Water storage is a foundational element of emergency preparedness, ensuring access to clean drinking water when the municipal supply is compromised or unavailable. Plastic jugs are a common and practical vessel for this purpose, offering durability and portability. The longevity of this stored water depends on much more than simply capping a container and setting it aside. Understanding the appropriate storage duration, selecting the correct food-grade plastic, and maintaining water purity ensures the supply remains safe and palatable over time.
The Standard Shelf Life of Stored Water
The water itself does not inherently “go bad,” but its quality, taste, and safety can decline due to storage conditions and container material. Most public health agencies recommend rotating home-filled water in plastic jugs every six to twelve months. This recommendation ensures the water remains fresh and palatable for drinking during an emergency. Commercially bottled water, sealed under sterile conditions, often has a much longer shelf life, sometimes up to five years, though this date typically relates to the quality of the plastic packaging rather than the water itself. When storing chlorinated tap water, the primary concern is the slow dissipation of the disinfectant and the potential for off-tastes.
Selecting and Preparing Plastic Containers for Long-Term Storage
Choosing the Right Plastic
The single most important factor for long-term storage is choosing a container made from food-grade plastic that will not leach harmful chemicals into the water. Look specifically for containers marked with the recycling codes #2 (HDPE – High-Density Polyethylene) or #1 (PET or PETE – Polyethylene Terephthalate), as these are approved for food and beverage contact. HDPE is known for its durability and impact resistance, while PET is commonly used for clear, single-serving water bottles.
Containers to Avoid
Containers that previously held non-food items, such as milk or juice, should be avoided for long-term storage. Their porous nature makes them difficult to clean of residual proteins and sugars, which can encourage microbial growth. Never use containers that have held toxic substances like bleach, pesticides, or petroleum products, as these chemicals can transfer into the water, making it unsafe to drink.
Cleaning and Sanitizing
Before filling any container, it must be thoroughly cleaned and sanitized to eliminate existing bacteria or manufacturing residue. Wash the container with dish soap and water, followed by a complete rinse with clean water. Sanitize using a solution of unscented household chlorine bleach (typically 1/3 cup per three gallons of water). This solution should coat all interior surfaces, be left for at least thirty seconds, and then poured out, allowing the container to air-dry before filling with potable water.
Maintaining Water Quality During Storage
Storage Environment
Once the jugs are filled with clean water, the storage environment plays a significant role in preserving the water’s quality until the rotation date. Stored water should be kept in a cool, dark location, as exposure to heat and light can encourage the growth of algae and accelerate the breakdown of the plastic. It is also important to store the containers away from sources of gasoline, solvents, or other chemicals. Plastic is slightly permeable and can absorb chemical vapors, which can taint the water’s taste.
Disinfecting for Long-Term Storage
For water intended for indefinite storage, or if the source water is not from a reliable public supply, a small amount of unscented, regular household bleach can be added as a disinfectant. This process helps prevent microbial growth throughout the storage period. A common guideline for clear water is to add four to eight drops of bleach (5.25% to 8.25% sodium hypochlorite) per gallon of water.
The water and bleach should be thoroughly mixed and then allowed to stand for at least thirty minutes before consumption. After this waiting period, a faint chlorine odor should be detectable, which indicates that the disinfection process was successful. If no odor is present, the dosage should be repeated. This chlorine additive maintains a residual disinfectant that helps protect the water until it is needed.