Polishak is supervising a small crew digging up a snow-covered, frozen parkway in front of a house on Chicago's northwest side. They create a trench more than 5 feet deep to find where a water pipe is leaking.
This is a common problem this winter. Most water pipes in Chicago are buried 5 feet deep, which is usually below the frost line, but record-cold temperatures caused the ground to freeze much deeper than normal.
As the ground freezes, it expands, causing the frozen soil to shift and push against the aging water pipes. That movement can cause the pipes to bend and crack. The same thing has been happening in natural gas pipes, causing a huge increase in gas leaks under city streets this winter.
After removing the rusting piece of water pipe and joint called a "buffalo box," Polishak shows the damage.
"You see how this was supposed to be straight?" he asks, pointing to a slight bend in the pipe. "It literally pulled this thing up, and it broke the joint."
Age is also coming into play:
As weather starts to warm, another problem develops. The pipes are old — really old — and they can break as the temperature fluctuates back and forth. "We've got 4,400 miles of water main across the city of Chicago; about a quarter of that is 100 years or older," he says.Then we have the East Harlem explosion that destroyed two buildings and killed at least 8 people and injured 60. Investigators don't know what caused the explosion, but they suspect a natural gas leak:
It's not just water pipes. Aging catch basins and sewer lines are crumbling, too — some of which are so old they're made of brick.
And, of course, potholes are opening up on roads and bridges everywhere.
The NTSB is assuming that the blast was caused by a natural gas leak but hasn't ruled out the possibility that an apartment's stove could be to blame, Sumwalt said.Whether it was from a leak at the main, or a leak inside the building, I would suspect that the age of the pipe may have played a part. The New York Times is reporting the gas main that served the building was installed in 1887. We are increasingly going to find that our infrastructure is failing and we can't afford to update it. We're going to see a slow decline in our standard of living as previously reliable utilities become less dependable. At the same time, lives will be lost. Stories like this one in East Harlem will be more common.
He noted that the gas main and distribution pipe were intact, which is different from other explosions where pipes have been blown several feet from a building.
"We will be constructing a timeline," Sumwalt said. "We aren't sure how long the leak was there."
The NTSB will try to determine whether there is a relationship between the explosion and a nearby water main break.....
The cause of the blast has centered on reports of leaking natural gas. De Blasio said the explosion erupted only minutes before a crew from the Con Edison power company arrived to check for a reported leak..
Elhadj Sylla, whose wife owns a store nearby, said he was about a block away around 8:45 a.m. when he noticed a faint smell of gas.
Ruben Borrero, a tenant in one of the destroyed buildings, said residents had complained to the landlord about smelling gas as recently as Tuesday.
A few weeks ago, Borrero said, city fire officials were called about the odor, which he said was so bad that a tenant on the top floor broke open the door to the roof for ventilation.
"It was unbearable," said Borrero, who lived in a second-floor apartment with his mother and sister, who were away at the time of the explosion. "You walk in the front door and you want to turn around and walk directly out."
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