Emergency Water Preparedness
How to Store Well Water for Emergencies
Plan for private-well power outages, safe pre-storage, testing after floods or repairs, and the limits of treating questionable well water.
Direct answer
Store well water while testing and normal system conditions indicate it is safe, before an outage stops the pump. Use clean, sanitized food-grade containers and replace self-filled water every six months. After flooding, repairs, or suspected contamination, use a safe alternative until the well has been assessed and tested under local health-department guidance.
Questions This Guide Answers
Can I store water from my private well for emergencies?
Store well water when testing and normal system conditions indicate it is safe, using washed and sanitized food-grade containers. Fill before an outage stops the pump and replace self-filled water every six months; do not store suspect well water as ready-to-drink supply.
Full guidance: Store water from a source you already trust · Sources: CDC — Guidelines for Testing Well Water; CDC — Create and Store an Emergency Water Supply
Why do I need stored water if I already have a well?
Most private wells rely on an electric pump, so a power outage can stop delivery even when the well still contains water. A pressure tank has limited usable drawdown; PHS recommends safe water stored before the event as the primary well-water backup.
Full guidance: A well can stop delivering water when power fails · Sources: CDC — Guidelines for Testing Well Water
What well-water tests should I plan before relying on it for storage?
CDC recommends at least annual testing for total coliform bacteria, nitrates, total dissolved solids and pH. Ask your health department about additional local contaminants and testing after flooding, repairs or changes in taste, color or smell, and use a state-certified laboratory.
Full guidance: Store water from a source you already trust · Sources: CDC — Guidelines for Testing Well Water
Can I drink well water after a flood if it looks clear?
Do not drink suspect well water after flooding just because it looks clear. Use a safe alternative and follow local health-department instructions for assessment, disinfection and testing; floodwater may introduce both germs and chemicals.
Full guidance: After flooding or suspected contamination · Sources: CDC — Guidelines for Testing Well Water; EPA — Emergency Disinfection of Drinking Water
Does shock-chlorinating a well remove chemical contamination?
Shock chlorination addresses certain microbial contamination when performed correctly; it does not remove chemical contamination. Well treatment requires exact local instructions, flushing and testing, so use a safe alternative while a suspect well is being assessed.
Full guidance: After flooding or suspected contamination · Sources: EPA — Emergency Disinfection of Drinking Water
A well can stop delivering water when power fails
Most private wells use an electric pump. An outage may leave water in the well but no way to bring it into the house. Pressure tanks provide only limited drawdown, not a long-term supply. Store water before a forecast outage and decide in advance how you will power the pump safely if that is part of your plan.
Do not connect a generator to household wiring without properly installed transfer equipment. CPSC warns against backfeeding, which can cause electrocution and fire. Generator placement and carbon-monoxide safety are critical. A stored-water plan is often simpler and safer for short outages.
Store water from a source you already trust
Private-well owners are responsible for monitoring their water. CDC recommends testing at least annually for total coliform bacteria, nitrates, total dissolved solids, and pH, plus locally relevant contaminants. Check the well for mechanical problems each spring. Additional tests and more frequent testing depend on local geology, land use, and well history; ask your local or state health department and use a certified laboratory. Test after flooding, repairs, or a change in taste, odor, or color, and keep the results.
Fill clean, sanitized food-grade containers while the well is operating normally and testing indicates it is safe. Follow the same six-month replacement guidance for self-filled water. Do not put untreated water from a flooded or suspect well into your drinking-water reserve.
After flooding or suspected contamination
Keep people and pets from drinking suspect well water. Contact your county or state health department for well inspection, sampling, and disinfection instructions. Floodwater can introduce pathogens and chemicals; appearance alone cannot establish safety. Shock chlorination addresses certain microbial contamination when performed correctly, but it does not remove chemicals and requires a post-treatment flush and testing process. It is a well-system procedure, not a shortcut for treating a drinking glass.
Official guidance and PHS recommendation
Official guidance: EPA provides private well information; CDC explains well risks, testing, and maintenance.
PHS practical recommendation: Treat “safe water stored before the event” as the primary well-water backup. Pair it with a tested power plan only if you can run the pump within its electrical and generator requirements. Keep a local lab and health-department contact in your household records.
Common mistakes
- Assuming a well is safe because the water is clear.
- Waiting until the power is out to discover the pump cannot run.
- Using household bleach or pool chemicals to shock a well without exact local instructions.
- Assuming filtration or boiling removes chemical contamination.
If normal tap water fails
If my normal tap water is unavailable or unsafe, where will my next water come from? Municipal service can be disrupted by power outages, main breaks, loss of pressure, treatment-system problems, flooding, contamination or infrastructure damage. A private well may still contain groundwater while its electric pump cannot run.
- Unavailable: obtain water from another safe source; a treatment device cannot produce water from a dry tap.
- Microbiologically unsafe: treatment may be possible; follow the actual advisory and appropriate treatment guidance.
- Chemically or otherwise dangerously contaminated: ordinary filtering, boiling and disinfection may not make it safe. Use another safe source and follow public-health instructions.
A boil-water advisory, do-not-drink advisory and do-not-use advisory are different. A do-not-use notice can prohibit all contact; do not substitute boiling for the stated restriction. See CDC’s drinking-water advisory guidance.