CORVALLIS, Ore. (AP) Corvallis residents might get a small surprise next week: Traces of pink dye floating down the Willamette River.
Not to worry, says the city: This is only a test.
The Corvallis Gazette-Times reports the traces of pink dye could be visible in the river up to one half-mile downstream beginning on Monday.
It's being used to study the city's wastewater treatment plant as a requirement of the city's state-mandated pollution discharge permit.
The dye is not toxic, but any contact with it could result in staining of clothes or skin.
The "concentrated dyestuffs" are also used for tracing the infiltration of waste water into soil from industrial sources.