State to dye Pilchuck River pink to test water quality

GRANITE FALLS, Wash. -- Pilchuck River in Snohomish County may run pink or rust-colored Tuesday as researchers test water quality using a non-toxic dye.

Scientists with the Ecology Department plan to release the dye at two locations on the river at dusk Tuesday. They'll track the dye as it moves downstream.

The agency says the dye doesn't harm people, plants or fish.

Stretches of Pilchuck River are currently too warm and doesn't have enough oxygen, making it harmful to fish and other aquatic life. The river currently doesn't meet certain clean-water standards. It flows from the Cascade Mountains east of Granite Falls to Snohomish before joining the Snohomish River.

Researchers will collect river water samples over four days and gather data on temperature, dissolved oxygen and nutrients.

The information will ultimately guide the department and others in their cleanup plans.