What easily could have been a run-of-the-mill sewer pipeline replacement project in Oregon went from underground to underwater—creating what participants say will be the world’s first buoyant gravity line. Photo: Brown And Caldwell Pipeline under construction in Lake Oswego, Ore., will be the world’s first buoyant-gravity line when completed next April. Now under construction, the Lake Oswego interceptor sewer boasts 17,000 ft of wastewater-carrying pipe and another 12,000 ft of attached air-filled buoyant pipe. Replacing an existing submerged concrete pile-supported pipeline built in 1963, the new system will hook to the city’s current system on both sides of the lake.
The 2016 Summer Olympics boating and swimming events have put an international spotlight on what has been a long-running problem in Rio de Janeiro—untreated sewage and trash are clogging up major bays and waterways.