Whatever the merits of the case against the Keystone XL tar sands pipeline, its advocates are not just fading away into the sunset.  In the latest contentious round, US Army Corps of Engineers issued approvals for the crossing of hundreds of waterways along the 1184 mile path from Canada to Nebraska. Environmentalists promptly filed another lawsuit to stop further development of the $8 billion tar sands pipeline, claiming the Army Corps did not examine the potential for oil spills and other damages in a pristine environment.

In addition, the environmentalists filed notice that they intend to sue President Donald Trump over the pipeline’s potential harm to imperiled species. They say building the line would kill birds such as the whooping crane and piping plover and an endangered fish, the pallid sturgeon.

First proposed in 2008, Keystone XL was rejected by President Barack Obama but revived under Trump. An appeals court last month lifted an injunction that blocked construction of the project. That came after Trump issued a new permit in a bid to nullify a legal challenge to the pipeline by cancelling its previous permit.

The U.S. Army Corps public affairs office said in response to queries from The Associated Press that it was not commenting because the matter is under litigation.