Red dye will measure water quality in Stillaguamish

  • Wed Aug 8th, 2012 8:09pm
  • News

By Gale Fiege Herald Writer

ARLINGTON — The Stilly will briefly run red next week.

A state Department of Ecology research team plans to put red dye in the Stillaguamish River on Wednesday evening as part of a water quality study.

The research team is scheduled to pour the fluorescent dye into the river about 8 p.m. at Haller Park in Arlington. The dye should dissipate quickly, but fluorometers are to be located in five places downstream from the park.

The instruments will measure the concentration of the dye in the water over a 12-hour period and help researchers measure river travel times and the rate at which a pollutant would dissipate in the river water, Ecology officials said.

“Research has shown the dye doesn’t affect humans, fish or wildlife health in any way at the very low concentrations we use, and we commonly use it for this type of scientific study,” said Mark Von Prause in a statement from the department. Prause is a scientist with Ecology’s environmental assessment program.

The Stillaguamish River water has a shortage of dissolved oxygen, something fish need to survive, Prause said. Too much nutrient pollution, such as from phosphorus and nitrogen, leads to less dissolved oxygen in the water.

The research will help Ecology’s Water Quality Program update a 2007 water-quality improvement plan that guides efforts to control sources of nutrient pollutants in the Stillaguamish watershed. For more information, go to