TRACING SEWAGE-CONTAMINATED SEDIMENTS IN HAMILTON-HARBOR USING SELECTED GEOCHEMICAL INDICATORS

Natural tracers in bottom sediments around the outfall of the Burlingt on Skyway Sewage Treatment Plant (STP) were analyzed to investigate th e pathways of fine contaminated sediments associated with the outfall. The properties examined were: coprostanol and isotope ratios of nitro gen and carbon. The spatial distribution pattern for all the tracers w as characterized by extreme values in the vicinity of the outfall, wit h a systematic decrease with distance. The STP outfall is clearly the source for coprostanol as well as for light N-15 and heavy C-13. Th, d istribution pattern for coprostanol and delta(15)N showed the most con sistent transport patterns, while delta(13)C patterns were different a nd might be contaminated by terrestrial carbon from sources other than the STP. Interpretation of the net transport patterns from coprostano l and delta(15)N indicates a primary transport trend southward, with a secondary trend northward, curving westward. The net transport patter ns inferred from the tracer indicators are compatible with models of t wo-dimensional circulation of a buoyant effluent plume, under the effe ct of the prevailing wind-driven current regime.