WASHINGTON — Three powerful accidents in recent years highlight weaknesses in the oversight of how natural gas providers maintain the largest pipelines in their networks, accident investigators said Tuesday as they issued more than two dozen safety recommendations.
A major effort a decade ago by the federal government to check a rise in violent pipeline failures in “high consequence” areas where people are more likely to be hurt or buildings destroyed has resulted in a slight leveling off of such incidents but no decline, the National Transportation Safety Board said.
And while the frequency of such accidents remains low, they are still more likely to occur in more densely populated areas despite increased safety efforts in those areas, the report found.
More safety improvements are needed “to prevent catastrophic gas transmission line accidents from ever happening again,” said Chris Hart, the acting NTSB chairman.
A steady increase in pipeline explosions and fires in the 10 years prior to 2003 prompted the Pipeline and Hazardous Materials Safety Administration to adopt safety standards in 2004 for inspecting and maintaining the physical integrity of pipelines, with priority given to high-consequence areas.
Since then, state-regulated pipelines — those that don’t cross state borders — have had a 27 percent higher incident rate than federally regulated pipelines that traverse more than one state, the report said.
The concern then and now is that aging pipelines will rupture in populated areas. The U.S. is crisscrossed by nearly 300,000 miles of gas transmission pipelines, more than half of which were installed before 1970. The pre-1970 pipelines have a significantly higher failure rate because they have been exposed to environmental forces longer and newer pipelines have been made with improved safety technology, the board said.
There is wide variation in states’ approaches to pipeline-safety oversight in high-consequence areas, and there isn’t enough federal-to-state and state-to-state coordination between inspectors, the board said.
The board issued 28 recommendations as the result of the report, most of them to federal regulators. They urged states to adopt more costly pipeline-inspection methods that are more likely to find problems.
The board also urged improvements to a pipeline mapping system so states and operators could better determine which areas should be designated high-consequence and therefore given more attention.
