Thousands of miles of aging natural-gas pipelines in Ohio are made of untreated steel that is prone to corrosion, according to federal pipeline data.
Columbia Gas of Ohio started replacing the out-of-date pipe on its lines in 2008, but it will take $2 billion and 23 more years before the job is completed, said Ken Stammen, a Columbia Gas spokesman. The project already has replaced lines in Columbus’ Linden neighborhood east of I-71 and north of Hudson Street.
“Age is something that we consider when we’re making decisions about what pipeline we’re going to replace in a certain year,” Stammen said. “We also look at bare steel or uncoated steel, cast iron or wrought iron, pipes that aren’t coated or are not treated to prevent corrosion.”
The explosion of a massive transmission pipeline under a California neighborhood this month killed four people, injured 50 and destroyed 37 homes. It left people nationwide who live near such lines wondering about their safety.
Federal maps show similar transmission lines — the large arteries that move gas between cities and states — running beneath heavily populated areas of central Ohio. Almost all those lines are made of steel that has been treated to resist corrosion, federal data show.
The major lines run near Bethel Road on the Northwest Side, Weber Road in Clintonville and Kenny Road in Upper Arlington. In Gahanna, one runs between City Hall and police headquarters and then through a subdivision to the east. It’s marked with white poles with orange tips.
Gahanna officials were concerned enough after the California explosion to ask Columbia Gas for assurances.
“We’ve been very comfortable with what we’ve seen from Columbia Gas,” said Terry Emery, the city’s public-service director.
Only 49 miles of pipeline out of 10,125 miles of the major gas transmission lines in Ohio are not treated to resist corrosion, federal data show.
It’s the next size of lines, the distribution mains that move gas throughout cities, where the older, untreated pipes are. Nearly half of Columbia Gas’ 19,733 miles of gas mains in Ohio are more than 40 years old, and 3,722 miles of those mains are not treated to resist corrosion. Columbia Gas has about 5,700 miles of mains in the Columbus area, Stammen said.
The mains range in size from less than 2 inches to 2 feet in diameter.
Crews walk along the largest lines in heavily populated areas with gas detectors, inspecting for leaks, at least twice a year, Stammen said. Smaller lines are inspected annually.
The company runs robots called “smart pigs” through the lines every seven years to check for corrosion, cracks, dents and other problems, he said.
Columbia’s largest lines, which are as big as 24 inches in diameter, are monitored 24 hours a day at a command center on Civic Center Drive. If there’s a problem, Stammen said, “we can reroute the flow of gas or shut off the flow of gas.”
Nationally, 83,166 miles of gas mains were made of unprotected metal. In all, there are more than 1.2 million miles of gas mains, federal data show.
Age and corrosion resistance are factors in pipeline safety, said Carl Weimer, executive director of the Pipeline Safety Trust, a nonprofit watchdog group that was set up after a fuel spill killed three children in Bellingham, Wash., in 1999.
But “what really matters is how well the companies have operated, maintained and inspected their pipelines,” he said. “New ones can fail because the company didn’t do those things well.”
The Public Utilities Commission of Ohio inspects pipeline operators in Ohio each year in partnership with federal regulators, said Shana Eiselstein, spokeswoman for the commission. Inspections include physical checks of the pipeline, reviews of records and observations of crews at work, she said.
Columbia paid a $10,000 fine this year for not properly testing a coupling from a failed gas line that led to a Strongsville home where there was a fire. It was the only enforcement action the PUCO has recorded against the company in the past three years, Eiselstein said.
From 2000 through 2009, there have been 21 “major incidents” — usually gas fires or explosions — on lines owned by Columbia Gas or its partner Columbia Gas Transmission in Ohio. Three people were killed in the incidents and eight were injured.
The incidents caused more than $5.5 million in damage, according to the U.S. Pipeline and Hazardous Materials Safety Administration.
The most common cause of those fires and explosions was third-party excavators hitting a line. But corrosion was listed as the cause in three cases, including two in which someone was injured. Those incidents occurred in Cambridge, Toledo and Marietta.
To put that in perspective, it works out to about a 1-in-10,000 chance per year of a major incident on any given mile of Columbia’s system in Ohio.
Columbia Gas is proud of its safety record, Stammen said.
Dominion East Gas and its interstate partner Dominion Transmission, which operates a natural-gas transmission line that crosses the southeastern corner of Franklin County near Canal Winchester, have had seven major incidents in Ohio in the past 10 years.
Those incidents caused about $4.9 million in damage and resulted in one death and two injuries, federal data show.
Dominion’s system, almost as large as Columbia’s, mainly serves northeastern Ohio.
Authorities are still trying to determine what caused the California explosion, and gas company officials are watching.
“The root cause will go a long way to determining what our next steps are going to be,” Stammen said.