Can You Store Purified Water for Long-Term Use?

According to the Centers for Disease Control and Prevention, storing safe drinking water is a critical component of emergency preparedness. This leads many to wonder, can you store purified water effectively for long-term use? The answer is yes, but proper methods are crucial to ensure its quality and safety over time.

Quick Summary

This guide details the best practices for storing purified water, covering proper container selection, sanitation, and ideal storage conditions. It also contrasts short-term versus long-term storage methods, addressing potential contaminants and maintenance routines to preserve water quality.

Key Points

• Container Choice: Use food-grade plastic (HDPE #2), glass, or stainless steel to prevent chemical leaching and contamination.

• Proper Sanitation: Clean and sanitize all containers thoroughly with soap and a diluted bleach solution before filling for long-term storage.

• Ideal Storage Conditions: Store purified water in a cool, dark, and dry location, away from direct sunlight and chemicals, to preserve its quality.

• Regular Rotation: For optimal freshness and taste, rotate your stored water every 6 to 12 months, using the oldest water first.

• Labeling is Crucial: Clearly label each container with "Drinking Water" and the date of storage to track its age and rotation.

• Refrigerate After Opening: Once a container of purified water is opened, it is best to refrigerate it and consume it within 24-48 hours to minimize bacterial growth.

• Aerating Stored Water: If stored water tastes flat, simply pour it back and forth between two containers to reintroduce oxygen.

The Essentials of Storing Purified Water

When it comes to preparing for an emergency or simply having a backup supply, many people turn to purified water. While the purification process removes most contaminants, proper storage is what ultimately dictates how long the water remains safe and fresh. Improper storage can lead to recontamination, algae growth, and unpleasant tastes or odors.

Choosing the Right Storage Containers

The container you use is one of the most important factors for successful water storage. Not all containers are created equal, and some can degrade or leach chemicals into the water over time, especially when exposed to heat or sunlight.

• Food-Grade Plastic: Look for containers labeled with the HDPE (High-Density Polyethylene) code, typically indicated by the number "2" inside the recycling symbol. These are robust and less permeable than single-use plastics like PET (code "1"), making them suitable for longer storage periods. Avoid using old milk jugs, which are difficult to sanitize completely.
• Glass: Glass is non-porous and won't leach chemicals or odors into the water, making it an excellent long-term option. The main drawback is that it is heavy and susceptible to breakage.
• Stainless Steel: High-quality, non-corrosive stainless steel is another great option for long-term storage. Like glass, it won't affect the water's taste or quality. However, it should not be used with chlorine-treated water, as chlorine is corrosive to most metals.

Short-Term vs. Long-Term Storage

The duration of your storage plan influences the specific techniques you should employ. Short-term storage (days to weeks) has less stringent requirements than long-term storage (months to years).

Preparing for Long-Term Storage

For a backup supply lasting several months or years, follow these best practices:

1. Sanitize Containers Thoroughly: Before filling, wash containers with hot, soapy water, rinse completely, then sanitize with a diluted bleach solution (1 teaspoon of unscented household bleach per quart of water). After 30 seconds, pour out the solution and rinse with clean water.
2. Fill Completely: Fill the sanitized containers to the brim with your purified water, leaving as little airspace as possible to prevent algae growth.
3. Label and Date: Use a permanent marker to label each container with "Drinking Water" and the date of storage. This helps with proper rotation.
4. Add a Water Preserver (Optional): For very long-term storage (up to 5 years), some people add a water preserver or Biofilm Drops, though for already purified water stored properly, this is not always necessary for safety.
5. Create a Rotation System: For best taste, refresh your water supply every 6 to 12 months. Use the "first-in, first-out" method, using older water for drinking and refilling containers with a fresh batch.

Maintaining Water Quality During Storage

Once stored, the environment plays a crucial role in maintaining water quality. Here are key points to consider:

• Location: Store your containers in a cool, dark, and dry place. High temperatures and direct sunlight can degrade plastic and promote bacterial and algal growth.
• Separation: Store water away from potential contaminants like gasoline, pesticides, and other chemicals. Plastic containers can be permeable to these vapors, which can affect the water's taste and safety.
• Taste: Over time, water can develop a "flat" or "stale" taste from a lack of dissolved gases. You can easily aerate the water by pouring it back and forth between two clean containers a few times to restore the taste.

Comparison of Water Storage Options

Feature	Glass Containers	Food-Grade Plastic (HDPE)	Stainless Steel Containers
Leaching	No leaching of chemicals or flavors.	Minimal leaching, especially with HDPE; PET bottles more prone.	No leaching or rust with high quality materials.
Durability	Fragile; can break easily if dropped.	Durable and flexible; less prone to breakage.	Very durable and resilient.
Cost	Can be more expensive initially.	Inexpensive and widely available.	Moderately expensive.
Permeability	Impermeable to odors and vapors.	Slightly permeable; can absorb nearby odors.	Impermeable to odors and vapors.
Weight	Heavy, especially in large volumes.	Lightweight and portable.	Can be heavy, though lighter than glass.

Conclusion: Ensuring a Safe and Ready Supply

Yes, you can absolutely store purified water. The key to maintaining its safety and quality is diligence in preparation and storage. By selecting the correct food-grade containers, ensuring they are properly sanitized, and storing them in a cool, dark place away from chemicals, you can build a reliable emergency water supply. Rotating your stock annually ensures freshness and peace of mind, so you are always ready for any situation. Following these steps ensures your purified water will be a safe and refreshing resource when you need it most. For more information on general emergency preparedness, a great resource is the CDC's guidelines on safe water storage.

Frequently Asked Questions

Does purified water need to be stored differently than regular tap water?

Yes, while the storage methods are similar, purified water lacks the chlorine that initially helps inhibit bacterial growth in tap water. Therefore, storing it in clean, sealed containers in a cool, dark place is even more critical to prevent recontamination.

How long can purified water be stored before it goes bad?

If stored correctly in a sanitized, food-grade container in a cool, dark place, purified water can last for years. However, for best taste, it should be rotated every 6 to 12 months. The "best by" date on commercially bottled water refers to the plastic bottle itself, not the water.

What kind of plastic containers are safe for storing purified water?

Food-grade plastic containers are safe, specifically those marked with the HDPE (High-Density Polyethylene) code "2". Avoid using single-use plastic bottles for long-term storage, as they are more permeable and can leach chemicals over time.

Can I store purified water in the freezer?

Yes, you can store purified water in the freezer in food-grade plastic containers. Leave some headspace in the container to allow for expansion as the water freezes. Frozen water can also help keep food cold during a power outage.

Why does my stored water sometimes taste flat?

The flat taste is due to a lack of dissolved oxygen and other gases that give water its freshness. To fix this, simply pour the water between two clean containers a few times to aerate it.

How do I sanitize old containers for water storage?

To sanitize, first wash the container with hot, soapy water and rinse well. Then, rinse with a solution of 1 teaspoon of unscented household bleach per quart of water. Let it sit for 30 seconds before rinsing again with clean water.

What is the best way to keep my long-term water supply fresh?

The best practice is to establish a rotation system. Label all containers with the storage date and replace the oldest water every 6-12 months. This ensures you always have a fresh supply on hand.