The Divisional Court dismissed an appeal by the authority by way of case stated by Warwickshire justices who had dismissed an information against Wright Engineering alleging an offence contrary to section 107(1)(a) of the Water Act 1989.
Wright Engineering stored heating oil in a tank near a surface water drain. The flow of oil into a sight gauge was controlled by a tap. Although there had been minor incidents of vandalism at the site, it had not been a serious problem and no lock was fitted to prevent the tap being vandalised. During the Christmas shutdown in 1990, the sight gauge was vandalised and Racecourse brook was polluted with oil.
The justices found that the discharge of oil was the result of an intervention by a third party and that the vandalism involved was not reasonably forseeable because it was out of all proportion to the earlier minor incidents.
Roger D H Smith QC (National Rivers Authority) for the authority; James Tillyard (G F Lodder & Sons) for Wright Engineering.
MR JUSTICE BUCKLEY said that foreseeability would be relevant to any inquiry into whether a party 'knowingly permitted' polluting matter into controlled waters, but of less significance in a consideration of 'causes'. Here the object of the tank was to retain oil and that object was defeated by vandals. The cases gave guidance but each would have its own factual peculiarities. Forseeability was one factor which a tribunal might consider in seeking to apply common sense to the question of who or what caused the result under consideration.
On the facts found, it was open to the justices to find that the vandals 'caused' the escape and not Wright Engineering. The fact of past vandalism on a smaller scale and of a different type was something which the justices clearly considered but understandably decided was insufficient to alter their view. The justices were entitled to acquit.
Lord Justice Simon Brown agreed.
Ying Hui Tan, Barrister