Portland’s billion-dollar “Big Pipe” to keep sewage out of the Willamette River is working better than expected, according to a report presented Wednesday at City Council.
Portland’s system of combined sewer and stormwater used to dump raw sewage into the Willamette 100 days a year – even after moderate rain storms. After 20 years of work, and $1.4 billion in spending, Portland cut those sewage overflows in its test year of 2012.
The goal was to go from 100 a year to seven.
The head of Portland’s Bureau of Environmental Services, Dean Marriott, says last year was rainier than usual, but the system still overflowed fewer than seven times.
“We only had to do it on four, so we actually did better than what we were required to do,” Marriott says. “People have asked me, ‘Well, why did you have to do it on four occasions?’”
Marriott says the system will likely overflow a few times a year, to avoid overwhelming the system.
State and federal officials told city leaders they were pleased with how the system is doing.