Water Quality and the Discharge of Cooling Water into Rivers, Lakes and Coastal Waters

Abstract

This paper resumés some of the main findings and conclusions of a study group on cooling water problems (1) set up by UNIPEDE (2). The paper represents only the personal point of view of the author, in particular as chairman of the above mentioned group. The basic aim of the work was the study of the effects of the discharge of cooling water in the receiving water bodies (rivers, lakes and coastal waters). This type of assessment permits a more balanced and pragmatic approach to aspects such as thermal pollution, entrainment, impingement and pollution by antifouling agents. The first part of the paper deals with the problem of damage to organisms entering a cooling system. An important factor in assessing the meaning of such aspect is the growing evidence that there is no reduction in fish population of the receiving water body associated with the operation of modern power plants despite the catch in the once through-cooling systems due to entrainment and impingement, that can be minimized, but not avoided. The second part deals with the different methods of fouling prevention in power plants, with their possible environmental effects in the receiving water bodies. The third part is a comprehensive review of the results of aquatic impact studies at power plants, that is the results of many experimental investigations carried out in the field to evaluate the effects of the operation of once through cooling systems sited on rivers, lakes, or coastal waters.