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Session 1997-98
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Judgments - Empress Car Company (Abertillery) Ltd. v. National Rivers Authority


  Lord Browne-Wilkinson   Lord Lloyd of Berwick   Lord Nolan
  Lord Hoffmann   Lord Clyde







My Lords,

      I have had the advantage of reading in draft the speech prepared by my noble and learned friend, Lord Hoffmann. For the reasons he gives I would dismiss the appeal.


My Lords,

      I have had the advantage of reading in draft the speech prepared by my noble and learned friend, Lord Hoffmann. For the reasons he gives I too would dismiss this appeal.


My Lords,

      I have had the advantage of reading a draft of the speech of my noble and learned friend Lord Hoffmann. For the reasons he has given, I too would dismiss this appeal.


My Lords,

      Empress Car Company (Abertillery) Ltd. ("the company") was convicted at the Crown Court sitting at Newport, Gwent (His Honour Judge Crowther Q.C. and two justices) of "causing poisonous, noxious or polluting matter or sold waste to enter controlled waters" contrary to section 85(1) of the Water Resources Act 1991. "Controlled waters" are defined in section 104(1)(c) and (3) to include any river and in this case were the waters of the River Ebbw Fach, which ran close by the company's premises in Abertillery. A large quantity of diesel oil had escaped from a tank into the river in circumstances which I shall shortly describe. Section 85(1) reads as follows:

     "A person contravenes this section if he causes or knowingly permits any poisonous, noxious or polluting matter or any solid waste matter to enter any controlled waters."

      The company was originally convicted by the Tredegar justices and appealed to the Crown Court. Its appeal from the Crown Court to the Divisional Court by way of case stated was also dismissed. It now appeals to your Lordships' House. The facts as found in the case stated may be summarised as follows. The company maintained a diesel tank in a yard which was drained directly into the river. The tank was surrounded by a bund to contain spillage, but the company had overridden this protection by fixing an extension pipe to the outlet of the tank so as to connect it to a drum standing outside the bund. It appears to have been more convenient to draw oil from the drum than directly from the tank. The outlet from the tank was governed by a tap which had no lock. On 20 March 1995 the tap was opened by a person unknown and the entire contents of the tank ran into the drum, overflowed into the yard and passed down the drain into the river.

      The Crown Court found that there was a history of local opposition to the company's business. The tap might have been turned on by a malicious intruder, an aggrieved visitor or an upset local person. The incident coincided with a public inquiry about a disputed footpath which was to be held on the following day. But the court made no finding as to the identity of the person who turned on the tap. The evidence was consistent with it having been an employee or a stranger. The court held that it did not matter because on either view the company had "caused" the oil to enter the river. In the case stated, the court gave the following reasons:

     "8. . . . The appellant had brought the oil onto the site and put it in a tank with wholly inadequate arrangements for withdrawal--outside the bund. We had regard to the nature and position of the bund, the inability of the tap to be locked and the inadequacy of the bund to contain overflow in the circumstances which happened, whether they were deliberate or negligent or careless.
     "9. The appellant should have foreseen that interference with their plant and equipment was an ever-present possibility, and they failed to take the simple precaution of putting on a proper lock and a proper bund and this was a significant cause of the escape even if the major cause was third party interference."

The company's case before the Divisional Court was that if the evidence was consistent with the tap having been opened by a stranger, it should have been acquitted. The escape would have been caused by the stranger and not the company. The Divisional Court disagreed, saying that although it would be true to say that the escape had been caused by the stranger, it was open to the Crown Court to find that it had also been caused by the company. But they said that the authorities on the subject were not easy to reconcile and certified the following question of general public importance:

     "Whether a person can be convicted of an offence under section 85(1) of the Water Resources Act 1991 of causing polluting matter to enter controlled waters if it is proved that - 

        (a) he held the polluting matter and contained it in such a way as it would not escape but for a positive act by himself or another; and

        (b) he failed to take reasonable precautions to prevent such an escape occurring as a result of an action by a third party; and
     It is not proved that he took any other actions which resulted in the pollution."

