Tar sands crude oil pipeline companies may be putting America's public safety at risk. Increasingly, pipelines transporting tar sands crude oil into the United States are carrying diluted bitumen or "DilBit" -- a highly corrosive, acidic, and potentially unstable blend of thick raw bitumen and volatile natural gas liquid condensate -- raising risks of spills and damage to communities along their paths. The impacts of tar sands production are well known. Tar sands extraction in Canada destroys Boreal forests and wetlands, causes high levels of greenhouse gas pollution, and leaves behind immense lakes of toxic waste. Less well understood, however, is the increased risk and potential harm that can be caused by transporting the raw form of tar sands oil (bitumen) through pipelines to refineries in the United States.