Bottom sediment characteristics in stormwater ponds and wetlands in Calgary, Alberta

This paper presents the characteristics of metals and nutrients concentrations in bottom sediment from two wet ponds and two wetlands in Calgary, Alberta. Sediment cores were sampled at four to six locations along the flow path in each facility. In total, twenty-six core samples were taken from the four facilities. Each core was processed in the lab and sediment samples were extracted from different deposited layers. Seventy sediment samples were extracted from the cores and were analyzed for nutrients and metals concentrations. In general, pollutants concentrations of Fe and Zn are higher in the wet ponds than in the wetlands, but Mg, K, Ca, S and TN are higher in the wetlands than in the wet ponds. The values of Mn and P were fairly similar between the wet ponds and wetlands. Also, it was observed that in general, the pollutants concentrations decreased along the flow path and with depth of the sediment.