The water tank with its own carpet

Yes.  A water tank with its own carpet ! Yes.  The water tank had its own carpet!!  I came across a water tank that instead of a proper cover, a carpet was placed over the tank.  Over many years the carpet had gradually slipped into the water and had dispersed. The contaminated water was being used by students in the student accommodation.  The tank was obviously immediately condemned for the safety of the students. Students are famous, or infamous, for …