Dirty River

As I've mentioned previously, the Tiber River has been pretty dirty since it flooded last week. At the drop in the river near the island bridge trash collects fairly significantly. It's clean sometimes and packed with plastic bottles stuck in the current at other times. Who cleans out the trash? This weekend I saw a huge metal box or cabinet-like thing trapped by the water in the dam and fighting furiously to escape but the river kept it in place. Obviously the current is keeping the trash collected there, so I am starting to think someone cleans it out. Does Rome hire people to fish the litter out of the river? Romans seems to take a lot of pride in their city and if they really have someone that cleans it out like they clean the sidewalks, I find that a very admirable trait of Rome.