Environment Agency (formerly National Rivers Authority) v Empress Car Co (Abertillery) Ltd

For the offence of causing polluting matter to enter controlled waters, the prosecution must identify something the defendant did. The activity need not be the immediate or sole cause. Maintaining a tank, lagoon, sewage system or other operation may suffice.

Causation asks whether the defendant caused the pollution, not whether another person or event also caused it. Liability under section 85(1) of the Water Resources Act 1991 is strict but not absolute. An intervening act or natural event which is an ordinary fact of life does not break the causal connection, even if its precise occurrence was unforeseeable. An extraordinary event may do so. Whether an intervention is ordinary or extraordinary is a question of fact and degree.

Environment Agency (formerly National Rivers Authority) v Empress Car Co (Abertillery) Ltd concerned diesel oil which escaped from the appellant company's tank and entered the River Ebbw Fach. The tank's outlet was connected to a drum outside its protective bund. An unlocked tap was opened by an unidentified person, after which the drum overflowed and the oil passed through the yard drainage system into the river.

The Tredegar justices convicted the company under section 85(1) of the Water Resources Act 1991. The Crown Court dismissed its appeal, finding that the way in which the company maintained the tank caused the escape even if third-party interference was a major cause. The Divisional Court dismissed a further appeal by case stated.

The central issues were whether causing pollution required a positive act by the company and whether an unidentified person's opening of the tap prevented the company from having caused the oil to enter the controlled waters.

1. Disposition. The House unanimously dismissed the appeal. Lord Hoffmann delivered the leading speech. Lords Browne-Wilkinson, Lloyd of Berwick and Nolan expressly adopted his reasons. Lord Clyde delivered a separate concurring speech and reached the same result.

2. Activity rather than mere non-prevention. Per Lord Hoffmann, the distinction in section 85(1) of the Water Resources Act 1991 between causing and knowingly permitting pollution means that liability for causing must be founded on something the defendant did. This does not require an act which immediately released the pollutant. Maintaining a tank, lagoon, sewage system or other continuing operation is capable of being the relevant activity. The contrary approach in Price v Cromack [1975] 1 WLR 988 and Wychavon District Council v National Rivers Authority [1993] 1 WLR 125 was too restrictive.

3. The correct causal question. Per Lord Hoffmann, a court must ask whether the defendant caused the pollution. It should not ask which single person or event was the cause. The existence of another sufficient or concurrent cause is compatible with the defendant also having caused the pollution. Causation must be assessed in light of the purpose and scope of the statutory rule.

4. Intervening acts and events. The offence imposes strict, but not absolute, liability in the interests of protecting controlled waters. Reasonable foreseeability is not the criterion. Where escape also depended upon a third party's act or a natural event, the tribunal should decide whether that intervention was an ordinary fact of life or was abnormal and extraordinary. An ordinary intervention does not negative the causal effect of the defendant's activity, even if its precise form was unforeseeable. An extraordinary intervention may do so. The distinction is one of fact and degree.

5. Earlier authorities and application. Lord Hoffmann held that Impress (Worcester) Ltd v Rees [1971] 2 All ER 357 was wrongly decided and that the defendant in National Rivers Authority v Wright Engineering Co Ltd [1994] 4 All ER 281 should also have been convicted. On the facts, maintaining the diesel tank with an unlocked outlet, an ineffective containment arrangement and a direct drainage route to the river supplied ample evidence of causation. Lord Clyde likewise considered that managing an inadequate system could constitute an active operation. He agreed that the unidentified intervention was not so unusual as to supersede the company's activity as a causative factor.

1. House of Lords: In Environment Agency (formerly National Rivers Authority) v Empress Car Co (Abertillery) Ltd [1998] UKHL 5, reported at [1999] 2 AC 22, the House unanimously dismissed the company's appeal and left the conviction standing.
2. Divisional Court: Dismissed the company's appeal by case stated from the Crown Court and certified a question of general public importance concerning causation under section 85(1) of the Water Resources Act 1991.
3. Crown Court at Newport: Dismissed the company's appeal from the justices. It found that the manner in which the company maintained the tank caused the escape, even if third-party interference was a major cause.
4. Tredegar justices: Convicted the company of causing polluting matter to enter controlled waters.