Proceedings - Teaching and Learning Centre - Simon Fraser ...

Fraser River Action Plan 3rd Research Workshop
Survey of Contaminants in
Suspended Sediment and Water in the Fraser River Basin
M. Sekela, R. Brewer, C. Baldazzi, G. Moyle and T. Tuominen
Environment Canada
Abstract
Concentrations of trace organic contaminants (dioxins, furans, chlorophenolics, polycyclic aromatic
hydrocarbons, polychlorinated biphenyls, pesticides, fatty acids and resin acids) were measured in suspended
sediments and/or water samples collected upstream and downstream of six pulp mills located in the Fraser River
basin. Sampling was conducted under fall low-flow conditions over three consecutive years (1992 - 1994) and
under winter base-flow conditions in February 1993. Concentrations of contaminants in both sediment and water
were used to calculate log Koc values for dioxins, furans, chlorophenolics and polycyclic aromatic hydrocarbons.
Results indicated that:
1. dioxins, furans, chlorophenolics, polycyclic aromatic hydrocarbons, fatty acids and resin acids,
measured in suspended sediments, were found in higher concentrations downstream of pulp and paper
mills than at reference sites upstream of the mills;
2. these contaminants were generally found in higher concentrations during winter base-flow periods than
under fall low-flow conditions;
3. concentrations of 2,3,7,8-T4CDD and 2,3,7,8-T4CDF in suspended sediments have decreased from
levels measured in 1990 prior to implementation of pulp mill abatement measures;
4. phase partitioning of polycyclic aromatic hydrocarbons between sediment and water was highly variable
and appeared to be influenced by site-specific environmental conditions; and,
5. none of the organic contaminants exceeded existing federal guidelines or provincial water quality
criteria for the protection of aquatic life. However, guidelines or criteria currently do not exist for many
organic contaminants which were measured at elevated levels downstream of the mills.
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