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Pipelines are the chief method of crude oil transport in the Great Lakes region. Over 9000 miles of the binational U.S./Canadian crude oil pipeline system lies within the Great Lakes basin and it is estimated that pipelines account for more than 90% of total crude oil volume received by U.S. refineries in the Great Lakes. Pipelines are generally considered the safest and most efficient method of transporting crude oil, having the lowest incident and fatality rate per volume of oil transported. However, pipeline oil spills can be difficult to respond to and may have lasting impacts on the environment and regional economy due to the high potential volume of oil released. These challenges were highlighted by the Kalamazoo River oil spill in 2010. The continued operation of other pipelines – including Enbridge’s Line 5, which runs under the straits of Mackinac – has sparked public concern over the quality of pipeline infrastructure in the region.

Where does oil transport by pipeline happen in the Great Lakes region?

The map below shows major crude oil pipelines in the Great Lakes region, the location of crude oil pipeline terminals, and the location of active refineries. Note that crude oil is often transported from terminals to refineries via smaller pipelines that are owned and operated by the individual refinery. These smaller pipelines are not shown on this map. Data sources: U.S. Department of Homeland Security, U.S. Energy Information Administration

What are the benefits of oil transport by pipeline?

  • Can move high volumes of oil relatively quickly and at lower cost
  • Low incident and fatality rates compared to other transportation modes
  • Extensive infrastructure already exists in the region

What are potential drawbacks of oil transport by pipeline?

  • Spills may be difficult to detect and respond to quickly, especially in remote regions or buried/lakebed pipelines, resulting in high volume spills
  • Large environmental impact of high-volume spills resulting in long-term ecological or economic damage
  • Aging pipelines are costly to repair, monitor, and maintain
  • Subject to natural hazards and extreme weather conditions

What causes spills to occur?

  • Aging infrastructure failure
  • Rupture from natural hazards or extreme weather (freeze-thaw cycle, flooding, shoreline/lakebed erosion, etc.)
  • Anchor strikes in submerged pipelines
  • Sensor failure or monitoring oversight


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