TRANSPORTATION OF TRACE METALS IN THE OTTAWA RIVER, NORTHWEST OHIO

Sediments in the lower parts of Ottawa River in Toledo, Ohio have a known history of contamination. Upstream studies have not shown a significant amount of contamination in sediments, but have found some metals present within the fine grained and/or organic material in sediments. This contaminated material is easily transported in the suspended load down the Ottawa River. It has not been determined if the metal contamination is being carried down the river as part of the dissolved load or part of the suspended load. To determine which transport mechanism is more important, filtered and unfiltered water samples were collected from the upper Ottawa River at 3 sites in the Wildwood Preserve Metropark and at 2 sites in Secor Metropark. Samples were also collected to determine the total amount of suspended material in the river. Secor Metropark is located in a rural area, while Wildwood Preserve Metropark is surrounded by urban areas. Total Suspended Solids (TSS) were analyzed by filtering water samples through coarse, medium, and fine filter paper The TSS correlated to the discharge in Secor Metropark but was not correlated in samples from Wildwood Preserve Metropark. Unfiltered water samples were digested following the procedure in EPA method 3105a. All water samples were analyzed for selected major and trace elements using the Inductively Coupled Plasma-Optical Emission Spectrometer (ICP-OES) at Bowling Green State University. With the exception of Sr, trace metal concentrations in the filtered samples were generally less than 1ppm. Elemental concentrations varied slightly in samples collected in a single day at each park. There were also differences in elemental concentrations between the metroparks. Furthermore, variations at each sample point were seen in elemental concentrations throughout the sample period. The concentration of major elements and trace metals were either positively or negatively correlated with discharge.