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Emergency Preparedness: Protecting Water Quality Before, During, and After a Flood Strikes

 
› Hazardous Waste
› Wastewater and Septic Systems
› Drinking Water
› For More Information

Floods can have disastrous impacts on people and property, including loss of life, destruction of houses and other buildings, and displacement of those whose homes are flooded.


Floods can also have dire effects on public health and the environment, particularly water quality. Containers with hazardous materials may be displaced and their contents spill into lakes and streams. Wastewater and septic systems may be overloaded and compromised. Contaminated flood waters may seep into ground water, which supplies drinking water for 95% of Idaho citizens.


Through education and planning, we can minimize flood-related threats to public health and the environment.
 
 Hazardous Materials: Follow these precautions  before a flood occurs

One of the most common problems after a flood is displacement of drums, tanks, and other containers that hold hazardous materials. To minimize contamination from these types of containers, follow these precautions:

  • Clearly identify and label contents of tanks, drums, or other containers, especially when materials are placed in other than original containers.
  • Place your name and address on larger fuel and propane tanks to facilitate identification of their contents and their return if they become displaced.
  • Store drums and smaller containers in areas that are least susceptible to rising and receding flood waters. When possible, contain in fenced areas, cabinets, or storerooms.
  • Make sure containment vaults for underground storage tanks have been engineered properly to prevent tanks from floating out of the ground if contents are lighter than water.
  • Minimize the amounts and types of materials kept on the premises. Purchase only what you need. Properly dispose of excess materials at hazardous waste collection centers. Contact the Idaho State Department of Agriculture to periodically dispose of old, expired, or unwanted agricultural chemicals.
 
 Wastewater and Septic Systems: Plan ahead to address a flood event

Wastewater and septic systems can become overloaded during floods, which can result in the spread of bacteria and other contaminants into the surrounding area, drinking water wells, and other waters. Follow these tips to address flood damage:

  • Identify at what water level your system can become compromised and prepare an emergency response plan.
  • Do not pump your tank when the drainfield is flooded or saturated. Pumping could cause the tank to float out of the ground and may damage the inlet and outlet pipes. The best solution is to plug all drains in the basement and drastically reduce water use in your house during the flood.
  • Do not use the sewage system until water in your soil absorption field is lower than the water level around the house.
  • Have your septic tank professionally inspected and serviced if you suspect damage. Signs of damage include settling or an inability to accept water. Most septic tanks are not damaged by flooding since they are below ground and completely covered. However, septic tanks and pump chambers can fill with silt and debris, and must be professionally cleaned. If the soil absorption field is clogged, a new system may have to be installed or the wastewater diverted to a replacement drainfield if one exists.
 
 Drinking Water: Make sure the water you drink is safe

During a flood, surface waters that inundate an area may contaminate drinking water wells and systems. Follow these precautions:

  • If your private well is flooded, assume the water in your home is contaminated.
  • It is recommended that you have your well tested for bacteria and other contaminants before returning it to service. Direct questions about testing to your public health district.
  • Use care around electrical connections. Have the well’s wiring system checked by a qualified electrician, well contractor, or pump contractor.
  • While water is being tested, if you choose to drink water from your well, boil or treat the water to kill harmful bacteria and parasites. Bringing water to a rolling boil for one minute will kill most organisms. Or you may prefer to drink bottled water from a reliable source.
  • Infants and pregnant women should use bottled water instead of boiled tap water for drinking and cooking. Boiling concentrates levels of nitrate in water. Use bottled water for preparing infant formula for children six months of age and younger.
  • Do not use contaminated water to wash dishes, brush teeth, wash and prepare food, or make ice.
  • If you are on public water, listen for public announcements on the safety of the municipal water supply. The water system will let you know, through local media, if your water is not safe.

Learn more about how to protect your drinking water:

After the Flood: Protecting Your Drinking Water

(DEQ Fact Sheet: pdf 57 kb, 5 pages)

Above normal snowpack plus last summer’s wildfires may signal spring flooding
(Extract from Drinking Water Newsletter, March 2008: pdf 228 kb, 1 page)

 
 For More Information
›

Floods - What You Should Know

Centers for Disease Control and Prevention Web site
›

Flood

Federal Emergency Management Agency Web site
›

Flash Floods and Floods

National Oceanic and Atmospheric Administration National Weather Service Web site

›

What to Do After the Flood -Emergency Disinfection of Wells that have been Flooded

U.S. Environmental Protection Agency Web site

›

Emergency Disinfection of Water

U.S. Environmental Protection Agency Web site

›

Safe Drinking Water Hotline: 1-800-426-4791

U.S. Environmental Protection Agency Hotline and Web site

   



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