If your water smells like a pool every spring, or a filter that worked on your old house does nothing here, chloramine is the likely reason. Here is what it is and what removes it.
Updated
Quick answer
Chloramine is chlorine combined with ammonia. Raleigh and other NC utilities use it because it lasts longer in the pipes, and that same stability is why boiling, letting water sit and basic pitcher filters do little. A whole-house catalytic carbon filter, sized to your home's flow so the water gets enough contact time, removes it at every tap.
Chloramine is chlorine with ammonia added. Utilities use it because it lasts longer in miles of pipe than plain chlorine and forms fewer of the regulated disinfection byproducts. Raleigh uses it; the city's 2025 water report lists ammonia added at both treatment plants to form chloramines.
The trade-off is that the same stability makes it harder to get out of your water at home.
| Chlorine | Chloramine | |
|---|---|---|
| How long it lasts in pipes | Fades faster | Lasts longer |
| Let a pitcher sit overnight | Mostly gone | Still there |
| Boiling | Removes it | Removes little in normal boiling |
| Standard carbon filter | Removes it well | Needs more contact time |
| Catalytic carbon | Removes it | Built for it |
| Fish tanks, dialysis | Must be removed | Must be removed, with a product rated for chloramine |
Systems that use chloramine switch to straight chlorine for a few weeks each year to clean the pipes. In Raleigh it runs roughly late February through early April. During the switch the water smells and tastes more like a pool, and people who never noticed their water suddenly do.
If the smell bothers you only in spring, your utility is on chloramine the rest of the year.
Catalytic carbon is made to break chloramine down, and a whole-house tank gives the water the contact time it needs. Showers, laundry and cooking water all get it.
Drinking waterAn RO system's carbon stages and membrane together give clean drinking water at the kitchen sink, and also remove PFAS and lead.
Vitamin C shower filters reduce chloramine in one shower. They do nothing for the rest of the house.
Small carbon cartridges have too little contact time for chloramine. Fine for taste, not a fix.
Yes. The City of Raleigh adds ammonia to chlorine to form chloramine at both of its treatment plants, and switches to straight chlorine for a few weeks each spring.
It is regulated by EPA and used by many large U.S. utilities. The main complaints are taste, smell and skin dryness. It must be removed for fish tanks and kidney dialysis.
No. Chlorine fades from an open pitcher overnight; chloramine mostly stays. That is why tricks that worked on chlorinated water stop working.
A whole-house catalytic carbon filter, sized for your home's flow so the water gets enough contact time. Ours is built for chlorine and chloramine.
Check your utility's annual water quality report, or ask us during a free in-home water test.
A free in-home test confirms it, and a whole-home carbon system takes care of it.