Iron or plastic? You'll take plastic, thank you, for your new gas main

Hidden under streets, sidewalks and lawns across Michigan — even spanning muddy lake bottoms — are pipelines with explosive potential.

If the natural gas in those pipes escapes to mix with air, bam … there can be disaster.

Three times last May and June, neighborhoods in Grosse Pointe Woods were evacuated when workers replacing natural gas mains accidentally ruptured existing mains — and a fourth time from a sewer crew's underground flub.

That sent potentially explosive gas hissing into the air. Fortunately, no harm was done by an effort aimed at making gas mains, ultimately, safer.

"There were no explosions — no boom, no fire, just hissing sounds," said Peter Ternes, manager of communications for DTE Energy’s gas division, of the four mishaps in Grosse Pointe Woods.

And there was no repeat of the tragic accident in Royal Oak in 2014, when a homeowner died in an explosion after a Consumers Energy crew replacing a steel gas main dating to 1929 failed to follow safety procedures. 

Stunned by the risk after this year's mishaps, DTE Energy officials froze the action not only in the Grosse Pointes but across the state.

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"We stopped all work, and we had our contractors review all of their safety practices and then come back with recommendations for improvements. After a one-week stand-down, we had them resume work but at a slower pace, so we could ensure that we could prevent any future accidents," Ternes said.

DTE Energy is better known for winning safety awards. The company's only recent natural gas explosion in its pipeline network occurred in July 2016 in suburban Detroit, when a drunken driver crashed through a berm and a fence, then struck an aboveground gas pipeline near the company’s training center. In that incident, the only injured person was the driver, according to police reports.

But there's bound to be more close calls by utility construction crews — because Detroit-based DTE Energy, along with Jackson-based Consumers Energy and other utilities in Michigan, is heavily engaged in a sprawling and costly program to replace virtually all of the state's aging gas mains and the smaller supply lines that run to homes and businesses. If the massive project hasn't come to a street near you, it will eventually — although the utilities don't expect to be done until around 2040.

"The vast majority of building fires and explosions resulting from natural gas, more than 98%, are caused by leaks inside buildings," typically involving gas lines or appliances owned by customers, Ternes said. Most other cases involve a third party, such as the sewer-repair crew that struck a gas line in Grosse Pointe Woods.

The utility says  the process of replacing gas lines is safe, and the goal is all about safety as well — because brittle cast-iron gas mains and supply lines that run to houses and apartments, all subject to cracking and corrosion, are being replaced with flexible polyethylene mains and supply lines that could last a century.

Despite well-publicized laments about the world's proliferation of plastic litter, semi-rigid polyethylene is unexcelled as a pipeline material, Ternes said.  

"One of the benefits of the new line is that it can be squeezed to cut off the gas supply. But once you release the squeeze, it regains its original strength.

"That means if we have a break, we don’t have to go up and down the line looking for a valve. We can just squeeze the line during a repair, which aids the speed of repair and affects fewer customers," he said.

In Grosse Pointe Woods, the recent evacuations worried residents and caused inconvenience — like the guy who missed a job interview because he couldn’t go home to yank on a suit — but they were ordered from a sensible "abundance of caution," said Bruce Smith, the city administrator.

"People don’t realize — this is a massive undertaking," Smith said.

As lawmakers in Lansing and Washington dither and debate about spending tax dollars to rebuild the nation’s creaky, aging infrastructure, metro Detroiters should be glad that at last the crucial network bringing them natural gas is being renewed, he said.

Across Michigan, the project involves three huge utilities. Besides Detroit-based DTE Energy, state regulators have requested participation from Jackson-based Consumers Power and Port Huron-based SEMCO.

Through last year, SEMCO had replaced 163 miles of its natural gas mains, Consumers Energy finished 313 miles, and DTE Energy racked up 404 miles, according to records at the Michigan Public Service Commission — the state agency that regulates Michigan utilities.

This year in metro Detroit, DTE Energy has crews ripping up sidewalks and replacing gas lines in the Grosse Pointes, Harper Woods, Dearborn and parts of Detroit, as well as in isolated other areas where engineers fear that soil conditions are especially destructive to the old iron and steel pipes, officials said.

"Soil conditions play a big role in how much corrosion takes place," said Kim McCrary, a supervisor of gas operations for DTE Energy, and overseeing construction crews in Dearborn.

Consumers Energy has contractors performing similar work this year in Royal Oak, Plymouth, Auburn Hills, Waterford and six areas of Macomb County, spokeswoman Katie Carey said. A gas leak Friday in Royal Oak that required evacuating people from several houses was caused, not by the utility replacing gas mains, but by an unrelated construction job, police said. An emergency repair crew from Consumers Power, however, responded quickly to secure the site and repair the leak, Carey said. 

Nationwide, the epic task of replacing gas lines got jump-started when federal pipeline overseers investigated a deadly explosion in California that became a legendary trigger for change. On Sept. 9, 2010, just as people sat down to dinner in San Bruno, near San Francisco, a 30-inch steel gas main became a fireball that killed eight people — including safety advocate Jacqueline Greig, 44, who'd spent the summer studying the need to replace the region's aging gas lines.

San Bruno's explosion was a crucial spur to start replacing the nation's natural gas pipelines, a process that began slowing in Michigan in 2011, then ramped up rapidly last year and this. The San Bruno explosion, sparked concerns about the entire U.S. network of aging steel and cast-iron gas pipes, said Mike Watza, an attorney and expert on utility regulation at the Detroit-based Kitch Drutchas law firm.

"When you look at what happened out there, this is pretty important. We certainly don't want that happening in Michigan," Watza said.

Prevention isn't cheap. The cost averages a cool $800,000 per mile, according to DTE Energy. So, who's paying the tab? All of Michigan's gas customers are on the hook, with a small "IRM surcharge" added to each customer's monthly bill.

For most of DTE Energy's residential customers, the IRM charge is 35 cents per month — under a formula set by state regulators. For residential customers of Consumers Energy, the monthly charge will rise in August from 72 cents to $1.66, an increase approved Monday by the Michigan Public Service Commission.

"IRM" is utility-speak for Infrastructure Recovery Mechanism, said Nick Assendelft, spokesman for the MPSC and for the Michigan Agency for Energy, both in Lansing.

"We certainly see this as a safety issue," he said.

Contact Bill Laitner: blaitner@freepress.com