Is well water safe to drink after flooding?Nearly five years after historic levels of flooding, Iowans are again preparing for the encroachment of floodwaters from rivers in the eastern part of the state. Nancy Hall, environmental microbiology manager for the State Hygienic Laboratory, said that those who have private wells should take precautions to prevent illnesses.
"If floodwaters have been over the well, the drinking water is not safe to drink," Hall said. "This water also should not be used for teeth brushing or showering.”
Private well systems pose a potential health risk if they have been covered by floodwaters because this water may contain fecal material and other contaminants from overflowing sewage systems, agricultural run-off and industrial byproducts.
During well flooding, Hall recommends using drinking water from a safe source, such as bringing water from a city supply or buying bottled water that is intended for drinking. Hall said that common illnesses that are caused by exposure to flood waters may include skin and tissue infections following superficial cuts, scratches, abrasions or insect bites; deep tissue infections following puncture wounds or trauma; and gastrointestinal illness following ingestion of contaminated water or food.
For those in flooded areas, the following public health measures are recommended:
- Always wash hands with soap and water before eating food and after handling articles contaminated with flood water.
- Avoid prolonged exposure to flood water.
- Wear protective gloves, boots and eye wear.
- Work cautiously, rest frequently and eat a balanced diet.
- Bathe or shower in clean water as soon as possible after exposure to flood water.
- Use insect repellents to discourage biting insects.
Follow basic hygiene practices.
- Obtain water from a known safe public water supply or buy bottled water.
- Haul and store drinking water in clean containers (not old milk or juice jugs).
- As a last resort, clear water may be treated for drinking by boiling it for one minute or by adding eight drops of unscented household bleach per gallon (mix well and wait at least 30 minutes before drinking). If not clear, filter it through a clean cloth, paper towel, or coffee filter OR allow it to settle and pull off the clear water; then boil or add eight drops of bleach as described above.
Ensure drinking water is safe.
- Don’t drink water from flooded wells unless the well has been properly disinfected and then tested for drinking safety.
- Contact your local county health department for a free flood sampling container and advice.
- AFTER flood waters have receded, shock chlorinate and flush wells BEFORE submitting a sample to the Laboratory for testing.
- Shallow wells (less than 100 feet deep) can be contaminated from nearby flooding and should be tested to ensure a safe supply of drinking water.
Private well owners should take additional precautions.
- Discard all containers with signs of leakage or damage.
- Foods in paper, cardboard or flexible plastic must be thrown away.
- Discard foods in corked bottles, canisters and screw-capped jars or bottles.
- Canned goods may be sanitized and used if the label is removed, the can is washed in hot, soapy water and the item is identified with a permanent marking pen.
- Solutions containing chlorine bleach are not recommended for cleaning cans because they accelerate rusting.
- Leafy vegetables cannot be washed adequately to be eaten raw.
- Thawed foods should not be refrozen.
Make sure food is safe to eat.
- Use non-sudsing cleaning products (Spic and Span, Trisodium Phosphate, etc.) to wash interior surfaces.
- Use commercial cleaners for fabrics.
- Disinfect sewage-contaminated areas with a solution of household bleach (1/4 cup per gallon of water).
- Consult professional carpet cleaners before attempting to salvage carpet or carpet pads.
- Remove flood damaged sheet rock to permit studs and insulation to dry thoroughly.
- Remove silt, sludge and debris from ductwork and dry it thoroughly before reactivating heating/air conditioning units.
Clean up after a flood in a way that prevents illnesses.
- Private well water testing for individuals through county health departments, and
- Consultation on disease prevention, water and food safety, and disinfection of environmental surfaces.
The State Hygienic Laboratory provides additional assistance, including:
- The University of Iowa Flood Updates 2013
- Iowa Department of Public Health Flood-related Disease Precautions and Information
- Iowa Department of Natural Resources
- Iowa State University County Extension offices
- County health departments
- American Red Cross
- Federal Emergency Management Agency (FEMA)