[Rp61973]

Waste oil should never be dumped in street gullies. Commonly two sewer systems exist - foul and surface water. Many street gullies are connected to the surface water system and these normally outfall to rivers and brooks.

Oil in rivers and brooks is so common, especially in parts of London. Once oil gets in a watercourse, it will kill any life in there stone dead. Luckily there are big fines for idiots who drop substances other than rainwater into gullies.