Why is the Seine only 'kind of clean'?
Paris invested 1.5 billion dollars to clean up its river, but tests show that it is unsafe to swim after heavy rains. Does this mean that the money went down the drain - figuratively and literally? BBC senior journalist Petra Zivic interviewed Dan Angelescu, the founder of Fluidion, a company monitoring water quality in the French capital.
Video by Petra Zivic and Anna Bressanin, additional editing by Ellenoor Shameli, additional reporting by Roja Assadi and Marek Polaszewski