Gas usage spiked in houses before recent explosions but measuring is difficult, expensive
It's difficult to know if the kind of house explosions that killed a Menno woman and severely injured a Mitchell man this summer could have been prevented.
But there were hints that such horrific incidents were about to happen. Shortly after the explosions, NorthWestern Energy released information showing gas usage in each home spiked between the last reading and explosions.
The problem, said Michael Sydow, general manager of NorthWestern retail operations for South Dakota and Nebraska, is a malfunction can create a dangerous situation in smaller areas without excess flow valves detecting potential disaster.
"There's not a fail-safe that you could never have a gas leak in a small room or in a basement," Sydow said.
The house explosions rocked neighborhoods and also shook people across the region.
Jose Aguirre, 38, was severely burned when his rental home in Mitchell exploded on Aug. 17. Aguirre is recovering from his injuries in a Minnesota burns treatment facility.
Six days later, Gail Guthmiller, 56, was killed when her Menno home was literally torn apart by an explosion.
Tom Glanzer, NorthWestern Energy spokesman, said the gas usage spikes in the houses weren't noticed until after the explosions because the meters are checked manually each month and not monitored by computers.
Glanzer said it's unclear if there ever will be computer monitoring of natural gas consumption,
The future is not yet set on that issue, according to the vice president of NorthWestern's retail operation.
"Those kind of things are really under constant evaluation," said Curt Pohl.
At this point, any sort of technology that could theoretically monitor spikes isn't cost-effective, Pohl said. Even if such a system was implemented, there's still no guarantee that it would prevent the house explosions like those in Menno and Mitchell, he said.
"It's a fairly significant cost to add that type of technology," Pohl said. "We will continue to evaluate new technology and things that we can be doing from our standpoint."
Pohl said NorthWestern has been installing the excess flow valves in new homes for nearly three years. The valves automatically shut themselves off when excess gas is detected.
Monthly visits by an actual person are also important for safety, Pohl said. During their visits, meter readers can discover potential problems, from the placement of a dryer vent that drips condensation -- which can eventually freeze and cause a malfunction -- to dog chains attached to a gas line.
"There have been automatic reading systems for a long time, but there's also some value having a meter reader going out to the premises too," Pohl said.
The first line of defense is still the odor put in gas to make it detectable to humans, Pohl said.
More than 1,000 scratch-and-sniff cards were distributed to attendees during this year's State Fair, one of a few signs that awareness about natural gas is increasing following local and state incidents.
"We do think we've seen an increase in the number of calls because of the heightened awareness, which is a good thing," Sydow said.