Late last year, Canadian pipeline company Enbridge and Enterprise Products Partners agreed to reverse the direction of crude oil on the Seaway pipeline so it can carry heavy oil from a major hub in Cushing, Okla., to refineries along the southern coast of the United States.
Enterprise said reversing crude oil deliveries on the 500-mile pipeline could reduce transportation costs and accelerate development of crude oil reserves in North America.
The move was seen as a response to delays in the Keystone XL pipeline from Canada. Opponents of tar sands say that type of crude oil is more toxic than conventional crude.
"These are pipelines of poison that are carrying products that are twenty times more acidic," Tom Smith, an advocate with Public Citizen, told Texas public radio KERA.
The pipeline could operate with a reversed service capacity of around 150,000 barrels per day by the second quarter of 2012. Upgrades to Seaway could increase its capacity to 400,000 bpd by early 2013.
Smith said crude oil from Canada would eat through the Seaway pipeline. Rick Rainey, an executive from Enterprise, however, told the broadcaster that his company was "comfortable that the safety measures in place are going to be adequate."