The formation, transport, and breakup of submerged oil-particle aggregates in Great Lakes riverine environments

The formation, transport, and resuspension of oil-particle aggregates (OPA) in freshwater environments are of much interest to oil spill responders and scientists, especially as transportation of light and heavy crude oils has substantially increased across river corridors and coasts in the Great Lakes Basin. The persistent sheening from accumulated OPA along 60 km of the Kalamazoo River in Michigan’s lower peninsula resulted in a lengthy and expensive cleanup for the 2010 Enbridge Line 6B pipeline rupture. The interaction of oil with river mineral sediment and organic matter and its long-term fate depend on the physical properties of the oil and particles as well as the environmental setting of river, its climate, morphology, currents and mixing opportunities. This research brief describes the expanded work conducted for the cleanup for the 2010 Enbridge Line 6B pipeline rupture and includes laboratory experiments of aggregate characteristics with Cold Lake Blend and a range of sediment particle sizes, addition of an OPA formation algorithm to an existing sediment contaminant transport model, and development of a simplified, particle-tracking based rapid response model of OPA formation, transport, and deposition. A description of formulas developed for mixing energy in rivers in terms of river properties is also included.