United States
Environmental Protection
Agency
What to Do After the Flood
WARNING!
DO NOT TURN ON THE PUMP
There is danger of electrical shock and
damage to your well or pump
if they have been flooded
WARNING!
DO NOT WASH WITH WELL WATER
People drinking or washing with water
from a private well that has been flooded
will risk getting sick.
Drilled, driven or bored wells are best disinfected
by a well or pump contractor, because it is difficult
for the private owner to thoroughly disinfect these
wells.
If you suspect that your well may be contami-
nated, contact your local or state health department
or agriculture extension agent for specific advice on
disinfecting your well. The suggestions below are
intended to supplement flood precautions issued by
State and local health authorities.
Well and Pump Inspection
Flood Conditions at the Well - Swiftly moving flood water can carry large debris that could
loosen well hardware, dislodge well construction materials or distort casing. Coarse sediment
in the flood waters could erode pump components. If the well is not tightly capped, sediment
and flood water could enter the well and contaminate it. Wells that are more than 10 years old or
less than 50 feet deep are likely to be contaminated, even if there is no apparent damage. Floods
may cause some wells to collapse.
Electrical System - After flood waters have receded and the pump and electrical system have
dried, do not turn on the equipment until the wiring system has been checked by a qualified
electrician, well contractor, or pump contractor. If the pump's control box was submerged dur-
ing the flood all electrical components must be dry before electrical service can be restored. Get
assistance in turning the pump on from a well or pump contractor.
Pump Operation - AH pumps and their electrical components can be damaged by sediment
and flood water. The pump including the valves and gears will need to be cleaned of silt and
sand. If pumps are not cleaned and properly lubricated they can bum out. Get assistance from a
well or pump contractor who will be able to clean, repair or maintain different types of pumps.
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Emergency Disinfection of Wells that have been Flooded
Before Disinfection: Check the condition of your well. Make sure there is
no exposed or damaged wiring. If you notice any damage, call a professional
before the disinfection process.
Stepl
If your water is muddy or cloudy, run the water from an
outside spigot with a hose attached until the water becomes
clear and free of sediments.
Materials Needed:
• One gallon of non-scent-
ed household liquid bleach;
• rubber gloves;
• eye protection;
• old clothes; and
• a funnel.
Step 2
Determine what type of well you have and how to pour the bleach into
the well. Some wells have a sanitary seal with either an air vent or a plug
that can be removed (a). If it is a bored or dug well, the entire cover can be
lifted off to provide a space for pouring the bleach into the well (b).
StepS
Take the gallon of bleach and funnel (if needed) and carefully pour the bleach down
| into the well casing.
Step 4
After the bleach has been added, run water from an outside
hose into the well casing until you smell chlorine coming from the hose. Then turn off the
outside hose.
StepS
Turn on all cold water faucets, inside and outside of house, until the chlorine
odor is detected in each faucet, then shut them all off. If you have a water treat-
ment system, switch it to bypass before turning on the indoor faucets.
Step 6
Wait 6 to 24 hours before turning the faucets back on. It is important not to drink, cook,
• bathe or wash with this water during the time period — it contains high amounts of chlorine.
Step?
Once the waiting period is up, turn on an outside spigot with hose attached and
run the water into a safe area where it will not disturb plants, lakes, streams or septic
tanks. Run the water until there is no longer a chlorine odor. Turn the water off.
StepS
The system should now be disinfected, and you can now use the water.
Step 9
Have your water tested for bacteria 7 to 10 days after disinfection.
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Sampling and Testing the Well Water
Contact the local health department to have well
water sampled and tested for contamination. Or, call
your state laboratory certification officer to find a cer-
tified lab near you. You can get this number from the
Safe Drinking Water Hotline (1-800-426-4791).
If the health department issues sterile bottles for
the private well owner to collect water samples, fol-
low all instructions for the use of these bottles.
After the pump is back in operation, the health de-
partment should sample and test the water at regular
intervals.
CAUTION: Because of the extensive flood area
and the speed and direction of ground water
flow, your well may not be a safe source of water
for many months after the flood. The well can
become contaminated with bacteria or other
contaminants. Waste water from malfunction-
ing septic tanks or chemicals seeping into the
ground can contaminate the ground water even
after the water was tested and found to be safe.
It will be necessary to take long range precau-
tions, including repeated testing, to protect the
safety of drinking water.
CONCERNS AND ADVISORIES
If in doubt about the well water supply, follow health department drinking and bathing advisories.
Remember that there is a danger of electrical shock from
any electrical device that has been flooded; consult a certi-
fied electrician. Rubber boots and gloves are not adequate
protection from electric shock.
Well disinfection will not provide protection from
pesticides, heavy metals and other types of non-biological
contamination. If such contamination is suspected, due to
the nearness of these contaminant sources, special treat-
ment is required.
Information on home water treatment units (also called point-of-use and point-of-entry units) is available
from US EPA by phoning the Safe Drinking Water Hotline (1-800-426-4791)
If you observe chemical containers (including barrels and drums) that have moved to your property, call your
state or county health department or the Superfund Hotline (1-800-424-9346).
For information on long-term water quality conditions in the area, consult the state or county health depart-
ment.
Well owners may have information about the construction, or testing of their well and this information will
be helpful to the health department in determining water quality conditions.
Septic systems should not be used immediately after floods. Drain fields will not work until underground
water has receded. Septic lines may have broken during the flood.
OFFICE OF WATER (4606 M)
www.epa.gov/safewater
EPA 816-F-05-021 AUGUST 2005
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