[7] Shippers dilute bitumen before shipment in order to meet viscosity and density requirements found in common carrier pipeline tariff rules.
A National Energy Board study assumed a standard dilbit containing 33% condensate (resulting in product with "21.5 °API and sulphur content of 3.3 percent") and synbit containing 50% SCO.
[15] During the 2010 Kalamazoo River oil spill, the heavier components combined with silt and sank to the bottom of the water column, making cleanup difficult.
We also recommend that the Final EIS include means to address the additional risks of releases that may be greater for spills of dilbit than other crudes.
For example, in the Enbridge spill, the local health department issued voluntary evacuation notices based on the level of benzene measured in the air.
In coastal marine ecosystems, such as those found in British Columbia, Canada, dilbit floats on the surface because it is too light to sink, unless it is significantly weathered.
Dilbit is harmful to a wide range of marine animals, including sea otters, baleen whales, fish embryos, and juvenile salmon.
[24] The effects of dilbit on freshwater ecosystems have come into focus in the late 2010s, particularly by researchers at the Experimental Lakes Area and Queen’s University, both in Ontario, Canada.
[26] Total insect emergence also decreased with increasing dilbit concentration, and the oil likely drove water strider immobility and death.