A Sewage Problem for the Paris Olympics

The opening ceremonies for the Paris Olympics will not be held in a stadium, but outside on the banks of the river Seine. Many of the water sports will also be held in the river. The problem is that the river is often little more than a sewer, and has been as long as anyone knows. You can't old international sports events in polluted water, so Paris has worked for years to upgrade their sewage system for better water quality, but current samples still have unsafe levels of bacteria. So what are they going to do about it? Paris is taking the short-term tactic of making the water safe sometimes, specifically during the games, while also planning for long-range mitigation. Vox takes a look at the problem ahead of the Olympics and what the city is doing about it. This video has a skippable ad from 3:04 to 3:40.