Debate on Uncertainty in Estimating Bathing Water Quality

Estimating the bathing water quality along the shore near a planned sewage discharge requires data on the source strength of bacteria, the die-off of bacteria and the actual dilution of the sewage. Together these 3 factors give the actual concentration of bacteria on the interesting spots on the shore. Each of the 3 factors varies with time and can only be estimated roughly with significant uncertainty. The author wants to debate the necessity of accepting these uncertainties and accordingly taking the uncertainty into the modelling of the consequence of a particular discharge.