A 200-barrel produced water spill that affected pastureland in McKenzie County will be remediated by digging out the soil and removing it, then backfilling and revegetating it.
The spill was reported to the North Dakota Department of Environmental Quality on Aug. 31 from a pipeline operated by Henry Hill Oil Services.
Bill Suess, spill investigation program manager for the Department of Environmental Quality, told the Williston Herald the cause of the spill is not yet known.
A phone call has been placed with the company to request further information about the spill’s cause. That call has not yet been returned.
Suess said he believes the spill volume the company reported is probably accurate.
“(The estimate) was based on the leak detection equipment,” he said, indicating that is also how the spill was discovered.
“There was no oil in the spill,” Suess added, referring to a media release sent out on Tuesday, Sept. 3, that characterized the spill as a mixture of oil and produced water.
Suess said while cleaning the spill up will probably take just a few weeks, monitoring will be a longer-term process.
“Two hundred barrels can go kind of deep,” he said. “So that might be a few weeks to get cleaned up, depending on the weather and everything else. Our follow up, on the other hand, will be a year or more, and at least into next spring.”
Suess said his program will return to the site in spring to see that the vegetation is establishing itself properly, and will monitor it for a time thereafter to ensure there are no further problems.
This is the second spill by Henry Hill Oil Company that has missed containment, Suess said, and the 38th spill overall since 2016. The other 36 spills were retained on the well pad.
The first spill that escaped containment happened in June 2016 and was caused by a faulty valve-piping connection.
Suess said someone from his program has been to that site recently, and recorded that vegetation is so far showing no signs of stress.
There was a note, however, that more followup on the site is needed, Suess said. He was not sure what the note referred to, but said he would look into it.
“(Henry Hill) has not had many spills offsite,” Suess said. “We are getting some phone calls from them looking for guidance, so they are obviously working to do everything right.”