Whenever a home has been unoccupied for an extended period of time we recommend disinfecting the well, especially if the electricity has been turned off at any time during that period. This is a situation we see often in country houses and mobile homes in our North Central Florida area that are for sale and have sat empty on the market for a while. The culprit you are trying to eliminate is E Coli bacteria.

    Yes, you can test the water first for bacteria, but the time and expense of testing can sometimes be more trouble than if you just went ahead and disinfected the well. Your local health department can provide disinfection instructions. Plus, the odds are high that the test will be positive.

    Other situations that indicate well disinfection may be necessary are:

• After well or pump repairs.
• When the well has been flooded or near flood waters.
• When the water tastes different or has a strange odor.
• After doing plumbing repairs or the addition of piping or fixtures.
• Your well has had a previous history of bacterial contamination and has not been tested for a year or more.

    When the contamination is coming from a source underground, such as a nearby septic tank, the bacteria will likely return and you must deal with the source of the contamination to fix the problem. Improper plumbing installation that allows a cross connection is another way that bacteria can reoccur. Also, disinfection does not eliminate non-bacterial contaminations such as arsenic, radon, nitrates, or pesticides.

    And, of course, you should test the water after disinfection to confirm that it was successful. Usually it is, but we have occasionally come across a stubborn well that requires a second round to clear out all the bacteria. 

    Most county health departments in Florida provide water testing for a nominal fee, usually $30 to $40, and will give you instructions on how to properly collect the water sample. There are also state-certified private labs that can do the basic tests, and check for lead, iron, arsenic, and other contaminants for an additional fee.

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Here’s links to a collection of our other blog posts about WELLS:

• What is the blue dumbbell-shaped tank at the well equipment?

• What is the tank marked "potassium permanganate" in the water treatment system for? 

• Does an abandoned well need to be capped or removed?

• Does a homeowner need a permit to drill a water well on their property in Florida? 

• Is a high iron level in well water a health hazard?

• Should I test my well water for arsenic?

• What is the danger of radon in well water? 

• What size generator do I need to run my submersible well pump?

• Why would a well need to have a chlorinator/dechlorinator system? 

• Why does my well pump turn on and off every time I use water?

• What is the required water testing for an FHA, VA, or USDA mortgage application? 

     Visit our WELLS page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.