WATER QUALITY OF STORMWATER RUNOFF FROM TEN INDUSTRIAL SITES

First flush runoff samples, collected during 4 storm events from 10 industrial sites, were analysed for trace metals, organic compounds, pesticides and conventional pollutants. First flush and composite samples were also obtained from 3 consecutive storms. Five industrial groups were represented: car salvage, vehicle maintenance, wood preservation, metal fabrication, scrap and recycling. Copper and zinc were found in all samples at concentrations of 5-21,400 ppb. Sediment deposition at the sampler directly affected the level of metals in the runoff sample. Several organic compounds and pesticides were detected but only dichloromethane was found at more than one site. Concentrations of conventional pollutants, such as BOD and nutrients, were more closely related to individual site maintenance than business activity, except for oil and grease. There were no significant differences in the compositions of 3-h composite samples at all the sites for these pollutants.