Why is my water system conducting a free chlorine conversion?

A free chlorine conversion is typically conducted for two primary reasons:

  • It is often conducted as a preventative maintenance measure to kill bacteria that can make the maintenance of disinfection residual problematic. A film can form in the distribution system piping that can contain bacteria which use ammonia as a food source. These bacteria in this film are harmless to people. When the water system stops adding ammonia, the bacteria starve. Therefore, a periodic conversion to free chlorine is effective for inactivating these types of bacteria in piping with biofilm by interrupting the supply of ammonia and can help prevent subsequent issues from occurring.
  • In rare occasions, if the distribution system receives a moderate to excessive amount of ammonia over long periods of time, bacteria using ammonia as a food source can bloom and cause a loss of disinfectant residual. As a result, the water system may not be able to maintain the minimum required disinfectant residual in the distribution system, and may receive complaints regarding taste/odor. The conversion to free chlorine, in conjunction with increased flushing activities, assists in removing excess film from the distribution system and also starves these bacteria. The chlorine conversion helps the system return to an environment where the disinfectant residual can be maintained.

Show All Answers

1. Why is drinking water disinfected?
2. What are the drinking water disinfection requirements in Texas?
3. What is chloramine?
4. Why is my public water system using chloramine?
5. What are disinfection by-products?
6. Is chloramine safe?
7. What is a free chlorine conversion?
8. Why is my water system conducting a free chlorine conversion?
9. Are there any disadvantages to a free chlorine conversion?