72 June 2019 _ PopularMechanics.com
TREVORPAULUSFROM THE GAS METER in Omayra Figueroa’s castle, a steel pipe at
least a half inch in diameter descends into the earth and elbows at
90 degrees toward Chickering Road, connecting to the main line
that carries natural gas into her home. The gas heats Omayra’s
hot water, dries her family’s sheets and towels, warms her radi-
ators on New England winter mornings, and flares blue, orange,
and yellow through the burners of the stove when she cooks rice
and beans for the kids.
From Chickering, the gas main runs in a two-foot-wide cor-
ridor below the roadways on the surface, according to Audrey
Schulman, executive director of HEET—the Home Energy Effi-
ciency Team—a nonprofit that has done work mapping gas leaks.
A sprawling underground network connects to the intermediate
line, then to the high-pressure interstate pipelines that funnel
natural gas into Massachusetts, the majority of it from the rich
fossil-fuel deposits of Pennsylvania’s Marcellus Shale. Four thou-
sand nine hundred eighty-nine and a half miles of gas-main lines
of the state’s underground pipeline network belongs to a utility
company called Columbia Gas of Massachusetts. A subsidiary of
the utilities giant NiSource, Columbia Gas runs its gas through
some of the nation’s oldest pipelines. These aging pipes are made
of cast iron, a brittle metal with a low pressure tolerance. In the
Northeast, earth resettles after freezing and thawing, a phenom-
enon known as frost heave. This can cause ruptures in fragile,
old pipes. Massachusetts, with an average winter temperature
of 27.6, has the third-most cast-iron pipeline miles of any state
in the nation.
Like other utility companies across the Northeast, Columbia
Gas has been steadily replacing its vulnerable cast-iron gas mains,
from 833 miles in 2005 to 471.4 in 2017. Its pipeline system is a
patchwork of materials from different eras—cast iron, bare steel,
and plastic—each with its own tolerance. For cast iron, it’s 0.5 psi,
roughly the pressure required to blow up a toy balloon. For bare
steel, it’s 60 psi or higher, and for plastic, 100 psi. At different
points in the system, valves regulate gas pressure in accordance
with the tolerance of each segment of pipeline.
Columbia Gas repairs more than 1,200 leaks annually. Last
April, it reported that 15
percent of its lines in Massa-
chusetts were “leak prone”
due to issues like rust, cor-
rosion, and failed welds.
Since the deregulation of
the gas industry in 1997,
state and federal oversight
of this infrastructure has
been limited. The process
is heavily reliant on self-
reporting, with utilities
performing their own safety
inspections, and federal or
state inspectors making
spot checks. The Massachu-
setts Department of Public
Utilities has only two engineers conducting field inspections of
the state’s 21,714.5 miles of gas main. The Pipeline and Hazard-
ous Materials Safety Administration has no power to impose a
deadline for pipeline replacement.
In recent years, the Department of Public Utilities has fined
Columbia Gas tens of thousands of dollars for a variety of safety vio-
lations, The Boston Globe has reported, including: “faulty pressure
testing and response procedures, insufficiently covering new ser-
vice lines, improperly classifying leaks, and breaking rules around
the use of leak repair kits.”Even though only 2 percent of distribution mains nationwide
are made of cast iron, they accounted for 41 percent of all fatali-
ties involving gas lines between 2005 and 2017. Twenty states in
the U.S. have eliminated ca st iron from their net works a ltogether.South Union and Salem Streets, Lawrence
Approximately 3:45 P.M.
A MILE NORTH of Omayra Figueroa’s home, on the Salem Street side
of the O’Connell South Common, a public park, a contractor removes
a length of cast-iron pipe, caps it, and sets it aside.
Feeney Brothers Utility Services (“Providing Underground Util-
ity Services since 1988”) has a permit to open up a two-foot-wide,
340-foot-long stretch of Salem Street, for the purpose of “complet-
ing gas main tie-ins and retirement of dual cast-iron gas mains.”
Feeney Brothers is a family-owned operation with seven hun-
dred employees. They’ve worked extensively not only for Columbia
Gas but also for the region’s other major natural-gas supplier,
Eversource. In recent years, gas utilities in Massachusetts have
increasingly relied on contractors to carry out projects like this.
It’s usually cheaper.
The job today is to install new polyethylene pipeline and tie it
into a new distribution main, also plastic. The Feeney Brothers
contractor may or may not be aware that a regulator sensing line—
a gauge that measures gas pressure—is attached to the pipe he had
discarded. But it’s important to note that he and his crew are per-
forming their duties as directed, under Columbia Gas supervision,
and correctly following the steps in the work package Columbia Gas
developed and approved. Columbia Gas’s work order doesn’t men-
tion the sensor and was not prepared by a professional engineer.
Until four years ago, a technician from the Meter and Regulation
Department would have been assigned to the site to monitor pres-
sure readings on the affected section of gas main, but Columbia
Gas, for undisclosed reasons, has ended this practice.
The sensor on the discarded length of pipe thinks
it’s still measuring the gas pressure in a vast under-
ground network. In fact, it is measuring nothing: The
pipe has been disconnected from the network. The
sensor might as well be attached to a hot dog. But the
sensor doesn’t know any of that, and there is no other
sensor in this segment of the network to contradict it.
The sensor sends a message to the regulator valves in
this segment of the network: Boost the pressure! Which
they do. But the sensor, because it’s still attached to the
dead piece of pipe, doesn’t detect any of that. Instead,
it registers a pressure drop, all the way down to 0.01
psi. More pressure, it tells the valves, until they have
opened completely, and two distribution systems that
were supposed to be segregated, cordoned off from
each other, are instead tied directly into each other for
twenty-six minutes.
A wave of high-pressure gas rushes into the regional
gas-main system that ser ves Law rence, A ndover, and
North Andover. In the older cast-iron segments of the
network, the pressure rises to at least 6 psi, twelve
times what the pipes are capable of handling.
At 4:04 p.m., the first high-pressure alarm is received
by the NiSource monitoring station—in Columbus,
Ohio. A second alarm is received at 4:05 p.m.
In the control room in Ohio, the NiSource employees
have no capacity to control, let alone shut down, the gas
flow. They can only contact the Meters and Regulations
Group at Columbia Gas, which at 4:06 p.m. dispatches
its entire team of inspectors to investigate—a total of two
people, or approximately one per 2,494.75 miles of pipe.THE EXPLOSION
TURNED THE
ROOM SIDEWAYS.
SHE YELLS THE
NAMES OF HER
CHILDREN, AND
FINALLY HEARS
HER DAUGHTER’S
SCREAMS.