Comparison of methods to estimate suspended solids loads in urban stormwater

Abstract

[Abstract]: Planning of stormwater management strategies often requires estimating the concentration or mass load of pollutants in storm runoff generated from urban areas. In Australia, it is common practice to use simple methods that adopt a constant event mean concentration (EMC) for all storms under analysis. Alternatively, a stochastic concentration may be used to introduce variability between storm events. A comparison is made between three of these 'Mean EMC Methods' and five proposed methods. Each method was evaluated in terms of accuracy in predicting suspended solids EMCs against data measured for a road surface located in Toowoomba, Queensland. The cumulative error in estimating the total load for a sequence of storm events was also assessed. The Mean EMC Methods demonstrated low accuracies compared to the proposed alternatives.