Mass Balance Implications for Sediment Restoration Initiatives in the Detroit River, USA.

Contaminated sediments remain an important management issue in the Detroit River Area of Concern (AOC). This study evaluated the likely impact of proposed U.S. sediment restoration actions on organic and inorganic contaminant mass inventories and benthic invertebrate toxicity. Currently, 4.5 km2 of sediments are designated for restoration in U.S. waters across six major restoration zones. High-resolution sediment contamination maps generated using deep learning artificial neural network (ANN) spatial interpolation were used to assess prospective changes in chemical mass balance and reductions in areas exceeding probable effect concentration (PEC) sediment quality guidelines. Restoration zones contain between 4.0 and 17.2% of the total U.S. contaminant mass inventory; however, accounting for upstream infilling, restorations are expected to reduce total contaminant mass by 2.0-16.1% across individual chemicals. Upwards of 4.2 km2 of sediments will revert from exceeding PEC to lower than PEC concentrations across priority contaminants reducing potential toxicity to benthic invertebrates.