Advances in Water Treatment and Enviromental Management

12 WATER TREATMENTIn general Directives of this nature have been brought into use within theUK through the Departmental Circular. The European Commission hasrecently indicated that, in their view, such a route for implementation isunacceptable, in that all Directives are binding upon member states, andmust be incorporated within their national legislation. In view of this, theDepartment of the Environment is currently issuing Regulations throughthe medium of the Water Act to enact Directives.This action in itself is highlighting problems relating to the implementation,in a formal way of such Directives. For example the NRA is currently indiscussion with the Department over implementation of the Directiveconcerning the abstraction of surface water for the production of drinkingwater. The majority of surface water supplies in the UK, arise from reservoirs.The classification scheme laid down by the Directive relates the degree oftreatment to the quality of water abstracted. In a typical lake wherestratification occurs as a natural process, the water at the surface will bedifferent to that in the bottom layers. It would not be possible to guaranteethat all parts of a particular lake, at all times, met the classification criteriaand indeed in the design of reservoir systems provision is normally made toabstract water from the most suitable level or site. The problem for the NRAis how to define the point of application in such a way as to achieve apractical means of monitoring and operating the Directive. It would bedifficult to be required to guarantee that all water in a particular lake wasof precisely the same quality all of the time.Whereas some of the Directives are straight forward and merely give rise toa workload for the NRA to accomplish, other Directives are less easy to dealwith. The Dangerous Substances Directive, for example is a Directive withconstantly changing analytical requirements. The transfer of substanceswhich are toxic, persistent, and non-biodegradable into what is known asList 1 has been accelerated in recent years, and the need to identify sourcesof such substances and provide the analytical capability to detect them atvery low concentrations in natural waters is a challenge to the NRA’s newlaboratory network.COASTAL WATERSSo far the paper has concerned itself with inland problems, but the NRAhas responsibilities for coastal waters also. Two EC Directives are of topicalinterest in this context—the Bathing Water Directive, and the proposedDirective relating to the Treatment of Municipal Waste Water. Both apply tocoastal and inland waters, but within the United Kingdom, no freshwaterbathing sites have yet been designated. Much of the interest in the applicationof the Bathing Water Directive to coastal waters centres on the levels of