Storage first
Ready.gov uses one gallon per person per day for several days as a planning baseline for drinking and sanitation. Hot weather, illness, pregnancy, nursing, children, pets, medical needs, and cleanup can raise that number. Keep a baseline of ready-to-drink water before relying on filters or disinfectants. Larger containers are efficient at home; smaller bottles are easier to distribute, freeze, and carry.
Water storage checklist
- Use food-grade containers with tight caps; keep them away from fuel, pesticides, solvents, and strong odors.
- Label each container with the fill date and store it in a cool, dark place.
- Keep some water portable for evacuation and some in larger home containers for sheltering in place.
- Store extra for pets, baby formula, medication, handwashing, tooth brushing, and minimal dish cleanup.
- Keep a clean bucket, funnel, towels, unscented household bleach where appropriate, and backup treatment instructions.
Treatment order
CDC guidance says to use bottled, boiled, or treated water when tap water may be unsafe, and boiling is the best way to kill germs when it is practical. If water is cloudy, let sediment settle and pre-filter through a clean cloth before treatment. Filters can remove many particles and organisms, but they vary by design and may not address chemicals, saltwater, or every pathogen. Disinfectants require correct dose, contact time, and water clarity.
Backup sources
Potential home sources include sealed stored water, melted ice, water heater tanks, and toilet tanks that do not contain chemical cleaners. Rain capture, streams, ponds, and flood-adjacent water require a safety decision and treatment plan. Never use water from home heating radiators or boilers for drinking, cooking, or hygiene.
Container selection and storage conditions
Use food-grade plastic containers labeled PETE or PET (recycling code 1) or HDPE (recycling code 2) for long-term storage. Avoid containers that previously held non-food liquids. Two-liter soda bottles, commercial water jugs, and purpose-built food-grade containers all work. Keep stored water away from direct sunlight, gasoline, paint, and cleaning solvents, as polyethylene can absorb vapors. Tap water stored in a clean, sealed container lasts about six months before quality begins to degrade; commercially bottled water is safe until the manufacturer's printed date.
Treatment methods compared
Boiling is the most reliable method and kills bacteria, viruses, and most parasites — bring water to a rolling boil for one minute (three minutes above 6,500 feet elevation). Chemical disinfection with unscented household bleach (6–8.25% sodium hypochlorite) uses 8 drops per gallon of clear water or 16 drops per gallon of cloudy water; stir and let stand 30 minutes before use. Iodine tablets work similarly but leave a taste and are not recommended for pregnant women or thyroid conditions. Portable filters rated NSF 53 or NSF 58 remove protozoa and bacteria but most do not remove viruses — pair a filter with chemical disinfection in high-risk situations. UV purifiers (SteriPen and similar) disrupt viral and bacterial DNA effectively but require clear water and battery power. No single method is universally best; keep at least two methods on hand.
How much to actually store
One gallon per person per day is a minimum planning figure for drinking and basic sanitation. Active adults in warm weather need closer to one and a half gallons. Children, nursing mothers, and ill individuals need more. Add at least a half gallon per day per pet. Budget separately for hygiene water (tooth brushing, wound cleaning, limited dish rinsing) beyond the drinking estimate. A two-week supply for two adults and one dog is roughly 30 gallons as a starting target — a 30-gallon food-grade drum stored in a cool location covers most realistic outage scenarios.
Storage location and rotation
Store water where temperature is stable, containers are protected from sunlight, and leaks will not destroy flooring. Spread storage across more than one location if possible: pantry, closet, garage shelf, or under-bed containers. Do not place water next to gasoline, solvents, pesticides, or strong-smelling chemicals. Plastic can absorb odors, and damaged containers can contaminate the supply.
Rotation should be simple enough to remember. Commercial water can follow label dates. Home-filled containers should be inspected regularly for cloudiness, odor, leaks, cap damage, and algae. Label each container with fill date and source. If lifting heavy containers is difficult, use smaller jugs or a siphon pump. Water preparedness fails when the stored water is too heavy, hidden, or questionable to use.
How to treat water you have already stored
Sealed commercial bottled water and properly stored tap water are safe to drink directly from the container if seals are intact, the water is clear and odor-free, and the container has not been exposed to fuel, solvents, or extreme heat. Water treatment for stored water becomes necessary when it has been open for an extended period, has developed any cloudiness or musty smell, was filled from a source that is now under a boil-water advisory, or was stored in a container that may have been compromised.
The fastest treatment for stored water is boiling: bring it to a rolling boil for one minute (three minutes above 6,500 ft elevation) per CDC guidance. Boiling kills bacteria, viruses, and protozoa and does not require additional supplies. Let the water cool covered, then pour between clean containers to reintroduce oxygen and improve taste.
When boiling is not practical — no fuel, no power, or large volumes — disinfect with unscented household chlorine bleach (5–9% sodium hypochlorite) per EPA guidance: 8 drops (about 1/8 teaspoon) per gallon of clear water, or 16 drops per gallon if the water is cloudy or cold. Stir, cap loosely, and let it stand for 30 minutes. The water should have a faint chlorine smell when ready; if it does not, repeat the dose and wait another 15 minutes. Pre-filter cloudy water through a clean cloth or coffee filter before adding bleach so the disinfectant can work on the water rather than on suspended particles.
A third option is to run stored water through a gravity filter or pump filter rated NSF 53 or NSF 58 — useful when stored water is biologically suspect but otherwise visually clean. Pair the filter with chemical disinfection if there is any chance of viral contamination (sewage backflow, urban flooding, or international water sources). Filters alone will not address chemical contamination, fuel vapor absorption, or saltwater intrusion — those scenarios require fresh sealed water from outside the affected supply.
After treatment, transfer the water to a clean labeled container, note the treatment date and method on the label, and use it within a few days. Treated water is not "permanently sterilized" — once the container is opened or the chlorine dissipates, recontamination is possible. For longer-term re-storage, treat again before drinking.
Priority reset questions
Use this guide as a seasonal reset rather than a one-time read. Ask what changed since the last review: new address, new commute, new school, new medication, new pet, new vehicle, new weather risk, or new family responsibility. Preparedness plans drift out of date quietly. A short review keeps the system matched to the life you actually have now.
Then choose one action that can be finished today. Replace expired supplies, print a contact card, charge a battery, label a container, test one tool, or move gear to the place where it will be needed. Small completed actions beat large plans that stay theoretical.
Common mistakes
- Counting on filters while storing little or no ready-to-drink water.
- Storing water near chemicals or in containers that were not food-safe.
- Using questionable water for brushing teeth, baby formula, dishes, or medication.
- Forgetting that treatment may not remove chemical contamination after floods, spills, or industrial incidents.
Maintenance routine
Inspect containers every season for leaks, odor, discoloration, cracked caps, sun damage, and missing labels. Rotate commercial water according to label guidance and refresh home-filled containers on a schedule you can remember. After any advisory, flood, or plumbing incident, follow local health department instructions before using tap water again.
Scenario notes
For boil water advisories, use bottled, boiled, or treated water for drinking, cooking, tooth brushing, handwashing when directed, and baby formula. For power outages, remember that well pumps and treatment systems may stop working. For evacuation, carry enough water for the drive and first arrival period, then identify safe resupply points.
Filter and purification gear
For product picks that complement your water storage plan, see our guide to the best water filters for emergency kits — including pocket filters, gravity systems, and chemical backup options.
Authoritative references
This guide draws on Ready.gov water storage guidance, CDC emergency water safety, CDC hygiene guidance, and EPA emergency drinking water principles.
