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Well Water After a Power Outage: Is It Safe and What to Do

Updated November 1, 2026 · General information, not medical or plumbing advice

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During a long outage

• Use bottled or stored water for drinking, cooking and bathing (NEHA). NEHA also suggests storing safe water for three days ahead of time.
• Don't open faucets, shower or flush toilets in an extended outage, say the Chester County health officials. Even if the storage tank holds water, drawing from it depressurizes the system.
• Before an expected outage, NEHA says to turn off power to the pump, shut off the water with shut-off valves, and unplug filtration systems and note the time.

When the power comes back

1. Keep using bottled or stored water. NEHA says to do this until you know the water is safe.
2. Turn the pump power off, then inspect. NEHA says to make sure power to the pump is off before you inspect the well area, because of the danger of electrical shock. It lists wires and connectors, the well cap, seals and vents, casing and piping, well house equipment, indoor piping and tanks, gaps around the casing, debris, and spilled chemicals or gasoline. Call a qualified electrician for damaged wires. The CDC says a qualified electrician, well contractor or pump contractor should check the wiring before power is restored to a flooded well.
3. Turn the pump on if there are no issues, and if it will not start, turn off the electricity and call a licensed well contractor (NEHA).
4. Flush the well. NEHA says to run the pump until the water runs clear, using an outside faucet and a hose that sends the water away from the septic system, public sewer, nearby surface water or animal habitats. If it does not run clear after several hours, call a licensed well contractor and keep using bottled water. NEHA also says not to pump water from another source into your well.
5. Protect your treatment system. NEHA says to disconnect or bypass household filters or softeners if there is no shut-off valve before or after the pressure tank. Chester County says to make sure a private treatment system is running properly once power returns.
6. Check pressure. NEHA says to listen for air escaping from a faucet with water spurting, and to watch your pressure gauge. Low pressure may recover once the pump is on, or a pipe may have burst. Call a licensed well contractor if either occurs. See well pump not working and well pressure tank.
7. Flush the household lines by letting the water run for a few minutes before drinking (Chester County).
8. Test. NEHA says to test for coliform bacteria and nitrate, and to ask your local health department about other contaminants of concern. Use bottled or stored water until the lab confirms the water is safe and repairs are done.
9. Disinfect if needed. NEHA says that if the water is contaminated or repairs were made, you may need to have the well professionally disinfected, then retest.

Chester County says that if the system lost all pressure and no water came out, check the water quality before drinking, and disinfecting the well may also be advisable. A positive bacteria result is covered in coliform bacteria in well water.

Plan for next time

NEHA suggests photographing and documenting all well components (tanks, pump, treatment and electrical parts), storing well documents where you can find them, keeping contact details for a licensed well contractor, your health department and a testing lab, and installing shut-off valves before and after the pressure tank. It suggests considering a generator connection if outages are frequent.

Common questions

Is well water safe to drink after a power outage?

Not automatically. The Chester County Health Department says pressure normally acts as a barrier, but during an outage, opening faucets lowers pressure, which can let bacteria and viruses enter. It says contamination can occur without any change in taste, odor or clarity. NEHA says to use bottled or stored water until you know your water is safe, and to test at a certified lab after an outage.

Should I use water, flush toilets or shower during a long outage?

Chester County says that during extended outages it is important to refrain from opening faucets, taking showers or flushing toilets, because drawing water from the storage tank depressurizes the system even if the tank holds water.

What do I do when the power comes back?

NEHA says to turn off power to the well pump while you inspect the well area, check for damage, then, if there are no issues, turn the pump on and flush by running the pump until the water runs clear, using an outside faucet and a hose that drains away from your septic system. Then test for coliform bacteria and nitrate. Chester County says to flush all lines for a few minutes before drinking, and to check any private treatment system is running properly.

Do I need to disinfect my well?

NEHA says testing will tell you if you need to disinfect. If the water is contaminated or repairs were performed, you may need to have the well professionally disinfected. The CDC says wells should be disinfected by a well or pump contractor because of safety concerns.

Can I run my well pump on a generator?

NEHA says to consider connecting your well pump to a generator if you have frequent outages. Pump and generator wiring is electrical work. Hire a licensed well contractor or electrician, and check local codes. The pages we opened do not give steps for that.

Related guides

• Well pump not working: outages and floods
• Coliform bacteria in well water
• Well water cloudy or brown after heavy rain