SAN ANGELO, Texas — The San Angelo Water Plant, every June, switches the end of their filtration process by injecting the water with Free Chlorine instead of Cloromine which is used the other 11 months of the year.
Plant Operations Manager Tymn Combest says, “San Angelo uses chloramine as its primary disinfectant. When you use chloramine over a period of time you tend to build up biofilm in the distribution mains and also nitrification and so we’ll switch for one month in June normally to free chlorine which is a stronger oxidant and it will go in there and kind of clean out the biofilm destroy the biofilm and pretty much freshen up the water system.”
San Angelo gets its water from lakes and rivers, home to dissolved organics that can lead to cancer-causing problems. Chloramine is needed to kill off these organics.
“If you add chlorine to organics it will form trihalomethanes or carcinogenic chemicals but if you add ammonia to it first then that chlorine can’t bind up with the organics and form carcinogens so that’s why we use chloramine in San Angelo to prevent the formation of cancer-causing chemicals.”
When adding Chloramine to the water though, it creates a film-like coating on the inner walls of water pipes throughout the city. Combest says in order to get rid of that coating and restore the inner pipework, they must run water through the pipes that only have chlorine in them rather than the additional ammonia needed to form chloramine.
For the remainder of June, there may be a slight pool-like odor to the water coming out of your faucets, but it is still safe to use.