LimnoTech
Diver deployment of bottom sediment sampler
Success Story
Sediment trap studies support sediment transport modeling
Investigations are being conducted to characterize the fate and transport of substances released in the upper Tittabawassee River and transported via the Tittabawassee to the Saginaw River and downstream. A fundamental component of these investigations has been to improve the understanding of sediment transport dynamics in the river. LimnoTech’s expertise in implementing sediment transport field studies provided critical data to support development of a sediment transport model for use in evaluating remedial alternatives.
Problem
Elevated levels of dioxin and furan have recently been identified in the sediments of the upper Saginaw River. The use of sediment traps to manage river sediment could provide an innovative, cost-effective remediation strategy. Critical data related to sediment composition, settling rates, and chemical constituent levels were needed to allow evaluation of whether sediment traps could be effective in capturing sediments and associated contamination.
Approach
Ship turning basins in the navigation channel of the river are well suited to trapping sediments and provided a good location for studies of sediment depositional behavior. LimnoTech employed several techniques to investigate high flow event and longer-term sediment dynamics in the water column and on the channel bottom. LimnoTech coupled conventional sampling and laboratory analysis methods with state-of-the-science instrumentation deployments to measure suspended sediments (OBS3+) and particle-size distribution (LISST-100X). LimnoTech designed, constructed, and deployed bottom sediment samplers to measure settling rates, and used conventional bedload samplers to monitor sediment movement along the river bottom.
Result
LimnoTech’s work provided the crucial data needed to support an enhanced understanding of sediment transport and deposition dynamics in the Saginaw River. The data are being used for model development and assessments of the feasibility of remedial alternatives.