March 25, 2015

The Bull Run Watershed provides Portlanders with some of the best drinking water in the world.  Because it’s so high in quality, we only have to minimally treat our water to make it safe to drink. 

The Portland Water Bureau treats our water through a process called chloramination. Chlorine is lightly added at the source to protect us from possible harmful bacteria and micro-organisms. Ammonia is then added to ensure the disinfection remains stable throughout the system as it travels to our homes and businesses. 

The bureau tracks our water quality carefully, and adjusts chlorine levels as needed. The bureau will sometimes adjust levels during the warmer months of spring and summer, as warm temperatures could cause chlorine to decrease more rapidly (like evaporation).

Some people are sensitive to changes in chlorine levels. If your water smells like chlorine, you can minimize it by putting water in the refrigerator overnight, adding a slice of lemon or cucumber, or by boiling it. 

Visit the Water Bureau’s website to learn more about water quality, or call the Water Quality Line at (503) 823-7525.