Stormwater quality in Lismore, NSW, a regional urban centre

Stormwater flow peaks from a discrete 480 hectare urban catchment in Lismore, Northern NSW, were sampled over a four month period, in order to determine pollutant concentrations. Samples were analysed for suspended solids, dissolved and particulate inorganic and organic forms of phosphorus and nitrogen, faecal indicator bacteria, oil, grease and heavy metals. Comparison of total nitrogen and phosphorus concentration ranges and averages from this study with results of metropolitan studies showed similar total phosphorus and lower total nitrogen concentrations in the present study than typical metropolitan concentrations. Concentrations of acid-extractable metals in stormwater sampled were also lower range. The lower total nitrogen and metals components may reflect lower atmospheric pollutant concentrations due to lower traffic densities and minimal industrial activity compared to many large cities.