City’s water system will have “free chlorine” disinfectant throughout June

The City of San Angelo’s Water Utilities Department will temporarily change the method of disinfection used in its public water supply, beginning June 1, according to a press release from the City’s Public Information Office.

The water department uses chloramine, a mixture of ammonia and chlorine, to disinfect water. Beginning June 1, and lasting through June 30, the department will use only chlorine, also known as “free chlorine.” The periodic, temporary conversion from chloramines to free chlorine – a normal procedure for municipal water systems – ensures water safety in distribution lines by ridding the mains of accumulated biological growths, thus yielding the highest quality of drinking water.

Citizens may see more flushing of fire hydrants by City staff during this process as certain water lines with low flow must be flushed more often to ensure the free chlorinated water is adequately moving through the system. The department does not like doing this during the City’s water conservation program, but in some areas it will be necessary, the release said.

Free chlorine is a stronger disinfectant than chloramine. As a result, water users may experience a slight change in the aesthetics of their water during the conversion, including a noticeable “chlorine odor” and slight discoloration. Most symptoms should lessen after a couple of weeks and do not affect the safety of the water supply.

The Water Utilities Department encourages kidney dialysis patients to speak with their equipment supplier as different types of equipment may have varying needs and require adjustments. The City has contacted local hospitals to alert them of the change.

Some reverse osmosis system membranes are not designed to work with water containing free chlorine. Owners of RO systems should consult their operation manuals or system manufacturers to ensure they will not be adversely affected by the change.

The processes most aquariums have for removing chloramines from water should do the same with free chlorine and need no adjustments. Even so, fish tank operators are encouraged to confirm that with their equipment supplier. Local pet stores have also been informed of the conversion.

The water department will monitor chlorine levels and water-quality standards in the distribution system on a daily basis to ensure the safety of the water and that all state and regulatory standards are met.