SPU Dye Testing Alarms Thornton Creek Neighbors
01/25/01

Many residents along the lower portions of Thornton Creek saw the creek turn bright green last Tuesday morning. The creek's appearance caused many to believe antifreeze had been dumped into the creek prompting numerous calls to both Seattle Public Utilities and the state Department of Ecology.

Fortunately, the cause of the discoloration was not pollution, but a harmless dye used by SPU to trace water flow through the storm drainage system. The dye was placed in Little Brook Creek, a tributary of the north fork of Thornton Creek, near 35th avenue NE between NE 115th street and NE 120th street.

The results of this test were plainly visible all the way downstream to Matthews Beach where Thornton Creek empties into Lake Washington.

Although unconfirmed by SPU, the appearance of the creek indicated that dye had again been placed in Little Brook Creek early Thursday afternoon.