Released one day before the U.S. Senate votes on the Keystone XL pipeline, a new analysis of federal records shows that in just the past year and four months, there have been 372 oil and gas pipeline leaks, spills, and other incidents, leading to 20 deaths, 117 injuries, and more than $256 million in damages.

The Center for Biological Diversity analysis is based on decades of records from the federal Pipeline and Hazardous Materials Safety Administration, which maintains a database of all U.S. pipeline incidents that are classified as "significant"—those resulting in death or injury, damages more than $50,000, more than 5 barrels of highly volatile substances or 50 barrels of other liquid released, or where the liquid exploded or burned.

In total there have been more than 8,700 significant incidents with U.S. pipelines involving death, injury, and economic and environmental damage since 1986, the Center reports—more than 300 per year.

"There’s no way to get around the fact that oil and gas pipelines are dangerous and have exacted a devastating toll on people and wildlife. It’s appalling to see Congress seriously considering giving the green light to Keystone XL," said Bill Snape, senior counsel with the Center for Biological Diversity. "The Obama administration’s own analysis says Keystone XL will spill oil, so it’s really troubling to see politicians wanting to add to this dangerous legacy of failed pipelines."

The time-lapse video below includes every "significant pipeline" incident in the continental United States—along with their human and financial costs—from 1986 to Oct. 1, 2014. On average one significant pipeline incident occurs in the country every 30 hours, according to the data.