In Italy this sort of thing is usually run by and/or blamed on the mafia. It's scary to think that the UK can do this to itself without needing the mafia involved.
The water companies were privatized under Thatcher, for those missing the context.
Note that the waste dumping problems are not all caused by water privatization, either. But as with the comparison to criminals, that's often conflated when people talk about it.
The reality is that it's not solely the water companies, even though if you put it to them many people would leap on the comparison to the Mafia.