Disinfection and chlorination of a well

Chlorine can eliminate bacteria in your well, pump and distribution system.  Chlorine has a preservation period of six months, thus make sure to use fresh Javel water.  There are two common processes for chlorination: shock chlorination and continual chlorination.  For shock chlorination, add a large quantity of chlorine – Javel water - to the well water before you pump it in the system.  For continuous chlorination, add small amounts of chlorine frequently to the water supply.

Chlorination, steps to be followed:

  1. Pour the required amount of chlorine into the well air vent or by removing the well cap.
  2. Mix the well water by using a clean hose to pump the chlorinated water back into the well.  This will rinse the tubing and the water mains that are above water level.
  3. After you pour chlorine into the water, remove or by-pass any carbon filters in the system.  These filters remove chlorine from the water and any pipe beyond the filter will not be disinfected.
  4. Replace the filter to avoid another system contamination.
  5. Run water through all taps until a strong chlorine smell is detected.  However, take note that chlorine smell can become imperceptible to your nose.
  6. If there is no chlorine smell, or if it is very faint, add some Javel water in the well.
  7. Drain the water heater and fill it with chlorinated water.
  8. Backflush the water softener and all the filters (except carbon filters).
  9. Let the chlorinated water settle in the system for at least 12 hours.
  10. Eliminate the rest of the chlorinated water from the system through an outside hose and let the water run on the ground.  Also, leave the taps running for awhile.
  11. Avoid sending too much chlorine to your septic tank, because it will kill the bacteria necessary for breaking down wastes.
  12. Do not drink water until the results prove it is safe to drink.
  13. Temporary Solution: small quantities of water can be treated: by boiling water during 1 to 5 minutes, or by adding and mixing 2 drops of chlorine per liter of water and letting it settle for 30 minutes.

Well water quality (2) Analysis repetition

  1. 48 hours after chlorination, take a water sample for analysis.
  2. Two consecutive negative analysis on samples taken over a period of 1 to 3 weeks probably indicate that the treatment has been effective.
  3. If bacteria are still present, repeat chlorination and analysis.
  4. If the steps listed fail, it is strongly recommended that you determine the source of permanent contamination and try to correct it, possibly with professional help.  A new well or a water disinfection device could be needed.



Well disinfection with javel bleach

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1) Drilled well
2) Dug well