When a natural gas-related emergency occurs, all eyes are firmly fixed on the gas utility’s response, with television news crews rushing to the scene to capture breaking news for concerned citizens. But, in many cases, it’s after the emergency has passed—and after the TV cameras have moved on to the next big story—that the real problem-solving starts.
Spire crews in Kansas City, Missouri, experienced this firsthand in June when they coordinated their response to a large sinkhole that caused a natural gas leak and garnered two days of intense local news coverage.
Located in the middle of an intersection in a busy industrial area, the sinkhole was 40 feet across and more than 20 feet deep. Because the sinkhole was partially filled with water, the 24-inch steel main couldn’t be seen—making it impossible to determine the severity of the leak.
The public usually sees our response only when something goes wrong—when it’s big enough to draw media attention. Rarely do people get to see the level of dedication and coordination that is displayed by gas utility employees every day across the country ...
What could be seen was that a large concrete utility access box weighing thousands of pounds had collapsed onto the main when the ground was washed away underneath it. From above, the escaping gas could be seen bubbling up through the muddy water. It was a dramatic image that captured the attention of local media and fueled their coverage.
Spire crews sprang into action, focusing on shoring up the sinkhole to prevent additional collapse, evacuating the water to expose the damaged section of main and shut off the flow of gas. Two significant issues added to the challenge.
Only one Spire customer was being served by the affected section of main. However, turning off the flow of gas at the next valve station, a potential solution for similar issues, would have meant the loss of service to more than 300 customers, many of them small industrial operations.
The second issue was the water. The sinkhole occurred close to the Missouri River, which was running at near-record flood levels, causing the water table in the area to run higher than usual. As quickly as crews were able to pump the water out of the sinkhole, water was flowing back in. It ultimately took three high-capacity sump pumps to lower the water level enough to access and inspect the damaged section of pipe.
Once the pressure in the main had been reduced, the inspection revealed that the weight of the concrete utility box and the lack of any supporting ground underneath the box had caused the main to bow and partially separate from a dresser coupling holding the main together.
Forty-eight hours after the initial gas leak call, and with the situation under control, television news had moved on to other stories.
But Spire’s work wasn’t done. Leak and maintenance crews worked with engineering staff to design a repair. It was determined that the damaged section of pipe could be abandoned, and the main connected on either side would be cut and capped.
Work began immediately to relocate a regulator station that was tapped off the section of the to-be-abandoned main. Crews also began four additional excavations on either end of the section of leaking main—two to allow for the installation of new stopper fittings and two where the still-working main would be capped.
Crammed into a roughly 200-foot-by-200-foot space were the original sinkhole, four additional excavations and a regulator station being reset, plus numerous other utility contractors conducting their work. Over the next couple of days, crews worked in shifts around the clock with backhoes, dump trucks and other heavy equipment, all in those tight quarters, to get everything prepped for contractors and in-house crews to set the stoppers, cut the main and cap it.
At the start of every shift, safety briefings ensured everyone working on the site understood their role and how to account for the various hazards. Once the main had been capped, the crews went back to work breaking down the job site and backfilling the excavations while other utility crews continued their work in the sinkhole.
The total response and repair time for this incident was roughly five days. In that time, with all the heavy-equipment activity, the hazards presented by the instability of the sinkhole and the leaking gas, there were no injuries or other safety incidents on the job.
And despite the nature of the damage and repair, service was maintained for customers in the area who depend on natural gas to fuel their businesses.
The public usually sees our response only when something goes wrong—when it’s big enough to draw media attention. Rarely do people get to see the level of dedication and coordination that is displayed by gas utility employees every day across the country, even after the TV cameras stop rolling—a positive outcome that highlights the heroic efforts of utility workers and a story worth telling.
Gwen Janes is director of field operations at Spire.