Chloramine in Drinking Water

If your tap water smells a little like a swimming pool but your utility says they don’t use chlorine — they’re probably using chloramine. It’s the disinfectant of choice for a growing number of water systems, and it’s a tougher customer than chlorine when it comes to filtration.

What it is. Chloramine (usually monochloramine) is made by combining chlorine with ammonia. Utilities have used it since the 1930s, and its use has grown because it lasts longer in the distribution system and forms fewer disinfection byproducts (like TTHMs and HAA5) than free chlorine. Over 68 million Americans drank chloraminated water as of the last big survey, and the number has only grown.

Where it comes from. Your utility, on purpose. If your annual water quality report lists a disinfectant residual and mentions chloramine — or your utility sent a notice about switching disinfectants — that’s your answer. This is a city-water topic.

The health picture, honestly. The EPA caps chloramine at 4.0 mg/L (measured as chlorine), and water meeting that standard is considered safe to drink, cook with, and bathe in. Above that level, eye and nose irritation, stomach discomfort, and anemia are the reported effects. Two groups must remove it completely: kidney dialysis patients (it must never enter the bloodstream) and aquarium owners (it’s lethal to fish). Everyone else — it’s a taste, smell, and peace-of-mind issue more than a health emergency.

How to test. Your utility’s report tells you whether they use chloramine and at what residual. Home test kits for total chlorine will pick it up. If your water smells like a pool but tests low for free chlorine, suspect chloramine.

What removes it. Here’s the key point: standard carbon is slow and incomplete against chloramine — you need catalytic carbon. Catalytic carbon breaks the chlorine-ammonia bond far more effectively than regular GAC. A whole-house catalytic carbon system is the standard answer. Reverse osmosis also removes it effectively at the drinking-water tap. UV is an established technology for chloramine removal in dialysis and pharmaceutical settings.

What does NOT remove it. Standard pitcher filters and fridge filters — they’re built for chlorine, not chloramine, and contact time is too short. Boiling doesn’t reliably remove it. Letting water sit out, which works for chlorine, barely dents chloramine — that’s exactly why utilities switched to it.

What I’d buy

Treatment type: a whole-house catalytic carbon system, NSF or WQA listed, at the point of entry. Not standard carbon — catalytic. That’s the difference between actually removing chloramine and just hoping. For drinking water only, an under-sink RO works.

Chloramine isn’t the villain some corners of the internet make it out to be — it’s a legitimate disinfectant with real benefits. But if you want it out of your water, you need the right carbon for the job. Regular carbon won’t cut it.

Curious what’s in your tap? Start with What’s In Your Water?