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New Hampshire Department of Environmental Services

Environmental Services Urges Safety of Drinking Water in Flooded Areas
Private Drinking Water Wells Susceptible to Flood Contamination

The New Hampshire Department of Environmental Services encourages residents to take precautions during and after the flooding, including protecting their drinking water. Flooding can cause the contamination of water with fecal matter from sewage systems, septic tanks, as well as contamination from oil, gasoline and other chemicals.

If you are on a public water system, check "Drinking Water Advisory" under ALERTS on to see if your system is under a boil order. If it is, please read the information below to ensure your water is safe to drink.

After a flood, private drinking water wells may have been contaminated by the floodwaters. Heavy precipitation tends to mobilize bacteria and thus highlight conditions of poor well construction. NHDES urges all private well owners who’s well has been flooded to boil their water for drinking and to have their well water quality tested after the floodwaters have receded.

How to make sure your drinking water is safe:

Additional safety tips during and after flooding:

  • Be aware of potential chemical hazards you may encounter during flood recovery. Floodwaters may have moved containers of solvents, petroleum, or other hazardous chemicals from their normal storage places. If any propane tanks (whether 20-pound tanks from a gas grill or household propane tank) are discovered, do not attempt to move them yourself. These represent a very real danger of fire or explosion and if found, police or fire departments should be contacted immediately. To report a hazardous materials/waste spill, call 271-3899; to report a petroleum spill, call (603) 271-3644; after hours call (603) 223-4381.
  • Car batteries, even those in floodwater, may still contain an electrical charge and should be removed with extreme caution by using insulated gloves. Avoid coming in contact with any acid that may have spilled from a damaged car battery.
  • Dams are at or near flood levels. If you should observe any areas of erosion or instability around a dam, report it immediately to 271-3406 or after hours at 1-800-852-3411.
  • Do not allow children to play in floodwaters, and do not allow them to play with toys that have been in floodwater until the toys have been disinfected. For disinfection, use 1/4 cup of bleach to one gallon of water.

For more information about environmental impacts from floodwaters, please contact the NH Department of Environmental Services at (603) 271-3503 or For public health information, please contact your local health department or the Division of Public Health Services at (603) 271-4496.



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NH Department of Environmental Services | 29 Hazen Drive | PO Box 95 | Concord, NH 03302-0095
(603) 271-3503 | TDD Access: Relay NH 1-800-735-2964 | Hours: M-F, 8am-4pm

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