INTRODUCTION The European Union Water Framework Directive, defines pollution as: "... the direct or indirect introduction, as a result of human activity, of substances or heat into the water or land which may be harmful to human health or the quality of aquatic ecosystems or terrestrial ecosystems directly depending on aquatic ecosystems, which result in damage to material property, or which impair or interfere with amenities and other legitimate uses of the environment." . The gradual but si...
