supply is recommended, which comes out to at least 14 gallons per person, per household.
Special considerations:
- Hot Climates: If you live in an area with high temperatures, you may need to store more water due to increased hydration needs.
- Pregnant Women & Sick Individuals: They may require more fluids to stay healthy.
For pets, ensure they have access to clean water and include their needs in your emergency plan. Livestock, on the other hand, may require larger quantities of water, so understanding their specific needs and having a plan for their care is crucial.
Safe Emergency Drinking Water Storage
It’s important to store water in containers fit for long-term water storage – otherwise, contamination of your drinking water is likely. Commercial water bottles and containers that have been previously used can transfer toxic substances or microplastics into your water.
Use food-grade containers specifically designed for water storage, like the high density polyethylene (HDPE) water storage tanks from Tank Depot or camping supply stores. These are specifically rated to store food and water in a safe manner, and won’t contaminate their stores over time. Avoid using containers that have previously held chemicals or non-food substances, as they can leach harmful substances into the water.
If you’re in an emergency and you don’t have a food-grade storage container available, the Center for Disease Control and Prevention (CDC) recommends that you choose a container that:
- Has a top that can be closed tightly.
- Has a narrow neck or opening so water can be poured out easily.
- FDA-approved, food-grade water storage containers (e.g., high-density polyethylene (HDPE) water tanks).
- Use durable, unbreakable, BPA-free plastic containers, ceramic or stainless steel tanks.
- Large-capacity water storage solutions, such as rainwater harvesting tanks.
How to Purify Drinking Water in an Emergency
In an emergency, you may need to treat water from lakes, rivers, or other questionable sources. Follow these CDC-recommended methods to ensure it’s safe to drink:
Boiling (Most Effective)
- Bring water to a rolling boil for at least 1 minute (or 3 minutes at elevations above 6,500 feet).
- Let it cool before drinking.
- To improve the taste, pour the boiled water between two containers or add a pinch of salt per quart.
Disinfection with Bleach
If boiling is not an option, you can use household bleach (5-9% sodium hypochlorite) to disinfect water:
- 1 quart/liter: Add 2 drops of bleach
- 1 gallon: Add 8 drops of bleach
- 5 gallons: Add 40 drops of bleach
- Stir well and let the water sit for at least 30 minutes before drinking.
- If the water is cloudy, first filter it through a clean cloth, paper towel, or coffee filter.
Chemical Water Treatment (Tablets or Drops)
- Use chlorine dioxide, iodine, or purification tablets (follow manufacturer instructions).
- Note: Iodine is NOT safe for long-term use—pregnant women and people with thyroid conditions should avoid it.
Water Filtration
- Portable water filters can remove bacteria and parasites like Giardia and Cryptosporidium, but they do NOT remove viruses.
- Use a filter with an absolute pore size of 1 micron or smaller, and then disinfect the water afterward.
Solar Disinfection (SODIS)
- Fill clean, clear plastic bottles with clear water.
- Lay bottles in direct sunlight for at least 6 hours (or 2 days if cloudy).
- This method reduces bacterial contamination but is not 100% reliable for heavily contaminated water.
What NOT to Do
- Do NOT use contaminated water from radiators, boilers, or floodwater.
- Do NOT rely on filtering alone—always pair it with a disinfecting method.
Step by Step Guide to Cleaning and Sanitizing Your Water Storage Containers
Before filling with water, the CDC also recommends these steps to clean and sanitize water storage containers:
- Wash the storage container with soap and rinse completely with water.
- Sanitize the container with a solution made by mixing 1 teaspoon of unscented liquid household chlorine bleach in 1 quart (4 cups) of water. Use bleach that contains 5%–9% sodium hypochlorite.
- Cover the container tightly and shake or stir it well. Make sure the sanitizing bleach solution touches all inside surfaces of the container. For larger tanks, you’ll need to either spray a coating of the solution along the inside of the tank walls, or use a tool to achieve this.
- Wait at least 30 seconds and then drain the sanitizing solution out of the container.
- Let the empty container air-dry before use.
- Fill the sanitized container with clean water and cover it with a tight lid. Something like threaded manway assemblies that can screw tight onto vertical water tanks will work well for this purpose. If you don’t have access to this type of lid, seal as well as possible to avoid letting outside contaminants into the container.
What About Bottled Water?
For short-term emergencies, commercially bottled water is good to have on-hand, but should not be relied upon in a crisis scenario. Bottled water supplies tend to be extremely limited when disasters strike. To truly be prepared in such situations, storing tap water in clean containers, rotating them every six months, and treating the water properly to disinfect it will be necessary.
In addition to storing water beforehand, knowing how to source water from your surroundings can save you in an emergency situation. Rivers, lakes, and rainwater can be great sources of clean drinking water, though it is important to treat the water that comes from these sources. A solution like rain harvesting tanks will ensure that you always have fresh drinking water available, year-round, and especially in a time of crisis.
Further guidance on how to treat and store emergency drinking water will follow in the 2nd part of our emergency preparedness blog series.
