State Health Department: Flooding Could Impact Some Drinking Water Supplies

Private wells that have been flooded should be disinfected before use

ALBANY, N.Y. (August 31, 2011) – Following extensive flooding in many areas of New York State in the wake of Hurricane Irene, the State Health Department today advised New Yorkers whose private water well supplies that have been impacted by storms to take appropriate precautions to ensure their water is safe. Those who rely on public drinking water systems should follow instructions issued by their local health departments.

"Health and Safety is always the top priority in cases of natural disasters and people should be aware that the impact of the hurricane could potentially affect their drinking water," State Health Commissioner Nirav R. Shah, M.D., M.P.H. said. "We urge people to take precautions to protect their health and safety, especially if they use private drinking water wells that have been submerged by flood waters or if the quality of the water has noticeably changed."

Private Well Water

If the area around a private well has been flooded or there is any suspicion or risk that the well has been contaminated from flood waters, consumers are advised to stop drinking, cooking, brushing teeth and bathing with the well water and disinfect the well. Wells in flooded areas may be contaminated with waterborne germs that can cause serious illness. Until the well has been properly disinfected and tested, water used for these purposes should be disinfected as mentioned below or bottled water should be used.

Warning signs that a well may be unsafe include: debris, mud or water and mud stains that indicate the well was flooded; erosion or instability in the ground surface around the well; damage to the well casing; a loose well cap; unusual odor, taste or appearance of the well water; or any visible electrical wires or components.

If the well has been or is suspected of being flooded, the well pump should not be turned on until the well has been thoroughly assessed and repaired as needed by a plumber or other well professional. Beware of electrical shock if your basement or electrical system has been flooded. Also, no one should drink, bathe, brush teeth or cook with well water after a flood until the well has been restored by proper disinfection and flushing. Unless there is indication that the well has been impacted by spilled fuels, oil or other chemicals, then it should be safe to continue to use water for flushing toilets.

Until the well is properly disinfected, bottled water should be used for washing, drinking or cooking. Tap water can be used if it has been disinfected by one of the following methods:

  • Disinfection by boiling the water – This method produces the safest water. Bring the water to a rolling boil and maintain a full boil for one minute. After cooling, it is recommended that oxygen be restored to the water by pouring it back and forth between two containers – this will also improve the taste.
  • Disinfection with Iodine or Chlorine tablets – First, check the expiration of the tablets before using and then follow package directions. One tablet is usually sufficient for one quart of water; double the dose if the water is cloudy.

For more information on disinfecting contaminated water, see:

Disinfecting a Well

A New York State Department of Environmental Conservation (DEC) registered well driller can be contacted for information about disinfecting your well and additional treatment if needed. For do-it-your-selfers, information about disinfecting a well, including step-by-step instructions, can be found at:

After a well has been properly disinfected and chlorine has been flushed out of the water system, the water should be tested for bacteriological contamination. A list of labs that have been certified for drinking water testing can be found at: Continue to disinfect any water used for drinking or food preparation, or use bottled water until sampling has shown the water to be safe and free of contamination. You should consider retesting your well several weeks after flooding since groundwater contamination after a flood may impact the well.

Public Drinking Water Supplies

New York State and local health department officials and water suppliers are aware that turbidity levels are significantly higher than normal as a result of Hurricane Irene, and that contamination by untreated sewage is present in many of the impacted waterways. Water suppliers are taking appropriate steps to ensure that the water is adequately treated, such as monitoring more frequently, increasing chemical treatment, and ensuring adequate filtration. Drinking water utilities (community water systems) are required to follow specific regulations and procedures to ensure water is safe for consumption and use and these requirements continue to be in full effect during the aftermath of Hurricane Irene.

Drinking water utilities in New York State are required to monitor water quality levels for a variety of man-made chemicals, naturally-occurring contaminants, physical characteristics and microbial pathogens and immediately report any public health hazards or emergency conditions to their county health department or a State Department of Health (DOH) district office that regulates the utility. The utility will work with the appropriate health department to identify and initiate an appropriate response action and must notify of any changes in conditions until the problem is resolved. These utilities are monitored by the local health departments or DOH on a regular basis, and Health Departments are performing heightened oversight of public water suppliers during and after the Irene flooding.

If conditions warrant, the local health department may issue a boil water advisory, which typically lasts 24-48 hours, but could be extended if water is not deemed safe to drink or should not be used for cooking. Consumers should adhere to the advisory until the local health department announces that it has been lifted. Information for consumers on responding to a boil water notice is available at

A booklet containing information for homeowners and others following a flood or other severe weather event is available at:

Additional safety tips can be found here.