      Before your Lordships, Mr. Philpott for the company repeated his submission that the cause of the escape was not the keeping of the oil by the company but the opening of the tap by the stranger. He also said that "causing" for the purposes of section 85(1) required some positive act and that the escape could not be said to have been caused by any such act by the company. All it had done was to create a state of affairs in which someone else could cause the oil to escape. There are accordingly two issues in the case. The first is whether there has to have been some "positive act" by the company and, if so, whether the company did such an act. The second is whether what it did "caused" the oil to enter the river.

1. Acts and omissions

      My Lords, the two limbs of section 2(1)(a) of the Rivers (Prevention of Pollution) Act 1951, which was in the same terms as section 85(1) of the 1991 Act, were analysed by Lord Wilberforce in Alphacell Ltd. v. Woodward [1972] A.C. 824, 834:

     "The subsection evidently contemplates two things--causing, which must involve some active operation or chain of operations involving as a result the pollution of the stream; knowingly permitting, which involves a failure to prevent the pollution, which failure, however, must be accompanied by knowledge."

      Putting the matter shortly, if the charge is "causing", the prosecution must prove that the pollution was caused by something which the defendant did, rather than merely failed to prevent. It is, however, very important to notice that this requirement is not because of anything inherent in the notion of "causing". It is because of the structure of the subsection which imposes liability under two separate heads: the first limb simply for doing something which causes the pollution and the second for knowingly failing to prevent the pollution. The notion of causing is present in both limbs: under the first limb, what the defendant did must have caused the pollution and under the second limb, his omission must have caused it. The distinction in section 85(1) between acts and omissions is entirely due to the fact that Parliament has added the requirement of knowledge when the cause of the pollution is an omission. Liability under the first limb, without proof of knowledge, therefore requires that the defendant must have done something.

      In this sense, Mr. Philpott is right in saying that there must have been some "positive act" by the company. But what counts as a positive act? We were referred to two cases in which the defendant's conduct had been held to be insufficient. In Price v. Cromack [1975] 1 W.L.R. 988 the defendant maintained two lagoons on his land into which, pursuant to an agreement, the owners of adjoining land discharged effluent. The lagoons developed leaks which allowed the effluent to escape into the river. Lord Widgery C.J. said that the escape had not been caused by anything which the defendant had done. There was no "positive act" on his part. The effluent came onto the land by gravity and found its way into the stream by gravity "with no act on his part whatever:" see p. 994. The other case is Wychavon District Council v. National Rivers Authority [1993] 1 W.L.R. 125. The council maintained the sewage system in its district as agent for the statutory authority, the Severn Trent Water Authority. It operated, maintained and repaired the sewers. As sewage authority, it received raw sewage into its sewers. On the occasion in question one of the sewers became blocked. The sewage flowed into the stormwater drainage system and into the River Avon. The Divisional Court held that the Council had not done any positive act which caused the pollution. If it had known of the blockage it might have been liable for "knowingly permitting" but it could not be liable for causing.

      My Lords, in my opinion these two cases take far too restrictive a view of the requirement that the defendant must have done something. They seem to require that his positive act should have been in some sense the immediate cause of the escape. But the Act contains no such requirement. It only requires a finding that something which the defendant did caused the pollution. I shall come later to the question of what amounts to causing. Assuming, for the moment, that there was a sufficient causal connection between the maintaining of the lagoons in Price v. Cromack or the operation of the sewage system in Wychavon District Council v. National Rivers Authority and the respective escapes, I do not see why the justices were not entitled to say that the pollution was caused by something which the defendants did. Maintaining lagoons of effluent or operating the municipal sewage system is doing something.

