Chloramine in Your Phoenix Shower: What It Is and What to Do About It

Phoenix switched from chlorine to chloramine disinfection as the primary residual disinfectant in the distribution system. Chloramine is formed by combining chlorine with ammonia at the treatment plant and provides a more stable disinfection residual over the long distribution lines that serve the Phoenix valley. The result for Phoenix homeowners is that the chemical smell most people associate with chlorine in a pool or a glass of tap water is actually chloramine, and chloramine behaves differently than free chlorine in a shower. It volatilizes more readily into hot steam. It does not respond to standard activated carbon the way chlorine does. And for households with respiratory sensitivities, it is the single most common complaint we hear before a whole-home filter install. This guide explains what chloramine is, why Phoenix uses it, and what treatment actually removes it at the shower. Verify current disinfection practices and residual levels with Phoenix Water Services at phoenix.gov/waterservices, as treatment protocols are subject to change.

What is chloramine and why does Phoenix use it instead of chlorine?

Chloramine is a chemical compound formed when chlorine reacts with ammonia. Water utilities add it intentionally during treatment because it maintains a disinfection residual over much longer distances than free chlorine. In a metro as geographically spread as Phoenix, water travels tens of miles from the Squaw Peak and Cave Creek Water Treatment Plants to the far ends of the distribution system. Free chlorine would dissipate before reaching those endpoints. Chloramine remains active.

Chloramine also produces lower levels of certain regulated disinfection byproducts. Free chlorine reacting with organic matter in source water generates trihalomethanes and HAA5 at higher concentrations than chloramine. Switching to chloramine is partly a compliance strategy, trading one set of byproducts for another. The byproducts of chloramine disinfection, including N-nitrosodimethylamine (NDMA), are different from chlorine byproducts and are also subject to monitoring.

Is chloramine in shower water harmful?

The EPA considers chloramine at municipal disinfection levels safe for drinking and bathing. Phoenix Water Services has operated a chloramine residual system within EPA parameters for years. The legal compliance answer is that chloramine in Phoenix water is not considered harmful at current levels.

The picture is more complex for specific populations. Fish and reptile owners know that chloramine cannot be removed by letting tap water sit overnight, as you can with free chlorine. It must be neutralized chemically before use in aquariums or reptile water. People on home dialysis must have a dechlorination system approved for chloramine removal, as chloramine passes through dialysis membranes and causes hemolytic anemia if not removed. For these uses, chloramine is a clinical concern, not just an aesthetic one.

For the general population, respiratory sensitivity is the most commonly reported concern. Inhaling steam from a hot chloramine shower is different from drinking water with chloramine in it. The bioavailability of inhaled volatile compounds differs from ingested compounds. Research on chloramine inhalation exposure in residential showers is ongoing and not fully resolved. If you or a household member has asthma, chronic respiratory conditions, or reports symptoms improving after travel and worsening at home, speak with your physician before drawing conclusions about chloramine.

Why does my Phoenix shower smell like a swimming pool?

The swimming pool smell in a Phoenix shower is chloramine volatilizing from hot water into the steam. Hot water releases dissolved gases more readily than cold water, and a small enclosed shower stall concentrates the vapor. The smell is particularly noticeable in newer or high-efficiency showers with large rainfall heads or body sprays that maximize hot water contact area. The warmer the water and the smaller the bathroom ventilation, the more concentrated the vapor gets.

The smell is real, not imagined, and not a sign that your utility is doing something wrong. It is the normal behavior of chloramine at residential temperatures. Homeowners who have lived in non-chloramine cities or who use filtered water when traveling and notice a significant difference are comparing chloramine water to water without it. The comparison is accurate.

What filter removes chloramine from shower water?

Catalytic carbon is the correct media for chloramine removal. Standard granular activated carbon (GAC), the media in most pitcher filters and refrigerator filters, has a slow reaction rate with chloramine and is not effective in the contact times available in point-of-use filters. Catalytic carbon has a modified surface structure that dramatically accelerates the chloramine reduction reaction. A whole-home system with a catalytic carbon block installed on the main supply line before the water heater removes chloramine at every tap and shower in the house.

Shower head filters that use vitamin C cartridges do neutralize chloramine effectively at the contact point. The limitation is cartridge life, typically 10,000 to 20,000 gallons, which in a typical Phoenix shower represents two to four months of use per cartridge. The ongoing cartridge cost adds up, and the filter only covers that one shower. A whole-home catalytic carbon system costs more upfront but covers every water outlet at a lower long-term cost per gallon of treated water.

Does a whole-home filter remove chloramine in Phoenix?

Yes, when the system uses catalytic carbon rather than standard activated carbon. The systems we install use a catalytic carbon block that is sized to the household peak flow rate, typically 10 to 15 GPM for a three bath home. Sizing matters. A undersized carbon block at high flow does not provide enough contact time for effective chloramine reduction. The catalytic carbon block also handles chlorine, taste, odor, and reduces trihalomethanes and HAA5 at every tap.

The carbon block has a service life measured in gallons, typically 100,000 to 150,000 gallons for a household-sized block. In a three to four person Phoenix household using 150 to 200 gallons per day, that is approximately 1.5 to 2.5 years per block. Our service plan includes block replacement on schedule so the filter is never depleted without your knowledge. A depleted carbon block passes unfiltered water without warning, because exhausted carbon passes water quietly.

What about chloramine and skin, hair, and laundry?

Phoenix homeowners frequently report dry and tight skin after showering, and a portion of that is chloramine stripping the skin's natural oil barrier in addition to the hardness-related dryness from mineral deposits. Laundry washed in chloramine water can experience faster fabric degradation compared to laundry washed in carbon-filtered water, particularly for delicate fabrics and athletic wear with technical coatings. Hair color treatments are affected by chloramine as well, and Phoenix hair stylists commonly advise color-treated clients to filter shower water to extend color longevity.