The federal government has quietly approved major tar sands transportation projects with unstudied environmental effects — managing to circumvent the executive branch’s impact analysis that paralyzed development of the Keystone XL pipeline and bolstered activists’ claims that the project is dangerous and damaging to the environment.

Over the past few years, the Keystone pipeline has become a household name. The controversy caused by Canadian pipeline company TransCanada’s project, which would bring hundreds of thousands of barrels of oil from Canada’s tar sands to the U.S. each day, has ignited an environmental movement across the country, and has elicited responses from top U.S. politicians, including President Obama.

But the U.S. has approved other cross-border tar sands transportation projects with little fanfare.

Those projects include one by TransCanada competitor Enbridge to build a facility in Illinois to transport crude oil from the tar sands via train, which was approved by the Federal Energy Regulatory Commission (FERC) last week. The decision came just weeks after the State Department approved an Enbridge pipeline project that would cross Canada through the Minnesota border and help bring millions more barrels of oil to the U.S. each year. The project was approved without a public review process or an environmental-impact assessment.

Environmental activists say the two approvals show that the tar sands industry is intent on getting tar sands oil to the U.S. regardless of whether Keystone is approved. And the approvals may show the industry has taken a lesson from the current Keystone debacle about how to move tar sands oil without public relations headaches.

“There’s been a pretty deliberate attempt to try and avoid the permitting process and public involvement,” said Doug Hayes, a staff attorney with the Sierra Club. “While everyone was paying attention to Keystone, there were all these other projects being approved behind closed doors.”

Pipelines that cross an international border need to go through an often-lengthy review process, and that is what has stalled TransCanada’s Keystone plans, as President Obama delays a decision on whether to approve the pipeline time and time again.

The Keystone XL pipeline has been one of the most contentious oil projects of the last decade for good reason: The pipeline would move as many as 830,000 barrels of oil from Alberta, Canada, to Nebraska, where it would then be transferred to other pipelines that snake their way down to Gulf Coast oil refineries in Texas and Louisiana. Environmentalists say the project would guarantee the further development of the tar sands in Canada — a previously pristine area that has been extensively mined for oil that’s particularly carbon-intensive to process. The mining of the sands (which are actually filled with oil-rich bitumen, not tar) has already produced enough annual greenhouse gases to rival the combined emissions of New Zealand and Kenya. And the Canadian government has pushed to triple tar sands production in the coming decade.

But as Obama’s decision (or lack thereof) on that pipeline receives the brunt of the public’s scrutiny, other projects that would also bring hundreds of thousands of barrels of tar sands oil to the U.S. have slipped by with barely a blip in the news.

Last Friday, FERC approved plans for an Enbridge rail facility in Flanagan, Illinois, that would help transport up to 140,000 barrels of tar sands oil per day across the Canadian border to the states. Flanagan is where Enbridge’s Flanagan South pipeline begins. That pipeline connects to another pipeline in Cushing, Oklahoma, which brings the oil down to refineries in the Gulf where it can be turned into usable fuels, or sometimes sold for export to other countries.

The approval came weeks after Enbridge was accused by environmental groups of blatantly skirting the federal review process in its quest to double the capacity of another project called the Alberta Clipper, which runs from the tar sands to Superior, Wisconsin, and then connects with pipelines that bring oil south.

If Enbridge wanted to double the capacity of the entire Clipper pipeline, it would have needed to be reviewed in the same fashion Keystone XL was, environmental groups contend. Instead, Enbridge proposed doubling capacity above and below the Canadian border, and connecting the two sections of pipeline with an already-existing pipeline called Line 3. Because Line 3 was already approved to cross the Canadian border into the U.S., the project, according to the State Department, did not necessitate federal review.

“The fact that Enbridge is doing all it can to avoid a permit review is a testament to how controversial Keystone has become,” said Jim Murphy, senior counsel at the National Wildlife Federation. “But if [oil producers] want to double and triple production in the tar sands, they’re going to need Enbridge, Keystone, and frankly more pipelines than that.”

Environmental groups say they’re considering legal action to challenge the State Department’s approval.

Some environmentalists are also worried about Enbridge’s safety record. In 2010, a pipeline owned by the company ruptured, spilling 1 million gallons of tar sands oil into the Kalamazoo River in Michigan. The spill was the largest inland oil spill in U.S. history, according to the National Wildlife Federation.

U.S. officials blamed the company for ignoring cracks in the pipe going back to 2005. National Transportation Safety Board chairwoman Deborah A.P. Hersman said the company experienced “a complete breakdown of safety” in the years preceding the spill.

The company was also accused of underfunding and understaffing cleanup efforts, leading the still ongoing cleanup to take years instead of the initially predicted one-month. The company was fined $3.7 million for the spill. An analysis of company records by the Polaris Institute shows Enbridge was involved in 804 pipeline spills and accidents between 1999 and 2010.

But the Michigan incident, or the potential for a similar one, wasn’t taken into account in the State Department’s approval of the company’s Alberta Clipper expansion plans.

While the approvals were big blows to the anti-tar sands movement in the U.S., environmentalists say Keystone XL still remains the largest single arbiter of the future of tar sands development.

Several analyses, including one funded by the Canadian government, predict that without pipelines and other means to get the oil to international markets, tar sands development will level off or decrease.

Obama denying a permit for the Keystone XL on the basis of its potential climate change impacts would set a precedent for other tar sands projects. And environmentalists hope the fact that Enbridge and others are looking at alternatives to cross-border pipeline projects that require federal approval may be a sign that companies fear the fate of the Keystone XL.

“Keystone is still the biggest game in town for a reason: If Obama rejects it that could have major implications for other projects,” said Jason Kowalski, the U.S. policy director for environmental group 350.org. “But in the meantime, we need to make sure every project goes through the same process that Keystone went through.”