Since Britain has short fast rivers and is washed by a turbulent and tidal sea, there has been an obvious argument of economic self-interest for Britain not to accept emission standards for water set by reference to what is necessary to protect, say, the Rhine, which drains many industrial areas and which is used as an important source of drinking water by Germans and Dutch. Since many of Britain’s most polluting industries have chosen to locate on estuaries and drinking water is abstracted upstream, it can plausibly be argued that to set emission standards as stringent as those needed for a river that is to be used for drinking water is to fly in the face of the economic principle of comparative advantage: Britain for pollution purposes, it can be argued, is well favoured by geography just as for transport purposes or, more facetiously, for the purposes of growing lemons, it is disadvantaged by geography. Since Italian lemon growers take advantage of the sun that geography brings them, and grow lemons rather than engage in some other activity for that very reason, and since German industrialists benefit from proximity to continental markets as a result of geography, so also it is argued that Britain should quite properly profit from the ability to locate industries on estuaries or on the coast where acute pollution problems are less likely to arise and where the sea water can assimilate or destroy the pollutants.

Where toxic substances are persistent and bioaccumulable the arguments for allowing less than the best discharge abatement technology are harder to sustain and it is over these substances that the dispute has centred. Not least of the difficulties has been agreeing which are the truly persistent toxic substances.

The opposing arguments for emission limit values and for quality objectives that came to a head with Directive 76/464 have had the effect of forcing Member States into camps, with Britain often alone in one. But it would be a mistake to suppose that the two approaches are totally incompatible and that Britain and the other Member States have pursued one to the exclusion of the other. In Britain, as in other countries, policy has not always been singleminded and elements of both approaches have been used for both water and air pollution. In developing national positions for the purposes of the debate in the Community there has been a tendency – not entirely excusable, it must be said – to play down the elements that do not fit the negotiating position adopted so that a distorted picture emerges. Nationalism, even of a benign kind, and regard for the facts have never been easy bedfellows.

The need to derive the benefits of both approaches became increasingly accepted both in Britain and elsewhere, and featured in the fourth action programme on the environment. The British government announced a change of policy at the Conference on the North Sea held in London in 1987 and accepted that the discharge to water of the most dangerous substances should be subject to controls based on best technology. This was then embodied in the Environmental Protection Act 1990.