Untreated sewage released into river.

Byline: Joe Harwood The Register-Guard

The 2.43 inches of rain that fell on an already-saturated Eugene-Springfield from 4 p.m. Monday to 4 p.m. Tuesday overloaded the area's sewage treatment system and forced operators to release a million or more gallons of untreated sewage into the Willamette River, officials said Tuesday.

Officials at the Metropolitan Wastewater Management Commission said health risks from the raw discharges are minimal, but they suggested that the public curtail recreational outings on the river.

Other cities that released sewage into waterways Tuesday include Brownsville, Sweet Home, Salem, Toledo, Bandon, Port Orford, Gold Beach and Reedsport, said Jonathan Gasik, a senior engineer for the state Department of Environmental Quality, which regulates water pollution.

During heavy rains, stormwater lines that collect runoff from streets can overflow into nearby sanitary sewer lines. Also, floodwaters seep into sanitary sewage lines through manholes and cracks in lines. The net effect: The volume of wastewater flowing into sewage pump stations and treatment plants soars.

Dave Breitenstein, manager of the Metropolitan Wastewater Management Commission treatment plant in north Eugene, estimated the total release at 1 million to 5 million gallons. "It's probably toward the low end of that," he said.

The untreated sewage was released at two locations: the Filmore Pump Station near Maurie Jacobs Park and the Willakenzie Pump Station near Goodpasture Lakes Loop, said Rachael Chilton, a spokeswoman for the wastewater agency.

Breitenstein said neither pump station is equipped with discharge meters, so the estimates are rough.

Peter Ruffier, director of Eugene's Wastewater Division, said there are two choices when water flow exceeds the pumps' capacity: send it to the river or let it back up into streets and basements.

Breitenstein said the Filmore station, on the west bank of the river, opened its gates about 9:15 a.m. Tuesday, followed by the Willakenzie station, on the east bank, 45 minutes later. An attempt to close the gates at the Filmore facility Tuesday afternoon caused sewage to back up and overflow out of a manhole, he said, so the gates were reopened.

The sewage treatment plant can handle 175 million gallons a day of wastewater, enough to put down- town Eugene under a foot of water. When flow exceeds 200 million gallons, it gets diverted to the river, said Al Peroutka, an engineer and assistant manager at the commission.

Tuesday morning, "we were up around 225 million gallons," Peroutka said.

Such releases aren't uncommon in Western Oregon. The last time a release from the Eugene plant exceeded 1 million gallons was in 1997. The plant serves Eugene and Springfield.

The commission is planning upgrades in the next five years to prevent such discharges. The work will be funded through fees on new development. The $15 million first phase goes to bid next week, Peroutka said.

Under state and federal pollution control guidelines, cities that have to discharge sewage into waterways during extreme winter weather generally do not face fines.

Under a state law set to take effect in 2010, cities will not be allowed to release untreated sewage. Peroutka said the commission plans to have its facilities upgraded by that time so they can handle 277 million gallons a day.