Litter and discarded refuse.
Large rock fragments left by a melting glacier etc.
Rubble, wreckage, scattered remains of something destroyed.
The ruins of a broken-down structure.
That which sullies or defiles.
Silt or sediment deposited from flowing water.
The scoria on the surface of molten metal in the ladle.
The liquid discharges from kitchens, washbasins, toilets etc; sewage.