A proposed $7 billion Canada-to-Texas pipeline cleared a major obstacle on Friday with the release of U.S. State Department review that suggested it would have limited environmental impact.

The U.S. Environmental Protection Agency raised new concerns about TransCanada Corp's proposed $7 billion Keystone XL pipeline that would bring oil sands crude from Canada to refineries in Texas.

In a letter to the State Department, the EPA cited two small leaks on an existing Keystone line last month as cause for alarm.