'There are many creatures in Angmar that carry venom or poisonous blood in their veins. But even so, how could all the water be affected so? Could something have spawned in the bowels of Carn Dum? Something monstrous and poisonous to all life?
'You must travel upstream to discover the source of the corruption. To Urugarth you must go and find evidence of such a creature. It would have to be a large beast, such are the amounts of poison in the water.
'The waters flow from Carn Dum's sewers down a waterfall into Urugarth. Perhaps you will find something of note where the waters run fastest?'
Fimreg studied the properties of the water you collected and believes that the source is tainted by something beyond mere machines of industry.
Search Urugarth for the creature poisoning the water
Urugarth is to the west of Gath Forthnír and north of Imlad Balchorth.
Fimreg believes that a large creature of some kind is poisoning the waters. If such a beast exists, proof of it will be found upstream in Urugarth.