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By Alan Kovski
Nov. 14 — The hot growth of oil development in the Bakken Shale region of North Dakota cooled off with the decline in oil prices during 2015 and early 2016. In the current breathing space, lessons from the environmental problems during that time are now shaping regulations and industry practices.
Brine spills have especially captured attention. When salty produced water comes to the surface with crude oil, it is separated from the oil and then pipelined or trucked separately for disposal—and sometimes spilled. Spilled brine can ruin soil chemistry and severely alter groundwater.
“There’s this exponential increase in brine spills,” Max Post van der Burg, a U.S. Geological Survey research ecologist based in Jamestown, N.D., told Bloomberg BNA about the Bakken Shale development.
In 2014, approximately 71,000 barrels of brine were spilled in 855 incidents associated with oil and gas development in North Dakota, according to the Energy & Environmental Research Center of the University of North Dakota. This compares to 6,200 barrels of brine spilled in 2001.
There also has been an exponential increase in oil production since about 2008 from the Bakken and from the Three Forks Shale, below the Bakken. Many substantial producers operate in the area, led by Continental Resources Inc., Whiting Petroleum Corp., Hess Corp. and EOG Resources Inc.
Amid the development, prairie grasslands survive but have been dotted with drilling and production sites interconnected by roads and buried pipelines. The region’s “prairie potholes,” a type of wetland, also survive among the production sites and provide important habitat for migrating birds, though some have been contaminated by brine or oil.
Brine from the Bakken Shale is roughly 10 times as saline as seawater and about three times as saline as typical produced water in U.S. oil and gas fields, according to data gathered by the U.S. Geological Survey.
The salty water causes clay particles in the soil to swell up enough to squeeze shut the pores that allow water to seep through. Brine also reduces the osmotic pressure that helps plants take in water through roots. Both factors mean that plants will die from lack of water in salty soil.
And the salt lingers. While oil is degraded by bacteria, salt remains until diluted or washed away by enough fresh water—or until someone removes the soil or saline water as part of a remediation program.
Asked if brine spills can be more of a problem than oil spills, Cody VanderBusch, a Bismarck-based reclamation specialist for the North Dakota Industrial Commission, said, “Yes, brine can be more of a challenge especially over time. Brine spills destroy the soil and make plants unable to grow. Removal of the impacted soil in most cases is the best option for remediation.”
When one company’s brine pipeline leaked recently, the company estimated it would take five to 10 years to remediate the contamination of a wetland, groundwater and soil.
When the brine gets into a subsurface water resource, “you have to invest a lot of money in flushing the aquifer,” Post van der Burg said.
The combined issues of oil and brine spills from pipelines concerned the North Dakota state legislature enough that the lawmakers commissioned a university research center to study the subject, and some of the results are shaping new regulations.
The December 2015 report by the University of North Dakota’s Energy & Environmental Research Center indicated brine spills in the state do not appear to be out of line with what could be expected in fast-growth oil production areas in other states, despite the attention given to spills in the Bakken.
“In essence, a very small number of high-profile, large pipeline spills have greatly skewed the trend lines,” the report said.
The report focused especially on gathering pipelines. These networks of piping systems are regulated by the state rather than the federal government. Networks of gathering lines move oil and produced water to separators, after which some lines move produced water to injection disposal wells while other lines move oil to larger, long-distance transmission lines headed toward refineries.
More than 10,000 miles of gathering pipelines were put into service in North Dakota during the five-year period from 2011 through 2015, according to state data. An Oasis Petroleum Inc. manager said his company alone probably had 500 wells hooked up to gathering lines. A line moving brine from an oil production site to a disposal injection well would typically be less than 10 miles long, he said.
The study recommended a regulatory regime of pipeline inspections, better construction standards, better worker training and state access to failure analyses. State regulations—some effective Oct. 1, some likely effective Jan. 1—address several of the recommendations, said Kevin Connors, pipeline program supervisor of the North Dakota Industrial Commission.
The new regulations set minimum standards for constructing underground gathering lines for both crude oil and produced water. The standards address pipeline materials, design, proper training for construction crews, pipeline handling, trench construction and trench backfilling.
