STORAGE OF SEDIMENTS AND ASSOCIATED METALS AND PHOSPHORUS IN BED SEDIMENTS OF AN URBAN RIVER

With the rapid growth of the number of people living in urban areas, there is increasing concern associated with the quantity and quality of sediment in urban rivers. In many cases, it is difficult to assemble information on sediment in urban rivers – many of which are relatively small – due to a lack of sediment monitoring programs in urban areas. Channel bed sediment represents a suitable way to assemble such information. This paper describes work conducted in a river within the city of Prince George, British Columbia, Canada, that aimed to determine the total mass of the sediment and associated contaminants (metals and phosphorus) stored in the channel bed sediment. We also determined if the sediment in this urban river was contaminated when compared to provincial and federal sediment quality guidelines. Samples of the fine sediment stored in the channel bed were collected at several sites along the length of the river and over a few years in order to determine spatial and temporal patterns of sediment and contaminant storage. Results suggest that the temporal and spatial patterns of sediment and contaminant storage reflect the spatial location of land use activities (e.g. agriculture and industry) in the contributing watershed. In the case of sediment-associated contaminants, the total mass of contaminants is relatively high and worthy of remediation action and improved urban planning.