Water Emergency Preparedness

A water emergency is more common than most people think. A boil-water advisory, a broken main, a well that floods, a treatment-plant failure — any of these can make the water that comes out of your tap unsafe. The EPA and CDC treat water preparedness as a core of household readiness: store it, know how to make it safe, and know how to keep the household hydrated when the tap is not an option. This guide covers how much to store, how to treat water when the supply is suspect, and what to do during a boil-water advisory.

Store water before you need it

The EPA recommends storing at least one gallon of water per person per day for at least three days — two for drinking and cooking, two for sanitation. For a household of four, that is 12 gallons for three days. Store it in food-grade containers that have never held anything toxic — never use milk jugs or containers that held anything non-food. You can buy dedicated water containers or use thoroughly washed two-liter soda bottles. Date each container and rotate the water every six months. If you rely on a well, store more, because a power outage can stop the pump and the water at the same time.

Keep some water in multiple locations — the pantry, a closet, the basement — so one inaccessible room does not leave the household dry. Store it in a cool, dark place. Do not store it near gasoline, pesticides, or anything with a strong odor, because some plastics can absorb smells. The plan is to have safe water before the tap is not safe, and the storage is the plan.

Know how to treat suspect water

If the tap water is suspect and you have no stored water, you can make water safe in three ways: boiling, chlorination, or filtration. The CDC recommends boiling as the most reliable method for most situations: bring water to a rolling boil for one minute (three minutes at altitudes above 6,500 feet), let it cool, and store it in clean containers. Boiling kills the organisms most likely to make you sick but does not remove chemical contamination — if the advisory is chemical, do not use the water at all.

If boiling is not possible, chlorination is the backup. Use unscented household liquid bleach (5 to 6 percent sodium hypochlorite) that has not expired; the EPA publishes dosing tables, but a common rule is 8 drops per gallon of clear water, 16 drops if cloudy. Stir, let it stand for 30 minutes, and it should have a slight chlorine smell. If it does not, repeat once; if it still does not, do not use it. A water filter rated for the contaminant is a third option, but know its limits — a household pitcher filter does not remove the organisms a boil advisory is about. The plan is to know which method fits the emergency, not to improvise one.

During a boil-water advisory

A boil-water advisory means the water may be contaminated and should be boiled before drinking, cooking, or brushing teeth. Use boiled or bottled water for drinking, making ice, brushing teeth, washing produce, and preparing formula. The CDC recommends not using the water for any of these unless it is treated. It is usually safe for showering, as long as you do not swallow it, but avoid baths for infants and young children who might swallow it. Do not use ice from the automatic ice maker until the advisory is lifted; throw out any ice made during the advisory.

If you have a baby or someone immunocompromised, use bottled water rather than boiled tap if you can, because the margin for them is smaller. Keep hand sanitizer on hand for washing hands when the water is not safe. Listen to your utility for the all-clear, because the advisory can last days. The plan is to treat every glass as suspect until officials say it is not.

If the water is off entirely

If the supply is off — a broken main, a power outage at the pump — your stored water is the household's water. Use it for drinking and essential sanitation first. The CDC offers guidance on rationing: do not ration drinking water; drink what you need and prioritize hydration, because dehydration is more dangerous than running out. Use alternatives for sanitation: hand sanitizer, baby wipes, and a bucket of water from a safe source if you can get one. If you have a pool, that water is for sanitation only, not drinking, unless you treat it.

Fill the bathtub with water before a known event if you have warning, but the CDC notes that this water is for sanitation, not drinking, because the tub and its plumbing are not food-grade. If you use it, treat it before drinking if you must. The plan for a water outage is the same as for any supply disruption: have the buffer before the disruption, know how to extend it, and do not let a water emergency become a medical one.

After the advisory is lifted

When your utility lifts the advisory, flush the pipes. Run cold taps for several minutes, and follow any instructions from your utility about flushing more or less. Run water through the lines until it runs clear if it was discolored. Replace any filter cartridges that were in use during the advisory, because they may have trapped contaminants. Throw out ice made during the advisory and clean the ice maker. Run the dishwasher empty once. The recovery is a set of steps that get the household back to safe water, and the plan is what kept you hydrated until they were done.

Review your water plan each season. Rotate the stored water, check the bleach for expiration, and confirm the containers are sealed. The water emergency that gives an advisory is the one you can plan for, and the stored water and the treatment knowledge are the plan.

This is planning guidance, not emergency advice. In an emergency, call 911. See a mistake? Report it.

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