SALEM, Ore. -- Nearly 57 million gallons of diluted raw sewage flowed into the Willamette River and area streams after heavy rains overwhelmed Salem’s sewage treatment system Sunday.
That’s more than twice the amount released during a similar event on Thanksgiving 2016.
The city chooses to release sewage into the Willamette to prevent it from backing up and flooding streets and basements, city spokesman Mike Gotterba said.
The releases are permitted under state environmental regulations when at least 2.61 inches of rain fall over 24 hours, which was the case during storms this week and in November.
City officials allowed raw sewage to enter the Willamette River at Union Street from 5:18 a.m. Sunday until 6:40 p.m. Monday, releasing a total of 56,690,000 gallons, Gotterba said.
In addition to the authorized release, city officials also discovered raw sewage flowing from at least nine manholes across the city, beginning early Sunday morning and ending Tuesday.
As a result, officials estimate that 173,700 gallons of sewage flowed into Pringle Creek; 67,780 gallons flowed into Clark Creek; 26,655 gallons flowed into Claggett Creek; 10,350 gallons flowed into Waln Creek; and 8,100 gallons flowed into the Little Pudding River.
The grand total: 56,976,585 gallons.
The city posted signs on all the water bodies warning people to avoid contact with the water because of potentially high bacteria. The signs will remain up until follow-up sampling shows normal bacteria levels