The diesel spillage entered the River Dochart near Killin on Friday [BBC] A diesel spillage into the River Dochart which flowed into the River Tay in Perthshire appears to be clearing, the environment watchdog has said. During a visual inspection, the Scottish Environment Protection Agency (Sepa) said the east end of Loch Tay was clear and no impacts could be seen in the River Tay, from Kenmore to Aberfeldy.