Flood Water / Sewage Back Up 

Public Health Advisory

Flood Water Contamination

Exposure to flood water that maybe contaminated with sewage:

The following recommendations emphasize avoiding contact with potentially contaminated flood waters and using appropriate precautions if contact is unavoidable.

If a basement or other areas have been flooded, it should be assumed that the water maybe contaminated with sewage. The Health Division strongly advises that individuals avoid contact with any standing water if at all possible. If a person comes in contact with potentially contaminated flood water, the following recommendation/precautions should be followed:

  • Keep all children and pets out of flood water
  • Wear waterproof boots, gloves, eye protection and clothes that are waterproof or disposable
  • Make sure all gas and electrical utilities to the affected area are turned off by Electric Light Co, or Gas Co before you enter flood water
  • Keep contact time with flood water at a minimum and avoid splashing
  • If there is contact, wash thoroughly with soap and water and launder clothes if possible
  • If an individual becomes ill with fever, nausea, vomiting, or diarrhea after exposure to possible contaminated flood water, contact your health care provider.

If you have any other questions, contact the Reading Health Division, at 781-942-9061

Procedures if Your Home Experienced a Back-up of Sewage or Flooding

Homes and Buildings

Flooded basements should be pumped out and disinfected. After the water is pumped out, solid wastes should be disposed of in a functioning sewage disposal system. All flooded floor and wall surfaces should be washed with a solution of one capful of household bleach for each gallon of water. Any household articles affected by flood waters should be washed with the same solution. Carpeting, mattresses and upholstered furniture should be disposed of or cleaned by a professional cleaner. (look in the Yellow Pages under "Fire Restoration").

If you have any direct contact with raw sewage while cleaning and you have any open wounds, we suggest that you contact your personal physician for recommendations on any preventative procedures.


Yards that have been contaminated by flooded sewage systems should be disinfected by a liberal application of lime. Children and animals should be kept away from limed areas until the lime is no longer visible.


Immersed food products should not be consumed. This applies to products that are not canned or bottled. These items are not affected but should be washed thoroughly with approved drinking water and a mild disinfecting solution and then rinsed prior to opening and use.

Look under Fire and Water Restoration in the Yellow Pages for companies that will disinfect after water and sewer overflows and/or flooding.


If the area over a well is under flood water, the recommended procedure for disinfection is as follows:

  1. Pour a solution of one gallon of water and one half gallon of three % to six % commercial bleach directly into the well.
  2. Open all faucets until there is an odor of chlorine apparent and then close all faucets for ten hours to allow the bleach to kill any bacteria present in the pipes, storage tank or well.
  3. Next, open all faucets and let the water run until the odor and taste of bleach have disappeared.
  4. Have a sample of water, taken 24 hours after disinfection, tested at a certified laboratory to determine that the water is suitable for use. A copy of a list of certified labs is available at the Health Division.
  5. This procedure results in a high level of chlorine so the water should not be used for drinking, cooking, watering livestock or irrigation until the chlorine taste and odor are no longer apparent. Use of bottled water or boiling water is suggested if you are unsure of the purity of your well water.

Boiling Water

If you must boil contaminated or potentially contaminated tap water, the water must be at a rolling boil for 5 minutes. (Reminder: The water is hot, allow 1 hour cooling time).