Modeling the transport of oil–particle aggregates resulting from an oil spill in a freshwater environment

Transport of oil through pipelines is at an all-time high and so is the risk of oil spill accidents. The July 2010 spill of diluted bitumen into the Kalamazoo River was the largest release of heavy crude into an inland waterway in the history of United States. After extensive cleanup and recovery efforts, substantial residual deposits from the oil spill remained in the river system, mainly due to the formation of oil–particle aggregates (OPAs). Understanding the conditions under which OPAs can be suspended, transported and deposited is important for river management. Concerns about OPAs reaching Lake Michigan motivated this work. A three-dimensional Eulerian/Lagrangian model for OPA transport was developed for Morrow Lake in the Kalamazoo River, using specified OPA properties based on laboratory experiments. The three-dimensional model included the Morrow Lake dam operational rules as well as wind effects, which might increase the risk of resuspension and transport of OPA downstream. The usage of the model as a management tool is illustrated; the suitability of the model framework to incorporate the more complex processes of OPA formation transformation is discussed.