Approaches adopted by the European Union and selected Member States for the control of urban pollution

Abstract

Several EU Directives have been adopted which have an influence on the control of urban pollution in particular the EU Urban Wastewater Treatment and the Integrated Pollution Control and Prevention Directive. In addition, the recently adopted Water Framework Directive (WFD) will have an additional impact on the control of urban pollution in particular related to storm overflows. The present paper provides a brief discussion of the EU legislation relevant to the control of urban pollution with special emphasis on the Urban Wastewater Treatment Directive (UWWTD) and its implementation in the Member States.

The recently adopted WFD requires the achievement of good ecological and chemical status in all waters. The implementation of the UWWTD by the Member States, which should be achieved by 2005, will make a significant contribution towards achieving good ecological and chemical status. However, besides the discharge of sewage effluents, storm overflows can have a significant impact on the quality of surface waters and they will therefore require adequate control in order to achieve the final goal of good ecological and chemical status. The paper, therefore, also provides a brief analysis of the permitting requirements in the different countries and of the criteria currently applied by the EU Member States for the design of combined sewer overflow systems. Not all countries currently require a permit for storm overflows and the design criteria for combined sewer overflows are generally based on the spill frequency or treatment capacity in terms of dry weather flow, which do not take into account the effect on the receiving water. However, in the UK a method has been developed to assess the impact of combined sewer overflows on the quality of the receiving water, which is being applied to ensure the design of the storm overflow is adequate for the protection of the receiving water. Member States will need to adapt their methodologies used for the design of storm overflow to ensure the requirements of the WFD, the achievement of good ecological and chemical water quality, is being met.