Evaluation of equivalence between different methods for enumeration of fecal indicator bacteria before and after adoption of the new Bathing Water Directive and risk assessment of pollution

Abstract

The quality of bathing water is of considerable public importance due to the possibility of fecal contamination. In 2009, Croatia implemented the new European Bathing Water Directive (BWD, 2006/7/EC) establishing stricter microbiological standards for new parameters with new reference methods. This study aims to evaluate the equivalence of different methods according to the old and revised BWD and to provide the possibility of data comparison. Furthermore, the directive requires the establishment of the bathing water profile (BWP) for pollution risk assessment. The estimation of consistency of pollution risk assessment with obtained microbiological results was also performed. Six marine beaches of the Municipality of Rijeka (Croatia) were examined during the 2009 season. Statistical analysis showed equivalence between determination methods for fecal contamination indicators. Based on the current water classification results, the need for correction of estimated pollution risks and recommendations for inclusion of historical microbiological data during BWP enactment was noticed.

Keywords: Bathing Water Directive; Bathing water profile; Fecal indicator bacteria; Method equivalence; Pollution risk assessment; Recreational water.