      In National Rivers Authority v. Yorkshire Water Services Ltd. [1995] 1 A.C. 444 the House was invited to say that the law had "taken a wrong turning" in the requirement of a "positive act" as formulated in Price v. Cromack and Wychavon District Council v. National Rivers Authority. Lord Mackay of Clashfern L.C., at p. 452, said that he regarded those cases as turning on their own facts but added that the word "cause" should be used in its ordinary sense and that "it is not right as a matter of law to add further requirements." In Attorney-General's Reference (No. 1 of 1994) [1995] 1 W.L.R. 599, 615 Lord Taylor of Gosforth C.J. in the Court of Appeal said, in my view rightly, that the insistence in Price v. Cromack and Wychavon District Council v. National Rivers Authority on a positive act as the immediate cause of the escape was a "further requirement" which should not have been added. The only question was whether something which the defendant had done, whether immediately or antecedently, had caused the pollution.

      In the present case, the Crown Court found that the escape was caused by the way the company maintained its tank of diesel fuel. Maintaining a tank of diesel is doing something and therefore, provided that it was open to the court to find the necessary causal connection established, they were in my view entitled to convict. It is to the notion of causing that I therefore now turn.

2. Causing

      The courts have repeatedly said that the notion of "causing" is one of common sense. So in Alphacell Ltd. v. Woodward [1972] A.C. 824, 847 Lord Salmon said:

     "what or who has caused a certain event to occur is essentially a practical question of fact which can best be answered by ordinary common sense rather than by abstract metaphysical theory."

      I doubt whether the use of abstract metaphysical theory has ever had much serious support and I certainly agree that the notion of causation should not be overcomplicated. Neither, however, should it be oversimplified. In the Alphacell case, at p. 834, Lord Wilberforce said in similar vein:

     "In my opinion, 'causing' here must be given a common sense meaning and I deprecate the introduction of refinements, such as causa causans, effective cause or novus actus. There may be difficulties where acts of third persons or natural forces are concerned . . ."

      The last concession was prudently made, because it is of course the causal significance of acts of third parties (as in this case) or natural forces that gives rise to almost all the problems about the notion of "causing" and drives judges to take refuge in metaphor or Latin. I therefore propose to concentrate upon the way common sense notions of causation treat the intervention of third parties or natural forces. The principles involved are not complicated or difficult to understand, but they do in my opinion call for some explanation. It is remarkable how many cases there are under this Act in which justices have attempted to apply common sense and found themselves reversed by the Divisional Court for error of law. More guidance is, I think, necessary.

      The first point to emphasise is that common sense answers to questions of causation will differ according to the purpose for which the question is asked. Questions of causation often arise for the purpose of attributing responsibility to someone, for example, so as to blame him for something which has happened or to make him guilty of an offence or liable in damages. In such cases, the answer will depend upon the rule by which responsibility is being attributed. Take, for example, the case of the man who forgets to take the radio out of his car and during the night someone breaks the quarterlight, enters the car and steals it. What caused the damage? If the thief is on trial, so that the question is whether he is criminally responsible, then obviously the answer is that he caused the damage. It is no answer for him to say that it was caused by the owner carelessly leaving the radio inside. On the other hand, the owner's wife, irritated at the third such occurrence in a year, might well say that it was his fault. In the context of an inquiry into the owner's blameworthiness under a non-legal, common sense duty to take reasonable care of one's own possessions, one would say that his carelessness caused the loss of the radio.

      Not only may there be different answers to questions about causation when attributing responsibility to different people under different rules (in the above example, criminal responsibility of the thief, common sense responsibility of the owner) but there may be different answers when attributing responsibility to different people under the same rule. In National Rivers Authority v. Yorkshire Water Services Ltd. [1995] 1 A.C. 444 the defendant was a sewerage undertaker. It received sewage, treated it in filter beds and discharged the treated liquid into the river. One night someone unlawfully discharged a solvent called iso-octanol into the sewer. It passed through the sewage works and entered the river. The question was whether the defendant had caused the consequent pollution. Lord Mackay of Clashfern L.C., with whom the other members of the House agreed, said, at p. 452:

     ". . . I am of opinion that Yorkshire Water Services having set up a system for gathering effluent into their sewers and thence into their sewerage works there to be treated, with an arrangement deliberately intended to carry the results of that treatment into controlled waters, the special circumstances surrounding the entry of iso-octanol into their sewers and works does not preclude the conclusion that Yorkshire Water Services caused the resulting poisonous, noxious and polluting matter to enter the controlled waters, notwithstanding that the constitution of the effluent so entering was affected by the presence of iso-octanol."

