Comparisons of the characterization of sediment from four stormwater ponds in Ontario

Contaminated sediment has been singled out as a major environmental problem by the Ministry of the Environment, Ontario. Many previous studies have evaluated the level of contaminants captured in storm water and found that sludge/sediments from the ponds contained concentrations of contaminant that exceeded the “Lowest Effects Level” (LEL) of the Guidelines for the Protection and Management of Aquatic Sediment in Ontario. In this study, it was mainly to evaluate the characteristics of the quality of the storm water sediment in different types of neighbourhood. Neutron Activation Analysis (NAA) instead of the Inductively Coupled Plasma (ICP) conducted the analysis of the composition of sediment. The Neutron Activation Analysis (NAA) facility in McMaster Nuclear Reactor is an extremely sensitive multi-element analysis technique with great accuracy and precision. . It is a non-destructive analysis that allows determination of many elements simultaneously at trace level in samples. Four different storm water ponds around city of Burlington, Ontario, Canada were sampled of summer, 2005. Two of the storm water ponds are located in the town of Flamborough, Ontario, Canada. The remaining two ponds are located beside Dartnall Road and Ancaster soccer field. The first two ponds are located in residential area, Darnall road is located in highway/commercial area and the last pond is located in commercial/light industry area. The particle size distribution of Parkside road site, Waterdown road site and Dartnell road site were69?m, 45?m and 20?m with another peak concentration around 831?m, 1258?m and 831?m size particles respectively. The sludge particle size distribution for Ancastor soccer field storm water pond had a maximum concentration at 20?m. The particle shapes were irregular. Thirty-one elements were found in the sediment and nine among these thirty-two elements were below detection limit by NAA. Seven elements were detected with a concentration higher than 1000 ppm, six elements had a concentration between 1000ppm and 100ppm, and the remaining ten elements had a concentration lower than 100ppm. The main compositions (above 1000ppm) of the dried sludge included Al > Ca > Fe > K > Mg > Na > Ti. The trace compositions (below 1000ppm) included Mn > Cl > Ba > Sr > Zn > Cr > V > La > Nd > As > Co > Sc > Br > Sm > Th > Eu. Four regulated elements were detected by NAA. The concentration of Cr, Fe and Zn in Parkside Road site were higher than the LEL level; The concentration of Cr, Fe Zn and As in Waterdown road site were higher than the LEL level; The concentration of Cr and As in Dartnall site were higher than the LEL level; The concentration of Fe, Zn and As in Ancaster soccer field site were than the LEL level and the concentration of Cr in that area was higher than SEL level. The significant of the sediment pollution might be further evaluated.