Yellow, orange, reddish or brown water
This problem is sometimes seen first thing in the morning, or after periods of lower water use. It is also seen at seldom-used faucets. The water should clear after flushing the faucet briefly. The cause is most likely galvanized iron plumbing in the building. It does not indicate that the plumbing is about to fail or that it needs to be replaced, unless there is also a noticeable reduction in water pressure.
If this is only occurring with hot water, flushing the hot water tank may help by clearing out the sediment in the bottom of the tank. Hot water increases the rate of corrosion in plumbing. You may want to consult a plumber for safety precautions.
Sudden discolored water
If the discoloration is sudden, there may be some activity that has disturbed the direction or rate of flow in the City water main, such as use of a fire hydrant or a water main valve in your vicinity. Discolored water comes from internal pipe rust and sediment getting stirred up. When this happens the water is still safe. However, the water may be unappealing, so we recommend that you wait until it clears before drinking it.
The water should clear on its own. Try running the cold water for a few minutes to see if it is clearing or still discolored. If the water does not clear, let the water sit for an hour. Then run the water for a few minutes and flush the toilet a couple of times. If the water remains discolored, please contact Customer Service at (206) 684-3000. If your home is located on a dead-end line, it may take longer to clear up and our crews may come out to flush the pipe.
Avoid running hot water if the cold water is still discolored. This will minimize filling the hot water tank with turbid water. If you are washing clothes at the time, it is better to stop the cycle while it is full and wait until clean water is available to finish. If you allow the water to empty from the washing machine and go into the spin cycle it is more likely to cause permanent staining to the laundry items.