Council Directive 76/464/EEC of 4 May 1976 on pollution caused by certain dangerous substances discharged into the aquatic environment of the Community3 has been significantly amended on several occasions4. In order to clarify matters, a codification of the provisions in question should be drawn up.

There is a need for general and simultaneous action by the Member States to protect the aquatic environment of the Community from pollution, particularly that caused by certain persistent, toxic and bioaccumulable substances.

Several conventions are designed to protect international watercourses and the marine environment from pollution. It is important to ensure the coordinated implementation of these conventions.

Discrepancies between the provisions applicable in the various Member States with regard to the discharge of certain dangerous substances into the aquatic environment may give rise to unequal conditions of competition and thus have a direct influence on the functioning of the internal market.

Decision No 1600/2002/EC of the European Parliament and of the Council of 22 July 2002 laying down the Sixth Community Environment Action Programme5, provides for a number of measures to protect fresh water and sea water from certain pollutants.

In order to ensure effective protection of the aquatic environment of the Community, it is necessary to establish a first list, called List I, of certain individual substances selected mainly on the basis of their toxicity, persistence and bioaccumulation, with the exception of those which are biologically harmless or which are rapidly converted into substances which are biologically harmless, and a second list, called List II, containing substances which have a deleterious effect on the aquatic environment, which can, however, be confined to a given area and which depends on the characteristics and location of the water into which such substances are discharged. Any discharge of these substances should be subject to prior authorisation which specifies emission standards.

Pollution through the discharge of the various dangerous substances within List I must be eliminated. Limit values were fixed by the Directives referred to in Annex IX to Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 establishing a framework for Community action in the field of water policy6. Article 16 of Directive 2000/60/EC provides for the procedures for developing the control measures and environmental quality standards applicable to priority substances.

It is necessary to reduce water pollution caused by the substances within List II. To this end Member States should establish programmes which incorporate environmental quality standards for water, drawn up in compliance with Council Directives, where they exist. The emission standards applicable to such substances should be calculated in terms of these environmental quality standards.

It is appropriate for one or more Member States to be able, individually or jointly, to take measures more stringent than those provided for under this Directive.

An inventory of discharges of certain particularly dangerous substances into the aquatic environment of the Community should be drawn up in order to know where they originated.

It may be necessary to revise and, where required, supplement Lists I and II of Annex I on the basis of experience, if appropriate by transferring certain substances from List II to List I.

This Directive should be without prejudice to the obligations of the Member States relating to the time limits for transposition into national law of the Directives set out in Part B of Annex II,