In Wychavon District Council v National Rivers Authority (Queen's Bench Division, Local Authority Law, 30 September 1992), the local authority operated and maintained sewers on behalf of the sewerage undertaker, Severn Trent Water.
In March 1990, raw sewage was seen to be flowing from an overflow into the river Avon at Evesham, apparently because of a blocked sewer. An NRA pollution control officer investigated the incident in the early Sunday evening of 11 March and informed the Council. Later that evening she returned, took statutory samples and again informed the Council, but no steps were apparently taken to prevent the discharge. It was not until the next day that the blockage was cleared by the Council.
The Council was charged under section 107 of the Water Act 1989 - now replaced by section 85(3) of the Water Resources Act 1991 - with causing the unauthorised discharge of sewage effluent. It was accepted that there were no inherent defects in the design and construction of the sewer, and the blockage had probably been caused by solid material entering it from a nearby hospital.
At a hearing before magistrates, the Council argued that while it was under a contractual duty to maintain the system, it had not performed any positive act which amounted to "causing" the discharge. The magistrates disagreed, and convicted the Council. By failing to have in place effective maintenance arrangements, the Council, they felt, had caused the discharge.
Causation is a somewhat metaphysical concept. Previous case law on the meaning of the term in water pollution cases - in particular the well known 1972 decision of the House of Lords in Alphacell v Woodward - implied that it involved some positive step on the part of the defendant.
In the present case, the Divisional Court was not prepared to depart from that general principle, and quashed the conviction. According to Lord Justice Watkins, "there is nothing to point to the performance by the Council of either a positive or deliberate act as such as could properly be said to have brought about the flow of sewage effluent into the river Avon."
The statute also makes it an offence knowingly to permit a discharge, and while this requires some actual knowledge of the circumstances on the part of the defendant, the concept of "permitting" is much wider and clearly does not necessarily involve positive physical action. The Court indicated that there were facts in the case which could have amounted to knowingly permitting the discharge in question, but the Council had not been charged with that offence and the matter could not be taken further.
More worrying, perhaps, for statutory sewerage undertakers were the Court's observations on the so-called deeming provisions of the legislation. Under section 87 of the 1991 Act, a statutory undertaker is deemed to have caused a discharge of sewage effluent where the discharge is from a sewer or works vested in the undertaker, and where the undertaker was obliged to receive the discharge into the sewer or works.
This deeming provision applies where the undertaker did not actually cause or knowingly permit the discharge, and, although various defences are built in, the Divisional Court noted that the policy behind the section implied that Parliament considered the undertaker to be best placed to accept responsibility for the discharge and thus the commission of the offence.
The Court held that although the Council was acting as an agent for the sewerage undertaker, it was not an undertaker as such, and was therefore not caught by the deeming provision. It seemed to the Court that the provision would have applied to Severn Trent Water, but since it had not been prosecuted the Court did not examine whether it could have been convicted. Where similar incidents occur in the future, however, the NRA may now more readily consider taking proceedings against statutory undertakers.