Pollutant build-up and wash-off from selected land uses within a port environment : An insight into stormwater quality improvement

The Port of Brisbane Corporation is developing a world-class port facility at the mouth of the Brisbane River in Queensland. Located adjacent to the Moreton Bay Marine Park and within Australia's fastest growing region, the need to ensure appropriate stormwater management practices are in place is integral to our business. The unique nature of port operations, traffic types and storage modes, mean that stormwater quality parameters used for typical urban land uses may not be valid. To develop an in-depth understanding of the pollutant loads within our stormwater run-off, an investigation was undertaken into pollutant build-up and wash-off. Rainfall events typical to the region were replicated using a specially designed rainfall simulator over a number of port-specific land uses, and the pollutant build-up and wash-off samples were analysed for a wide range of parameters. Pollutant build-up and wash-off were found to be either lower or comparable to typical urban land uses such as residential, commercial or industrial. It was also found that most pollutants were not in dissolved form but rather bound to sediments in the 0.75-75pm size range. The study outcomes confirmed that water-quality improvement strategies targeting the removal of suspended solids as a surrogate approach to removing pollutants may be valid. However, the use of stereotypical designs may not always prove adequate in port areas as they may not be capable of removing sediments in the 0.75-75μm size range.