The cost of treating the sewage flowing into it was not something it was either relevant or proper for the Environment Secretary to consider in determining at what point water ceased to be a river and became instead the sea.
Mr Justice Harrison granted two applications for judicial review of the Secretary of State's decisions, on 18 May 1994, when establishing the outer estuarine limits of the Humber and Severn estuaries and designating "high natural dispersion areas" within those estuaries, for the purposes of the Urban Waste Water Treatment (England and Wales) Regulations 1994 (SI 2841), which implemented in the UK the provisions of the EC Urban Waste Water Directive 91/271 (OJ 1991 135/40). The respective applications were brought by Kingston upon Hull City Council and by Bristol City Council and Woodspring District Council.
Genevra Caws QC, Philip Sands and Jonathan Marks (P.M. Barker, Kingston upon Hull; D. Lewis, Bristol; and T. Simpkin, Weston-super-Mare) for the applicants; Nigel Pleming QC (Treasury Solicitor) for the Secretary of State.
Mr Justice Harrison said the point in issue related to the degree of treatment, primary or secondary, that should be required for urban waste water, including household and industrial sewage, discharged by the two estuaries. The Directive and Regulations required secondary treatment, which was more stringent and expensive, as the norm. Establishment of the outer estuarine limits and indentification of directly affected the question whether primary or secondary treatment was required.
An "estuary" was defined in article 2 of the Directive as the "transitional area at the mouth of a river between fresh water and coastal waters," and "coastal waters" as those "outside the low-water line or the outer limit of an estuary."
Secondary treatment was required under the Directive for all discharges into estuaries from "agglomerations", or concentrations of population and economic activity, above a "population equivalent" or PE level of 10,000. All the relevant discharges within the applicants' jurisdictions were from agglomerations of more than 10,000PE. In such areas, primary treatment was only permissible in respect of discharges into high natural dispersion areas within coastal, as opposed to estuarine, waters.
The Secretary of State designated the Humber Bridge and the Severn Road Bridge as the outer estuarine limits of the respective rivers, and the waters of the Humber estuary and of Avonmouth/Portishead and Kingston Seymour in the Severn estuary as high natural dispersion areas.
The applicants contended that this would allow waste water discharged into the Humber and Severn estuaries beyond the designated limits to be subjected to primary treatment only, on the basis that it was being discharged into high natural dispersion areas within coastal waters. They argued that in fixing estuarine limits objective criteria such as water salinity and topographical features should be used.
The Secretary of State submitted there was nothing wrong in using the man-made topographical features of bridges to define the limits, and that he was permitted in his discretion to establish the limits in such a way as to avoid extra cost where there would be no adverse environmental effect.
Article 2 did not specify any criteria to be applied when establishing an outer estuarine limit. If it had intended salinity or topography to be used, it could have said so. Member states had a discretion. But there had to be a genuine and rational assessment in each case of what actually constitutes the estuary having regard to the characteristics of the area of water in question and the purpose of the Directive.
The cost of treating waste water was not a consideration relevant to that exercise. An area of water either was or was not an estuary regardless of what it would cost to treat waste water discharged into it.
The cost-based approach vitiated the decisions in these cases and they should be quashed.
Paul Magrath, Barrister