How long can well water be stored safely?

December 21, 2025 •

3 min read

According to the Centers for Disease Control and Prevention (CDC), replacing your stored water every six months is a key step to maintaining quality and safety. The question of how long can well water be stored depends heavily on initial water quality, proper treatment, and storage conditions.

Quick Summary

Storing well water for emergencies or daily use requires specific preparation and proper handling to ensure it remains safe to drink. The duration for which it can be stored depends on the initial treatment and the type of container used. Key steps include using food-grade containers, storing in a cool, dark place, and establishing a regular rotation schedule.

Key Points

Pre-treat Well Water: Disinfect well water before storage with unscented bleach (8 drops per gallon) or by boiling to kill potential pathogens.
Use Food-Grade Containers: Only store water in food-grade plastic, stainless steel, or glass containers to prevent chemical leaching and contamination.
Store in Ideal Conditions: Keep containers in a cool, dark, and dry location, away from direct sunlight, chemicals, and strong odors.
Follow a Rotation Schedule: Replace home-stored well water at least every six to twelve months to ensure quality and freshness.
Clean and Sanitize Containers: Before each use, thoroughly wash and sanitize your storage containers with a weak bleach solution to prevent bacterial growth.

Essential Factors for Safe Well Water Storage

Storing well water safely for an emergency is not as simple as filling up a container and putting it away. The key is controlling the factors that cause water quality to degrade over time. Unlike city water, which contains a residual disinfectant, well water is untreated and may contain bacteria or other microorganisms from the outset.

Disinfecting Well Water for Storage

One of the most critical steps for long-term well water storage is disinfection. Boiling is the most effective method for killing pathogens, requiring a vigorous boil for several minutes. An alternative for clear, non-turbid water is chemical treatment using unscented household bleach containing 5% to 9% sodium hypochlorite. For a gallon of water, add 8 drops (1/8 teaspoon) of bleach. For 55 gallons, use about two tablespoons and one teaspoon. Always follow the manufacturer's instructions and ensure the bleach is fresh, as potency diminishes over time. After adding the bleach, cap the container, mix well, and let it stand for at least 30 minutes before storing. A slight chlorine smell should be noticeable, indicating the treatment is effective.

Selecting the Right Storage Containers

Using the right containers is vital for maintaining water safety and quality. Containers must be food-grade to prevent harmful chemicals from leaching into the water.

Food-Grade Plastic Containers: Large, heavy-duty barrels, jugs, and carboys made from high-density polyethylene (HDPE) or PET plastic are excellent choices. Ensure they are labeled food-grade and BPA-free. Avoid thinner, single-use plastic bottles for long-term storage, as they can degrade and are more permeable.
Stainless Steel Containers: Stainless steel is durable, non-corrosive, and an excellent long-term option, though it is often more expensive.
Glass Containers: Glass canning jars or jugs are non-permeable and work well, especially for smaller quantities, but their fragility makes them less ideal for bulk emergency storage.

Preparing and Storing Your Containers

Proper preparation is just as important as the storage itself. Before filling, containers should be thoroughly cleaned with soap and water, rinsed, and sanitized with a bleach solution.

Wash containers with hot, soapy water.
Rinse thoroughly to remove all soap residue.
Sanitize by adding a solution of 1 teaspoon unscented household bleach to a quart of water, shaking, and waiting 30 seconds before rinsing and air-drying.
After filling with treated well water, label the container with the date and "Drinking Water".
Store the containers in a cool, dark, and dry place, away from direct sunlight and chemicals like pesticides or gasoline. This prevents algae growth and vapor permeation through plastic.

The Importance of Water Rotation

Even with optimal storage, water quality can degrade. The CDC recommends replacing home-stored water every six months. If the water has a flat taste, aeration can improve it. Simply pour the water back and forth between two clean containers several times. Regular testing of stored water is also essential, especially for longer periods.

Comparison of Well Water Storage Methods


Storage Method	Initial Treatment	Container Type	Estimated Lifespan	Pros	Cons
Chlorinated Cold Storage	Unscented bleach	Food-grade plastic or steel barrels	6–12 months	Cost-effective, simple process, effective against pathogens.	Requires regular rotation, potential for flat taste over time.
Boiled Canning	Rolling boil for 20 mins	Glass canning jars with lids	Indefinite (as long as seal is intact)	Sterilizes water completely, long-term stability, tamper-evident seals.	Time-consuming, glass is fragile, not practical for large quantities.
Frozen Storage	Disinfected with bleach	Food-grade plastic (with headspace)	6–12 months	Keeps water fresh, helps keep food cold during power outage.	Container expansion can cause breakage, limited by freezer space.

Conclusion

For well water to be safely stored, proper treatment and storage are non-negotiable. While bottled water can be an option, treating and storing your own well water can be a more sustainable and cost-effective approach. The key takeaway is to start with pure water, disinfect it correctly (boiling or chlorination), use appropriate food-grade containers, and store them in a cool, dark place. By establishing a routine of rotating your stock every six months, you can ensure a supply of safe, potable water for any emergency. Regularly inspecting and testing your stored water is a small effort for a significant return in peace of mind. For more detailed information on emergency water purification, visit the U.S. Environmental Protection Agency website.

Frequently Asked Questions

While water itself does not 'go bad,' stored well water can become unsafe due to microbial growth if not properly disinfected and stored. Untreated well water is especially susceptible to bacterial contamination.

To prepare well water, you must first disinfect it. The most common methods are boiling (for short-term use) or adding a specific amount of unscented household chlorine bleach to the water before sealing it in a food-grade container.

No, it is not recommended. Milk jugs are difficult to clean completely and can harbor bacteria, while thin plastic soda bottles are permeable and can leach chemicals or absorb odors over time.

The best containers are opaque, food-grade options made from materials like heavy-duty plastic (HDPE), stainless steel, or thick glass. These should be airtight and have a secure, tight-fitting lid.

It is generally recommended to replace your stored well water every six to twelve months. This practice ensures that your emergency supply remains as fresh and safe as possible.

To improve the taste of water stored for a long time, aerate it by pouring it back and forth between two clean containers. If the chlorine smell is too strong, it should dissipate once the container is opened.

Storing water away from direct sunlight prevents plastic containers from degrading and reduces the risk of algae or microbial growth. A cool, dark storage location is essential for maintaining water quality.