So in the context of attributing responsibility to Yorkshire Water Services under section 85(1) (then section 107(1)(a) of the Water Act 1989), it had caused the pollution. On the other hand, if the person who put the iso-octanol into the sewer had been prosecuted under the same subsection, it would undoubtedly have been held that he caused the pollution.

      What these examples show is that it is wrong and distracting, in the case of a prosecution under section 85(1), to ask "What caused the pollution?". There may be a number of correct answers to a question put in those terms. The only question which has to be asked for the purposes of section 85(1) is "Did the defendant cause the pollution?" The fact that for different purposes or even for the same purpose one could also say that someone or something else caused the pollution is not inconsistent with the defendant having caused it. The way Lord Wilberforce put it in Alphacell Ltd. v. Woodward [1972] A.C. 824, 835 was as follows:

     "rather than say that the actions of the appellants were a cause of the pollution I think it more accurate to say that the appellants caused the polluting matter to enter the stream."

      I turn next to the question of third parties and natural forces. In answering questions of causation for the purposes of holding someone responsible, both the law and common sense normally attach great significance to deliberate human acts and extraordinary natural events. A factory owner carelessly leaves a drum containing highly inflammable vapour in a place where it could easily be accidentally ignited. If a workman, thinking it is only an empty drum, throws in a cigarette butt and causes and explosion, one would have no difficulty in saying that the negligence of the owner caused the explosion. On the other hand, if the workman, knowing exactly what the drum contains, lights a match and ignites it, one would have equally little difficulty in saying that he had caused the explosion and that the carelessness of the owner had merely provided him with an occasion for what he did. One would probably say the same if the drum was struck by lightning. In both cases one would say that although the vapour-filled drum was a necessary condition for the explosion to happen, it was not caused by the owner's negligence. One might add by way of further explanation that the presence of an arsonist workman or lightning happening to strike at that time and place was a coincidence.

      On the other hand, there are cases in which the duty imposed by the rule is to take precautions to prevent loss being caused by third parties or natural events. One example has already been given; the common sense rule (not legally enforceable, but neglect of which may expose one to blame from one's wife) which requires one to remove the car radio at night. A legal example is the well-known case of Stansbie v. Troman [1948] 2 K.B. 48. A decorator working alone in a house went out to buy wallpaper and left the front door unlocked. He was held liable for the loss caused by a thief who entered while he was away. For the purpose of attributing liability to the thief (e.g. in a prosecution for theft) the loss was caused by his deliberate act and no one would have said that it was caused by the door being left open. But for the purpose of attributing liability to the decorator, the loss was caused by his negligence because his duty was to take reasonable care to guard against thieves entering.

      These examples show that one cannot give a common sense answer to a question of causation for the purpose of attributing responsibility under some rule without knowing the purpose and scope of the rule. Does the rule impose a duty which requires one to guard against, or makes one responsible for, the deliberate acts of third persons? If so, it will be correct to say, when loss is caused by the act of such a third person, that it was caused by the breach of duty. In Stansbie v. Troman [1948] 2 K.B. 48, 51-52, Tucker L.J. referred to a statement of Lord Sumner in Weld-Blundell v. Stephens [1920] A.C. 956, 986, in which he had said:

     "In general, even though A is in fault, he is not responsible for injury to C which B, a stranger to him, deliberately chooses to do. Though A may have given the occasion for B's mischievous activity, B then becomes a new and independent cause."

Tucker L.J. went on to comment: