Water quality managers traditionally assess the illness risk associated with indicator bacteria in bathing waters by comparing an average concentration to a concentration standard, where the average may be determined from a frequency distribution of concentrations.
The United States EPA concentration standards are determined as the concentration which gives an acceptable illness rate according to a mathematical relation between the concentration and illness rate (concentration-response relation).
However, further use can be made of the frequency distribution and concentration-response relation.
This paper presents a method for combining the temporal concentration frequency distribution with a concentration-response relation to obtain the averaged illness rate (that is. the expected illness rate).
First the method is developed for the concentration frequency distribution at a single location.
The method is also extended for the case where the temporal concentration frequency distribution is known at a number of points throughout the area in the vicinity of the outfall. in which case spatial contours of averaged illness rate can be determined.
The methods are demonstrated for a site at the North Shore.
Mots-clés Pascal : Baignade, Zone côtière, Bactérie, Pollution, Contamination, Qualité eau, Evaluation, Risque, Homme, Rejet eau usée, Prise décision, Nouvelle Zélande, Océanie, Indicateur biologique
Mots-clés Pascal anglais : Bathing, Coastal zone, Bacteria, Pollution, Contamination, Water quality, Evaluation, Risk, Human, Waste water discharge, Decision making, New Zealand, Oceania, Biological indicator
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 98-0498497
Code Inist : 002B30A02A. Création : 19/02/1999.