Alphacell Ltd v Woodward

A person causes polluting matter to enter a stream where, applying ordinary commonsense, that result is attributable to the person’s deliberate operation or chain of operations. The prosecution need not prove an intention to pollute, knowledge of the discharge or negligence.

The separate requirement that a person must knowingly permit pollution does not qualify the offence of causing it. A mechanical failure within an operation remains attributable to its operator unless an independent event, such as sufficiently powerful third-party intervention or an act of God, properly displaces that responsibility.

The appellants operated paper-manufacturing works beside the River Irwell. Polluted washing water entered settling tanks and was ordinarily pumped back into the works. If the pumps failed to control the water level, an overflow channel carried the effluent directly into the river. Both pumps became obstructed by vegetable matter, and polluted water overflowed into the river.

The magistrates convicted the appellants under section 2(1)(a) of the Rivers (Prevention of Pollution) Act 1951. The case was treated as containing no finding of negligence or knowledge. A majority of the Divisional Court dismissed the appeal, while Bridge J dissented.

The certified question was whether the offence of causing polluting matter to enter a stream could be committed without knowledge of the discharge and without negligence.

1. Disposition. The House unanimously dismissed the appeal. The appellants had caused the polluted water to enter the river within section 2(1)(a) of the Rivers (Prevention of Pollution) Act 1951, although the case was treated as involving neither knowledge nor negligence.
2. Meaning of “causes”. Lord Wilberforce held that causation must receive a commonsense meaning, without refinements such as causa causans, effective cause or novus actus. The appellants deliberately conducted the complete operation: they brought water into the works, polluted it, conveyed it to a tank connected directly to the stream and relied on pumps to prevent the inevitable overflow. A defect in the pumping stage did not prevent the operation from causing the pollution.
3. Viscount Dilhorne similarly reasoned that the intentional operation of the works, together with the system installed, brought the polluted liquid to the river. A person who intentionally performs acts producing a result may cause that result although it was unintended. Lord Pearson regarded the appellants’ positive activities as the governing explanation of the overflow. Lord Salmon likewise considered that causation was established by the active operation of plant designed and controlled by the appellants.
4. Knowledge and negligence. Lord Wilberforce held that “causes” and “knowingly permits” create distinct limbs. “Knowingly” cannot be read back into “causes”. Viscount Dilhorne, Lord Pearson and Lord Salmon agreed that the prosecution need not prove an intention to pollute, knowledge of the discharge or negligence. The statutory language and the public-interest character of the prohibition displaced any requirement of mens rea for causing pollution.
5. Independent events. Lord Wilberforce explained that third-party conduct does not invariably interrupt causation. The question is one of degree and the proper attribution of responsibility. Lord Cross considered that an operator who had started the relevant process could escape causal responsibility if another event, beyond its ability to foresee or control, brought about the overflow. No trespasser, act of God or extraordinary natural event was established here.

Order: appeal dismissed with costs.

1. House of Lords: The appeal was dismissed unanimously. The certified question was answered affirmatively, subject to proof that the accused caused or knowingly permitted the polluting matter to enter the stream.
2. Divisional Court of the Queen’s Bench Division: By a majority, Lord Parker CJ and Widgery LJ dismissed the appeal and upheld the conviction because the appellants’ activities caused the pollution. Bridge J dissented, considering knowledge or means of knowledge necessary.
3. Magistrates: The appellants were convicted under section 2(1)(a) of the Rivers (Prevention of Pollution) Act 1951 and fined £20.