Specific organic components as tracers of contaminated fine sediment dispersal in Lake Ontario near Toronto

Organic contaminants were monitored in bottom sediments around the outfall of the Humber sewage treatment works on Humber bay, Ontario lake. These included sewage-related compounds such as the faecal sterol coprostanol, alpha-tocopheryl acetate, and linear-chain n-alkane hydrocarbons, considered to be good natural markers exhibiting clear dispersal plumes from a point source, and yielding transport pathway indicators for contaminated sediments. Net transport patterns of these markers showed a primary trend toward the south and south-west with a secondary trend northward. Sewage outfall materials were clearly differentiated from those coming from river and open lake.