London is a very, very old city. Some street drains lead to watercourses that go to the countryside. Section 33 of the Environmental Protection Act 1990 makes it an offence to deposit or dispose of waste in a way likely to pollute land or water. This can include pouring liquids into street drains that lead to watercourses.
The fine (£150) is the standard fixed penalty in that borough (with the possibility to reduce if paid quickly) for such an infringement
She’s a Turkish citizen and probably didn’t know the rules.
The fact the fine was withdrawn suggests even the authorities felt it may not have been the best use of enforcement resources.
“Section 33 of the Environmental Protection Act 1990 makes it an offence to deposit or dispose of waste in a way likely to pollute land or water.”
This is classic anarcho tyranny at work. Many western nations have the same issue.
https://chroniclesmagazine.org/view/anarcho-tyranny-u-s-a/