Salem dumps 22 million gallons of raw sewage in the Willamette
The city of Salem released more than 22 million gallons of diluted raw sewage into the Willamette River on Thanksgiving afternoon and the following morning after heavy rain overwhelmed its sewer system.
That's enough to fill 33 Olympic-size swimming pools.
The release was permitted under state environmental regulations, said Nitin Joshi, the city’s environmental and regulatory affairs manager.
That’s because the 24-hour rainfall level passed a legal threshold, of 2.61 inches, at 6:45 a.m. Friday.
“Once it hits that anywhere throughout the system, that allows them to approve the city’s bypasses or overflows,” Joshi said.
That applies even if the release began before the threshold was reached, he said.
City officials allowed raw sewage to enter the river at Union Street from 11:15 p.m. Thursday through 1:43 p.m. Friday, releasing 19.6 million gallons.
They opened the gates at the North River Road diversion structure from 4:15 a.m. Friday through 6:10 a.m. Friday, releasing 2.65 million gallons.
When the ground becomes saturated, groundwater enters the sanitary sewer from cracks and holes in the pipes, footing drains and other sources from private property, city spokesman Mike Gotterba said.
“When this occurs the ability of the sewer system to transport sewerage to the water pollution control facility is exceeded,” he said.
The release was necessary to keep sewage from backing up and flooding streets and basements, Gotterba said.
That's exactly what happened in Southeast Salem Friday morning. At 8:45 a.m. public works officials responded to a complaint about raw sewage flowing from a manhole at 544 Idylwood Drive into Pringle Creek.
About 640 gallons of sewage was accidentally released to the creek, Gotterba said.
The releases were reported to the Oregon Department of Environmental Quality.
DEQ spokeswoman Katherine Benenati said the city reported it was operating an additional wet weather treatment facility, but it had pump failures from 2 a.m. to 4 a.m. Friday.
“At that point the wet weather treatment facility was taken offline and the city made the decision to release the raw sewage to the river to avoid a human health hazard that would have been created had it backed up into businesses and streets downtown during Black Friday shopping,” Benenati said.
The city has not determined the cause of the pump failure, she said.
City workers posted signs at both the Willamette River and Pringle Creek throughout the weekend warning the public to avoid the water, Joshi said. The signs were removed Monday after follow-up sampling showed normal bacteria levels.
The city also notified the city of Wilsonville, which takes its drinking water from the Willamette about 40 miles downstream.
Delora Kerber, Wilsonville’s public works director, said the sewage would not have impacted the city’s drinking water.
“By the time it gets to us it’s pretty diluted,” she said. “And we have state-of-the-art technology for water treatment. When it comes out after treatment it fully meets and exceeds the state’s requirements for drinking water.”
DEQ’s Western Region office received 11 additional reports of sewage overflows over the Thanksgiving weekend, Benenati said.
They came from systems in Dallas, Dayton, McMinnville, Albany, Corvallis, Amity, Lincoln City, Toledo, Siletz, Coos Bay and Arch Cape.
tloew@statesmanjournal.com, 503-399-6779 or follow at Twitter.com/Tracy_Loew
DEQ fines McMenamins for wastewater discharge in creek