Runoff from Road Surfaces - How Contaminated Is It?

From an urban water management perspective, roads are impervious surfaces which are directly connected to the stormwater drainage system and, consequently, are surfaces which respond quickly to storm events. As a result, roads are an important component of stormwater runoff quantity and quality management. To provide information for the necessary management of urban stormwater quality, a number of monitoring studies have been undertaken in the Sydney region. These studies have provided information regarding the quantity of pollutant constituents during both dry and wet periods and enabled the development of models for the prediction of the temporal distribution of the pollutant load from road surfaces. Presented in this paper will be the results of these monitoring programs. Also presented will be some guidelines for estimating the trace metal load likely to be transported from road surfaces during storm events.