Thursday, February 29, 2024

What’s in my water?

An explainer on the differences between chlorine, chloramine ahead of Reno disinfection system conversion


RENO — The city of Reno is gearing up to switch its water disinfection process from using chlorine to chloramine at all well sites.

This change will make it easier for Reno to enhance its supply with water from other entities, i.e. Azle, Springtown and Walnut Creek Special Utility District. By using the same chemical mixture as those other water providers, city staff will not have to require residents to boil their water before using it after Reno gets additional water from those entities.

City leaders have been working toward getting the disinfection systems installed, and that project was expected to be finished by the second week of February. During this transition, curious Reno residents may be asking themselves a few questions — What is chloramine? How does it differ from chlorine? How will the change affect the water supply?

Most people probably understand that water coming from lakes or wells can contain harmful germs and may need to be cleaned before being used. Water can also be contaminated as it travels through pipes. Chlorine and chloramine are used to clean water and prevent illnesses like Salmonella, according to the Centers for Disease Control and Prevention.

“Chlorine and chloramine are both used as disinfectants when it comes to drinking water,” Reno Public Works Director Chris Albright said. “Free chlorine is a more potent disinfectant compared to chloramine. Free chlorine reacts quickly with micro-organisms and organic matter in water, providing rapid disinfection while chloramine is a more stable compound and has a longer-lasting disinfection effect. It is often used in situations where a residual disinfectant needs to be maintained throughout the distribution system.”

The CDC’s website states that both chlorination and chloramination make water safe to drink by killing germs. Chloramines, specifically, contain chlorine and ammonia, and the type of chloramine used to disinfect drinking water is monochloramine. Consuming water with less than 50 milligrams per liter of chloramine (though the normal range of disinfectant levels is 1-4 milligrams per liter) has not been known to affect a person’s health. However, some people may be more sensitive to chemicals than others.

Likewise, water with chlorine or chloramine is safe for pets that are mammals or birds, but not for fish, reptiles and amphibians which need water that doesn’t include a disinfectant, according to the CDC.

As far as taste and smell, water with chloramine may differ from the specific sensory reactions invoked by water with chlorine.

“Chloramine will generally produce fewer taste and odor issues in water than free chlorine,” Albright said.

Neither chlorine nor chloramine are new. They have been used as water disinfectants for decades in the U.S., starting in the first half of the 20th century, according to the CDC’s website. As for Reno, Albright suspects the city has been using chlorine as a disinfectant since the water system was installed.

“One of the primary reasons for treating groundwater with chlorine is to disinfect it and eliminate or reduce the presence of harmful microorganisms, such as bacteria, viruses and parasites,” Albright said. “Chlorine is effective in killing or inactivating a wide range of pathogens, making the water safe for consumption. Chlorine can create a residual disinfectant in the water that continues to provide protection as the water travels through distribution systems. This residual helps prevent the regrowth of microorganisms and maintains water quality until it reaches the consumer's tap.”

The CDC’s website states that water providers can temporarily switch from chloramine to chlorine to get rid of biofilm, or slime, that can develop in pipes and makes disinfection more difficult. Alternatively, chloramine can last longer in pipes than chlorine and create fewer chemicals, or disinfection by-products, when reacting to particularly dirty water.

For more information on chlorine and chloramine, visit the CDC’s website at online.