A controversial 1,711-mile pipeline that would link Canada’s tar sands to refineries in Texas and the Gulf Coast has passed a critical hurdle, even as environmental advocates continue to demonstrate outside the White House in opposition to the project. While the project must still must pass several key steps, State Department officials said Friday that the owners of the proposed Keystone XL pipeline, TransCanada, had agreed to take steps to minimize the risks of spill, and many expect the Obama administration to approve the project in some form by the end of the year. The State Department report, which said the project would not cause significant environmental damage, falls short of addressing concerns by the U.S. Environmental Protection Agency about the effects on air quality, drinking water, and endangered species. Environmental advocates have condemned the project, saying it will commit the U.S. to a dirty form of oil and pose ecological risks across the length of the pipeline for decades to come. Nearly 400 protesters have been arrested so far in the ongoing demonstration in Washington, D.C., including activist Bill McKibben and longtime environmental leader James Gustave Speth.