I found this on an "odd news" site, but no URL. Sorry:

Norwegian Composer Makes Music From Oslo's Sewers

A Norwegian composer is making music using noises recorded at a sewage treatment plant in Oslo. The city's 280,000 residents will generate noises in the plant every time they take a shower or flush a toilet.

Arne Nordheim has attached leads to a computer and plans to air the recorded sounds on 32 strategically placed loudspeakers below ground. Aftenposten quotes Mr Nordheim telling Dagens NÊringsliv newspaper that he has
studied the audio workings of the plant.

He says there is a clear distinction between the level of activity before and after the main evening news.

Anyone wanting to hear the music will have to visit the Bekkelaget plant because the avante-garde artist is not planning to release a CD.