Seeing yellow or green-tinted tap water? Here’s why

Organic materials sometimes tint the water in streams and reservoirs, much like tea leaves.

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A little color in the water isn’t always a cause for concern.

Photo via city of Portland

Tap water is generally supposed to be colorless, except when the forest near Mount Hood decides to remind us where our drinking water comes from.

The city of Portland recently announced that some residents might be seeing light yellow or greenish-colored water pouring from their taps. We know the conclusion your mind immediately jumped to and no, a family of entrepreneurial yetis is not making “lemonade” snowcones and letting their leftovers melt into the Bull Run Watershed.

Heavy rainfall from an atmospheric river earlier this month is the real culprit. City officials said a yellow or green tint is produced by tannins in organic matter that washes into the streams and reservoirs in the watershed. Since drinking water from Bull Run is not filtered, the color makes its way to homes and businesses.

Officials said the tannins affecting the water’s appearance are harmless and will likely clear up within days. Water that looks more like coffee should be reported to the city’s Water Quality Line.

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