IS THE HYDE-PARK DUMP, NEAR THE NIAGARA RIVER, STILL AFFECTING THE SEDIMENT OF LAKE-ONTARIO

Fifteen dated sediment cores from the four Lake Ontario sedimentation basins were analyzed by electron capture, gas chromatographic mass spe ctrometry for three fluorinated compounds originating from the Hyde Pa rk Dump near the Niagara River. The compound concentration profiles in the sediment are in good agreement with the history of the dumpsite's use. The concentrations of the compounds start: to increase in the ea rly 1950s and maximize in about 1970 in the main portion of the lake. The Hyde Park Dump was closed in 1975; however, the compounds' concent rations in the surficial sediments are still about 20% of their maximu m. We attribute these relatively elevated levels to a combination of p hysical perturbations in Lake Ontario and continued migration of the c ompounds from the dumpsite. Using core burdens and concentration profi le data, we conclude that the sediment of the Kingston Basin of Lake O ntario is not directly connected to the nearshore zone and that the co mpounds were transported to the Kingston Basin sequentially from the R ochester Basin. We also observed a change in relative abundances betwe en the source and sediment for these compounds. The change was due to physical partitioning of the compounds between the sediment and aqueou s phases in the lake.