Monitoring Programmes for Bathing Waters Within the Frame of the EU Bathing Water Directive: The Experience of Catalonia

Abstract

The quality of coastal recreational waters is monitored in Europe and other geographical areas through the analysis of faecal indicator bacteria, i.e. total and faecal coliforms and more recently E. coli and intestinal enterococci as in the new EU Bathing Water Directive (2006/7/EC). The old and new indicators and their methods of analysis are presented in this chapter underlying the limitations detected for the methods included in the new Directive. The expertise achieved along the ca. 25 years of monitoring the Catalan bathing waters revealed the two factors responsible of sporadically altering the otherwise excellent water quality of our beaches. These factors are rain events and incidences of the sewerage system. The Catalan beaches have been classified on the basis of the impact that rain events may have on altering their water quality. This information is now used to provide almost real-time warnings through the recently launched mobile app. Common alteration of the water aspect such as water discolouration, phytoplankton blooms and presence of foam that may be perceived as contamination by the public showed after investigation to correspond mainly to natural phenomena. The interrelationship established with the municipalities and the developed communication systems enabled to obtain accurate timely information from each bathing area.