Quality characteristics of surface and sea waters in Greece in relation to European union legislation

Abstract

The paper summarises the results of a survey of the quality characteristics of 21 lakes, 24 rivers and 5 gulfs in Greece. The field data was collected by the Ministries of Agriculture and Environment & Public Works and covers the period 1989-1992. Data processing and evaluation, in order to determine the degree of pollution and the sensitivity of the water bodies, was conducted by considering the relevant European Union (EU) legislation. The quality characteristics of 90% of the surface waters do not violate the mandatory limits of the Directives 75/440 and 80/440. However, a significant number of lakes (about 60%) are meso-eutrophic or eutrophic with nitrogen being the limiting nutrient. The main sources of nitrogen in these cases are related to agricultural practices and the measures specified in Directive 91/676 (closer monitoring, improvement of agricultural practices) should be implemented. Furthermore, the discharge of treated sewage should be avoided or in any case the degree of treatment should include nutrients removal, in accordance with the requirements of the Directive 91/271 for sensitive recipients. The evaluation of the quality characteristics of the examined gulfs was performed taking into consideration the classification proposed by the Directive 91/271, which is based on the degree of sensitivity of the water bodies with respect to eutrophication.