There are problems about settling whether only the type of harm or the specific harm must be unforeseeable, and the moment at which foreseeability is to be judged.
The decision in Cambridge Water Co made an immediate change to the law, for the first time requiring foreseeability of harm to be considered in cases brought under Rylands v Fletcher and the general tort of nuisance.
Secondly, it was the first decision to state that Rylands may be a sub-set of nuisance, and as such applied the same requirement of foreseeability of harm to nuisance, where previously such a requirement had not existed.
Based on the original decision in Rylands, Goff argued that it had always been intended for foreseeability of harm to be a factor, something not previously put into law by the English judiciary.
Kennedy also chose to consider foreseeability of harm a factor in cases brought under Rylands, and stated the fact that harm was not foreseeable was a factor in his decision.
"We need to increase transparency on physical markets to give foreseeability.
The Council stated that "It could not be right to discriminate between different cases of nuisance so as to make foreseeability a necessary element in determining damages in those cases where it is a necessary element in determining liability, but not in others".
But foreseeability, though it bears some relation to probability, is clearly a non-causal criterion, and one that can apply only to human conduct, not to other alleged causes.
He then stated that Rylands was arguably a sub-set of nuisance, not an independent tort, and as such the factors which led him to including a test of foreseeability of harm in Rylands cases also imposed such a test on all nuisance cases.
"I am floored that they have restricted it in this way with respect to the advanced state of irreversible decline and reasonable foreseeability of death".
"The foreseeability of self-harm was something that every one of the people in the chain of supervision and the command of the prison service should have been aware of".
