Developments in water quality standards and classification schemes in England and Wales

Abstract

This paper discusses the changes in national water quality classification schemes in England and Wales that have been proposed following the introduction of new legislation. The conclusion has been reached that two separate systems are necessary. A new General Quality Assessment scheme has been introduced for the purpose of assessing and reporting upon status and trends in water quality. A separate system of Use Classifications will be progressively introduced to drive the water quality planning process through the setting of Water Quality Objectives on a statutory basis. Recent advances in ecotoxicology have provided the opportunity for the development of new, more ecologically relevant, approaches to deriving water quality standards. One example of this is the development of criteria relevant to rivers affected by intermittent pollution for which alternative ways of expressing standards have been proposed and applied in conjunction with dynamic impact modelling techniques.