TransCanada (TSX:TRP) says it has had a co-operative relationship with the EPA throughout the four-year-plus review of the project.
On Monday, the EPA publicly denounced for a second time the U.S. State Department's favourable environmental review of the pipeline.
The pipeline company says the EPA recommends more comparison of greenhouse gas emissions from oilsands crude against U.S. crude oil, but ignores that the Canadian crude will be delivered by the pipeline, displacing heavy crude oil from Venezuela and Mexico.
TransCanada also says the EPA's recommendation that the State Department explore ways for the U.S to involve itself in ways to reduce emissions from the oilsands ignores Canadian sovereignty.
The company said Alberta implemented greenhouse gas regulations in 2007.
"Pipelines produce the fewest amounts of emissions to move oil to the markets where it is needed," TransCanada said Tuesday.
"Keystone XL will offset as many as 200 ocean tankers per year, reducing GHG emissions by as much as 19 million metric tons."
TransCanada has voluntarily agreed to 57 new safety procedures regarding the operating and monitoring of the pipeline, the company said.
The State Department will now review all the public comments, including the input from the EPA, before finalizing its draft report.
Ninety days later, State officials will then determine whether Keystone XL is in the national interest of the United States.
After that, it will be up to U.S. President Barack Obama to either block or bless the pipeline. A final decision is expected this summer.
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