Earlier this week Marconia asked Questionland why Seattle's water tastes like chlorine and smarty-pants Adam came through with the answer:
Federal law requires all cities in the U.S. to treat drinking water with chlorine. All cities, everywhere.
In fact, it isn't just that water must be treated - it must be delivered with detectable chlorine levels all the way to your tap. Chlorine breaks down and reacts in the delivery pipes, so excess must be added at the beginning of a line to make sure there is still some left at the end of the line.
Cities don't generally go beyond the detectablility standard (for health and financial reasons) so the "detectable" level at the last house on the line is usually detectable only in a laboratory - not by human taste buds. The end result? If you live near a chlorination point, your chlorine level may be unpleasantly high. If you live at the far end of the line, though, your water probably will have no chlorine taste.
I never knew that! Adam's answer is this week's Answer of the Week and now both Marconia and Adam will get a $25 gift card for Paliacci Pizza. Congrats!