Tap water that tastes like a swimming pool
The smell is disinfectant, and in most of the DMV it is chloramine rather than plain chlorine. It is safe to drink at the levels used, but it is why your water tastes flat or chemical and why the fridge filter never seems to keep up.
Signs you have it
- A pool or bleach smell from the tap, strongest in spring
- Flat, chemical taste in water, coffee and tea
- Fridge filter or pitcher stops helping within weeks
- Cloudy ice cubes
- Pets refusing tap water
What causes it
Utilities add chlorine to kill bacteria in the pipes. Most DMV utilities bond it to ammonia to make chloramine, which lasts longer in the distribution system. Chloramine is much harder to filter than free chlorine because the molecule is more stable.
In the DMV specifically
Fairfax Water, Arlington, DC Water, Loudoun Water, Prince William Water and Virginia American Water all use chloramine year-round and switch to free chlorine for a few weeks each spring to flush the pipes, which is when the smell peaks. WSSC Water and Howard County use free chlorine.
What fixes it
Recommended
Catalytic carbon at the main line
Breaks the chlorine-ammonia bond and adsorbs the result. Treats every tap, shower and appliance.
Also useful
Reverse osmosis at the kitchen sink
Its carbon pre-filters remove chloramine, and the membrane removes the disinfection byproducts (THMs, haloacetic acids) that carbon alone leaves behind.
Also useful
Both together
Our $2,499 package does both: whole-home catalytic carbon plus under-sink RO.
What does not work
- Standard carbon fridge filters (rated for chlorine, not chloramine; exhausted quickly)
- Letting water sit overnight (works for free chlorine, not chloramine)
- Boiling (concentrates dissolved solids and does not remove chloramine efficiently)
Related questions
Why is the chlorine smell worse in March and April?
That is the annual free-chlorine flush. Utilities that normally use chloramine switch to stronger free chlorine for a few weeks to clean the distribution system.
Is chloramine dangerous?
Not at drinking-water levels for people. It must be removed for kidney dialysis, aquariums and homebrewing, and it is harder on rubber plumbing parts than chlorine.