Summer thunderstorms bring an impressive light show as they roll across the prairie, but they also can wreak havoc over the western North Dakota oil patch when they hit saltwater disposal sites.
At least four of those facilities have gone up in flames in McKenzie County since the beginning of June.
The county’s emergency manager, Karolin Jappe, is all too familiar with such incidents.
“In my five years, I have seen more saltwater wells go 'boom' than I can shake a stick at,” she said.
Saltwater is a byproduct of oil production and, when it surfaces, it needs to be disposed of because it can render farmland infertile for decades if it leaks into a field.
Trucks and pipelines carry the saltwater to disposal wells, where it’s processed in a series of tanks to separate out any oil before the brine is injected back underground.
Fires tend to occur when a spark causes the gases inside a tank to ignite, and then the fluid flows out.
Combined, the recent incidents in McKenzie County caused more than 11,400 barrels of brine to spill, equal to nearly half a million gallons, in addition to a lesser amount of oil. In each of those cases, state reports show that all fluid was contained on-site.
Jappe estimates McKenzie County loses five disposal sites each year. Many are struck by lightning, though sometimes static electricity can build up, resulting in a fire if a truck driver does not properly use a grounding rod at a facility, she said.
Jappe said fiberglass tanks seem to be particularly susceptible to damage from lightning, and she’s encouraging companies that operate disposal sites to use steel instead.
One company, White Owl Energy Services, is rebuilding one of its facilities with steel tanks coated by an epoxy on the inside to prevent corrosion.
“They’re rebuilding now but not using any fiberglass, and I’m so glad,” Jappe said.
That facility, near Watford City, was destroyed in a January explosion.
“Tanks were completely melted down,” a state inspector noted in a field report.
The cause is unclear, though it was not lightning, said Randy Juhlin, general manager and vice president of operations for White Owl. Nevertheless, the company rebuilt the site with incidents like lightning in mind.
White Owl in the future plans to use only steel, which helps dissipate static and is easier to ground than fiberglass.
“We looked at ways to reduce risk, and one of the ways was to use steel tanks,” he said.
But steel comes with a higher price tag. Juhlin estimates White Owl’s steel tanks cost 20% more than fiberglass ones.
White Owl also has lightning rods atop its facilities, as do some other saltwater disposal sites in the Bakken. Jappe said sometimes even with protection in place, sites still go up in flames.
Companies let the state Department of Mineral Resources know of any lightning protection plans when they construct new facilities, spokeswoman Katie Haarsager said. Nearly 500 saltwater disposal wells are active statewide. The agency issues permits for the wells, and facilities must comply with setback and other safety regulations.
But the state does not mandate lightning protection or coated steel tanks.
"It hasn't been something that has been added because many do have some type of preventative measures put in place," she said.
The department wants to give companies freedom to install new, better technology when it emerges, she said.
Jappe has another idea to alleviate danger to people nearby, as some incidents have occurred within a half mile of residents. She suggests limiting the number of fiberglass tanks at a well to four. Some sites have a dozen or more tanks.
Jeff Thompson, hazardous chemical officer with the North Dakota Department of Emergency Services, said he sees how a limit could help. But he also anticipates that could result in some unintended consequences.
“If we tell them only four tanks to a spot, are there just going to be small tank farms every quarter mile?” he said.
Like Jappe, Thompson has firsthand experience with lightning in the oil patch. He’s a member of the Dickinson Rural Fire Department. Incidents at saltwater disposal sites can be taxing on some small fire departments that frequently respond to them, he said.
Thompson has kept tabs on lightning and saltwater disposal sites the past few years and said it’s challenging to figure out the best solution to prevent damage at the sites. Any sound recommendations — or even potential regulations — require a lot more study, he said.
The issue might receive greater attention if fires resulted in more injuries, he said. The sites are not always manned.
From his research so far, it doesn't appear that oilfield infrastructure — like saltwater disposal sites — causes more lightning.
But there are a lot of oil patch facilities in the western part of the state that did not exist prior to the shale boom taking off a decade ago.
“We just have more targets out there,” he said.
Thompson pointed to one promising venue for addressing the issue: quarterly “neutral ground” meetings in which state officials and companies talk about safety issues in the Bakken.
Lightning has come up during past meetings. State officials several years ago recommended that companies split off small pipelines that connect between tanks to prevent fires from spreading.
“They used to vent saltwater and crude on one vent line,” Thompson said. “That allows fire to jump from tank to tank very easily.”
Some companies made the change, though Thompson said he’s not seen data showing whether it’s succeeded in preventing damage.
Meanwhile, Jappe’s hoping more companies take after White Owl.
She wants them to give greater consideration to lightning as they go about disposing the oil industry’s salty wastewater.
“I’m not out to tell people not to build saltwater disposal sites,” she said. “If somebody is going to come in to build a saltwater disposal, I’d like them to know what’s happened and what the trend is here."