All newly constructed crude oil and produced water underground gathering pipelines must be inspected by third-party independent inspectors to ensure they are installed properly. Drilling pads also must have berms to reduce the risk that spills will escape off the site.
Failure analyses are a tougher regulatory issue.
“In order for this recommendation to come to fruition, the North Dakota state legislature would have to expand the Industrial Commission’s authority to allow the commission to be involved in pipeline failure analyses and manage the information obtained as confidential,” Connors told Bloomberg BNA.
Incident reports do not shed enough light on the causes of pipeline failures, according to the University of North Dakota report.
“Anecdotal evidence suggests line strikes, poor workmanship, and lack of inspection are the root cause of many gathering line leaks,” the report said. “However, analysis of spill statistics data could not corroborate this statement. While each company performs its own failure analysis when a spill occurs, companies are disincentivized to share that information because of the litigious environment in which they operate.”
“Line strikes” refer to the all-too-common problem of someone operating equipment such as a backhoe without realizing there is a pipeline below.
In North Dakota, much of the attention seems to have stemmed from “legacy spill sites” contaminated in the 1980s in a much earlier phase of oil exploration, said Kari Cutting, vice president of the Bismarck-based North Dakota Petroleum Council, an industry group.
Pete Hanebutt, director of public policy for the North Dakota Farm Bureau, agreed.
“There were some brine problems in the past that were way more serious than they are now,” Hanebutt told Bloomberg BNA.
His group’s members are the farmers who have to worry about a spill affecting their land and crops. It is not the big concern it once was, thanks to regulations and better industry technologies and practices, Hanebutt said.
“We keep an eye on it,” he said, expressing a hope that compliance and enforcement will be adequate.
Reporting requirements may give an exaggerated impression of how much trouble North Dakota is having with spills. The state’s threshold for spill reporting is among the lowest of comparable states, the University of North Dakota report said.
“North Dakota requires reporting of all spills off of the well pad, regardless of size,” the report said.
The report’s author was unable to find any publicly available brine spill data for Texas, the state with the most oil production.
A North Dakota Petroleum Council task force has been looking at brine issues and in September completed a remediation resource manual for dealing with brine spills.
The American Petroleum Institute issued a guidance document in 1997 on remediating salt-affected soils at oil and gas production sites a decade before the Bakken Shale development took off. Exceptionally high salinity occurs in some other places, such as central Oklahoma and northwestern Louisiana.
Efforts are made to improve not only infrastructure construction and operation but also remediation technologies and techniques. The oil industry in North Dakota has worked with university scientists and specialists at the state departments of health and mineral resources to improve spill response, Cutting said.
Removal of contaminated soil may be the most common and effective remediation, but companies also can try pumping out saltwater, flushing with freshwater and amend soil with calcium or organic materials.
One of the more recent techniques being explored is electrokinetics, the sinking of electrodes into soil and using an electrical current to get salt ions to flow through groundwater to the electrodes for removal from the soil. The dominant salt in the Bakken produced water is sodium chloride.
Brine remains only one of the many potential environmental concerns connected to oil and gas development. The cumulative environmental impacts of the Bakken Shale development will be the subject of a U.S. Geological Survey report currently in peer review targeted for release by the end of the year.
The USGS report was requested by the Bakken Federal Executive Group, which includes representatives of the U.S. Fish and Wildlife Service, the Bureau of Land Management, the National Park Service, the Bureau of Indian Affairs and the U.S. Forest Service.
The report will include information on air quality and spill rates and will pull together information on groundwater, surface water, wildlife, ecosystems and other subjects from many contributing authors—with the caveat that there is not as much data as an ecologist would like.
“The thing that has really jumped out is that there isn’t a lot of information,” Post van der Burg said. “There are a lot of gaps.”
To contact the reporter on this story: Alan Kovski in Washington at firstname.lastname@example.org
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Energy & Environmental Research Center Report on Gathering Pipelines is available at http://src.bna.com/jT5.
Copyright © 2016 The Bureau of National Affairs, Inc. All Rights Reserved.
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