Spatial Distribution and Characterization of Contaminated Soils in Riverbanks of Saint-François and Massawippi Rivers (Southern Québec)

Abstract

Des sols contaminés aux hydrocarbures (C10-C50) et d'autres contaminants ont été découverts récemment dans les berges des rivières Saint-François et Massawippi, entre les municipalités de Eustis et Drummondville (sud du Québec). Il est probable que cette contamination provienne d'un déversement accidentel ou illégal dont la source serait l'ancienne mine de Eustis située au abord de la rivière Massawippi. La couche contaminée se retrouve parfois à plus d'un mètre de profondeur des berges. Malgré qu'il existe de nombreux rapports gouvernementaux sur la qualité de l'eau de ce bassin, aucune étude sur la contamination des berges et des sédiments du lit n'a été réalisée le long des rivières Saint-François et Massawippi, même si ces rivières circulent à travers d'anciennes zones industrielles et minières. Cette étudie vise à évaluer la distribution spatiale de la contamination le long des berges et dresse une caractérisation du type et du niveau de concentration des hydrocarbures et autres contaminants (ex. métaux lourds). Les résultats obtenus indiquent que certaines berges sont davantage contaminées par des hydrocarbures (C10-C50), en particulier dans le secteur de Windsor. Les autres polluants (métaux lourds, BPC et HAP) indiques des faibles niveaux de contamination à l'exception de certains métaux (Cu et Zn). Pour les sites plus pollués, ils sont inclus dans les critère B et C qui présente certaines contraintes d'utilisation du sol en tenant compte des normes du Ministère du Développement durable, de l'Environnement et des Parcs.

Isotopic Record of Lead Contamination in Alluvial Soils and Tree Rings on Recent Floodplains (Southern Québec, Canada)

“…The gap is also very small (±0.006) for 1955, as values recorded for the same two specimens are 0.846 and 0.840 ( 206 Pb/ 207 Pb). Overall, the findings point to a consistency between 1955 and 1964, when contamination events were reported in regional newspapers that mentioned a pollution event in October 1955 (unknown source) and an oil spill in May 1963 on the Saint-François River (Saint-Laurent et al 2008a;St-Laurent et al 2009). …”

Hydrocarbons, Pb-Concentrations, and Pb-Isotope Ratios in Contaminated Alluvial Soils (Southern Québec, Canada)

“…Our previous work conducted on hydrocarbon-contamined layers found in alluvial soils (Saint-Laurent et al, 2008;2010a;2010b) showed marked differences in the Pb isotope values (e.g., 206 Pb/ 207 Pb, 208 Pb/ 206 Pb), suggesting separate spills of petroleum products in the rivers. For instance, the values obtained for Pb isotope ratios 206 Pb/ 207 Pb ranged from 0.124 to 0.175 ± 0.01 SD (Saint-Laurent et al, 2010b;2010c).…”

“…The mining sites at the Eustis-Capelton-Albert complex , located along the Massawippi River in south-central Québec, are an example of mining sites that have been abandoned, with untreated toxic waste having contaminated the water and aquatic organisms (Berryman et al, 2003). The former Eustis mine also served as a storage site for pulp and paper solid waste as well as for various discharges into the Massawippi River, including illegal discharges of oil which spread over more than 100 kilometers along the banks of the Massawippi and Saint-François rivers (Saint-Laurent et al, 2008;2010a). Traces of these spills, whether accidental or intentional, are easily visible in the soil of the riverbanks, especially in the Eustis, Capelton, Windsor, and Richmond sectors, forming dark-colored layers with varying thicknesses (2 to 90 cm) in soil profiles, and contain hydrocarbons, Pb, and other trace metal elements (Saint-Laurent et al, 2008;2010a).…”

“…The former Eustis mine also served as a storage site for pulp and paper solid waste as well as for various discharges into the Massawippi River, including illegal discharges of oil which spread over more than 100 kilometers along the banks of the Massawippi and Saint-François rivers (Saint-Laurent et al, 2008;2010a). Traces of these spills, whether accidental or intentional, are easily visible in the soil of the riverbanks, especially in the Eustis, Capelton, Windsor, and Richmond sectors, forming dark-colored layers with varying thicknesses (2 to 90 cm) in soil profiles, and contain hydrocarbons, Pb, and other trace metal elements (Saint-Laurent et al, 2008;2010a). These hydrocarbon-contaminated layers are usually found at more than one meter in depth in the riverbanks, and some trace metals contained in these contaminated layers (e.g., Pb and Zn) exceed the generic criteria for contaminated soils.…”

“…The objectives of the study are to supplement our previous work on the source of soil contamination and to identify the trace metals and the concentration and composition of hydrocarbon-contaminated layers found in the soils located along the Massawippi and Saint-François rivers in southern Québec (Saint-Laurent et al, 2008). More specifically, the focus is on hydrocarbon and Pb concentrations and stable Pb isotopic ratios ( 206 Pb/ 207 Pb, 208 Pb/ 206 Pb, 204 Pb/ 206 Pb) of the hydrocarbon-contaminated layers found in soils.…”