Chloramine vs chlorine: why your Houston water smells different now

Two different disinfectants

Free chlorine and chloramine both disinfect drinking water, but they behave very differently once they are in the pipe. Free chlorine is aggressive and dissipates quickly — leave a pitcher on the counter overnight and much of it is gone. Chloramine is chlorine bonded with ammonia. It is more stable, holds its residual much further out into the distribution system, and does not simply air off.

Why utilities in this region use it

Greater Houston has been steadily converting from groundwater to treated surface water under regional water authority mandates, driven by subsidence regulation. Surface water travels further and needs a residual that survives the trip. Chloramine does that job better than free chlorine, and it produces fewer regulated disinfection byproducts. From a utility engineering standpoint it is the right call.

Why your filter stopped working

Carbon removes chloramine far more slowly than it removes free chlorine. A pitcher filter or a faucet-mount unit moves water past a small carbon bed too fast to do much. This is why homeowners in Cypress, Spring and Katy so often tell us their filter “used to work.” It did — on chlorine. The water changed underneath it.

What actually removes it

Contact time. A whole-home carbon bed with enough granular activated carbon gives the water the dwell time it needs, and a multi-stage reverse osmosis system handles it at the drinking tap. If chloramine taste is your complaint, carbon volume is the specification that matters, not brand name.