State regulators have told the city of Corvallis the treated wastewater it returns to the Willamette River during the summer is too warm for endangered salmon and other fish. So the city is talking about a $14 million project to cool it.
City officials say it that would mean increases of several dollars a month for ratepayers.
The Corvallis Gazette-Times reports that the City Council plans to spend $700,000 to investigate the idea.
It would pipe treated wastewater to a golf course for irrigation and to an artificial wetland of up to 30 acres so the water can cool as it migrates through the subsurface.
The city's treatment plant is across the river from those sites, so the pipes would have to go beneath the bed of the Willamette.