An independent analysis found a project that aims to reduce polluted water that spills in the Lake Washington Ship Canal is trending $30 million over budget, according to Seattle Public Utilities.
The cost estimate for the Ship Canal water quality project is now $570 million, which is more than the estimate approved by Seattle City Council last year in SPU's 2018-23 capital improvement budget.
SPU stressed in a Council briefing Tuesday morning that it does believe it will result in a rate increase.
The project, called the most complex in SPU history, is a part of agreements to keep the city and county in compliance with the U.S. Clean Water Act and state regulations. The 2.7-mile underground storage tunnel will prevent the release of 81 million of gallons of raw sewage and polluted runoff into the Ship Canal and Lake Union.
SPU says it has a 65 percent confidence that the project will not exceed the existing projection.
