A saltwater spill in Renville County initially reported more than two weeks ago as 200 barrels is larger and could have contaminated as much as 400,000 square feet of soil, the Bismarck Tribune has reported.
“We know it’s bigger, we know it’s impacting a very large area,” said Bill Suess, spill investigation program manager for the North Dakota Department of Environmental Quality.
Officials do not yet have an updated spill volume. The initial 200-barrel amount reported by operator Cobra Oil & Gas on Jan. 13 is equivalent to 8,400 gallons.
The fluid that spilled, commonly known as brine, is highly saturated saltwater that comes up alongside oil and gas at well sites. It’s typically injected back underground at disposal wells for permanent storage. When it spills and is not contained to a well pad, it can render farmland infertile.
The brine leaked from a pipeline and contaminated a field north of Sherwood near the Canadian border. A number of pipelines exist in the area, and it’s possible the leak could have come from more than one, Suess said.
Workers at the site are trying to determine the scope of the spill -- how far contamination has extended horizontally and vertically from the site of the leak, he said.
“This is an older pipeline that was probably leaking for a period of time,” he said. “We’ve got to find out exactly how far it’s gone.”
A summary of the incident maintained by the state says the contamination is 8 feet deep in some areas.
The landowner, Sherwood resident Allan Engh, said people involved in the cleanup of the site told him the brine could have contaminated as much as 400,000 square feet of soil, which is about 9 acres. Suess said that estimate could be accurate but the official number is not yet known.
So far, the reclamation effort has involved digging up the soil around the pipeline to expose part of the line, and crews have been hauling away brine and groundwater.
“It’s that initial scramble to contain as much as they can to keep it from spreading,” Suess said.
The weather poses some challenges to the reclamation effort. Suess said a rainy fall has saturated the ground, and he added that snowmelt also could pose problems in spring as there are sloughs in the area that collect water.
Engh said he leases the land to a farmer, who could face problems seeding if the spill has not been reclaimed by mid-April. He said state inspectors and entities involved in the cleanup have done “a pretty good job keeping me posted with what’s going on.”
Cobra Oil and Gas did not immediately respond to a request for comment.
Oil development has occurred for decades in the north-central part of the state in Renville County and the surrounding area, and saltwater contamination has plagued the region for many years.