Oil and gas pipelines could be made safer if pipeline operators had clear guidelines for how quickly they must respond to accidents — but federal regulators don't have the data they need to establish those rules, according to a report by the Government Accountability Office, an independent arm of Congress.

The first few minutes and hours after a pipeline accident are considered crucial for effective cleanup and damage prevention. But the Pipeline and Hazardous Materials Safety Administration, which regulates the nation's 400,000-mile network of large volume transmission pipelines, requires only that operators respond in a “prompt and effective” manner.

The GAO urged the agency to replace this open-ended regulation with performance-based standards — specific, measurable goals that would make it easier to determine when operators have been negligent. To do that, PHMSA would have to set different rules for different types of pipelines depending on their contents, location, operating pressure, pipeline diameter and other factors.

Matthew Cook, a GAO senior analyst and a co-author of the report, said that to create those rules, PHMSA must first determine how fast operators are currently responding to accidents. But the GAO report warned that PHMSA's existing database, where pipeline accident information is filed, is incomplete and often inaccurate.

For instance, PHMSA requires operators to report the time the incident happened, but not when they first became aware of it or when they arrived on scene. And although operators are required to update PHMSA as more facts become available, companies continue to submit inaccurate data.

In 2010, after a massive oil spill in Michigan's Kalamazoo River, pipeline operator Enbridge Inc. initially reported to PHMSA that the accident occurred at 11:41 a.m. on July 26, which is when the company discovered the spill. It was soon determined that the spill actually happened 17 hours earlier, but Enbridge's subsequent reports did not correct that inaccuracy.

The timing discrepancy was highlighted last summer, when PHMSA fined Enbridge $3.7 million for breaking 22 federal rules during the Kalamazoo spill, including $100,000 for reporting the time of accident as “11:41 on July 26, 2010, when it had been clear within hours of discovery that the failure date and time was approximately 17:58 on July 25, 2010.”

Despite that fine, Enbridge did not correct the error in its most recent report to PHMSA, filed less than two months ago.

Enbridge's mistake is a common one. When InsideClimate News analyzed the 255 final incident reports that crude oil pipeline operators filed to PHMSA between January 2010 and February 2012, it found that 145 of the reports said the spill occurred at the same time that the operator discovered the problem.

“The reports don't give enough good data to make good decisions,” said Carl Weimer, of the Pipeline Safety Trust, which supports stronger pipeline regulations. “The data now is so squishy, you couldn't set a standard.”