How to tell if fracking fluid has leaked from a well? A local company is trying a new technology to trace potential leaks.
By Marisa Grant
When states across America open themselves up to the exploration of oil and natural gas, it doesn’t always go smoothly.
In March 2013, residents of Mayflower, Arkansas had to evacuate their homes when Exxon Mobil’s Pegasus pipeline spilled an estimated five to seven thousand barrels of oil into local streets and waterways.
This past September, North Dakota suffered from one of the biggest hydraulic fracturing accidents in history when 20,600 barrels of oil spilled and went undetected for weeks. According to a report by the Associated Press, North Dakota has suffered from more than 300 oil spills over the past two years and not one was reported to the public, prompting the state to create a website to track the spills.
The question of how to identify and report spills that might be occurring below ground and assign blame remains a vexing one. And as North Carolina moves forward in its discussions of the future of hydraulic fracturing in the state, the lack of disclosure and questions over liability and possible contamination have landowners and environmentalists worried.
“When you tamper with a precious natural resource, which water is,” said Kevin Foy, a professor of environmental law at North Carolina Central University School of Law, “the burden shouldn’t be on proving that pumping millions of gallons of pressurized chemicals into holes in the ground causes water pollution. The question should be, what scientific evidence is there that it doesn’t?”
Sense of urgency
Hydraulic fracturing – more commonly known as fracking – is the process of drilling for oil and natural gas underneath the ground. In order to release gas that is then collected in underground wells, water and other chemicals – including sand, salt and citric acid – are pumped into the earth at highly pressurized levels to break up shale rock formations, thereby releasing natural gas.
But gases and oil don’t move in convenient, straight or predictable patterns underground, and the potential exists that fracking chemicals or the gases released by the process can get into groundwater, wells and aquifers, contaminating them.
As the state takes steps toward permitting fracking, North Carolina lawmakers must contemplate the issues surrounding it with some urgency.
On March 1, 2015, the moratorium on issuing permits for horizontal drilling and fracking, established by state Senate Bill 820, may end if the General Assembly votes to legalize fracking in North Carolina.
Whether fracking is safe or has the potential to contaminate groundwater have been issues debated by the N.C. Mining and Energy Commission (MEC). The MEC, which formed upon the passage of SB 820 in July 2012, has held monthly meetings to discuss the implications of fracking in North Carolina and to establish regulations and standards on which the General Assembly will vote.
Recently, the MEC discussed what implications fracking might have on the state’s water supply and how to determine liability in case of a spill. The commissioners have also discussed whether North Carolina has the technology to detect chemical spills.
The MEC’s chairman, Jim Womack, said that regardless of what other states are doing, the MEC will continue to seek out emerging technologies to determine if they’re a good fit for North Carolina, and that “risk mitigation” is a major concern for the commission.
“With proper regulation, which includes baseline testing and subsequent testing, and proper punishment of misbehavior, fracking is manageable,” said MEC member Vik Rao, who heads the commission’s Water and Waste Management Committee.
The fear of water contamination and determining who would be at fault in case of a spill has led the MEC to discuss the usage of tracer technology. Tracers can be used to determine liability in case of a spill and whether the water supply has been contaminated.
Rao believes that the benefits of fracking in North Carolina will outweigh any possible negatives. “The risk is relatively low,” he said, “but the advantage is relatively high, because fracking displaces [the need for] coal and diesel.”
Rao also stressed the importance of regulation in the industry, saying that any company that mishandled a fracking site should suffer “severe penalties.”
He said he believes that tracer technology can help in that regard: “I want tracers to happen. It gives another option to possibly protect the public, but to identify the culprit.”
Enter BaseTrace, a startup company founded by graduates of Duke University’s Nicholas School of the Environment, which has developed a tracer technology with the ability to identify the liable party in the event of a spill.
The technology, which consists of applying drops of DNA strands to fracking fluid, leaves a chemical fingerprint on every batch of fracking fluid that goes into a well. It is essentially a tagging mechanism that leaves a “unique fluid so we can distinguish fracking fluid A from B,” said BaseTrace CEO Justine Chow.
No state is yet using DNA tracers in hydraulic fracturing. Several states, including Texas and Pennsylvania, use radioactive tracers, which BaseTrace CFO Jake Rudulph said are harder to handle and more expensive than DNA tracers.
“Radioactive tracers are used in oil and gas exploration purposes, but they are not yet used to tag contamination in order to determine what happens after a spill,” he said.
DNA tracers can be used in any well that contains fracking fluid; distance doesn’t factor into their accuracy. The tracer is added to the well before the fracking fluid is mixed. Because each well is distinguishable from the next, if the liquid in a well experiences a chemical change after fracking begins, there is proof that a leak has occurred.
Rudulph explained that tracers are the easiest first step in determining whether a spill has occurred because if fluid that contains a tracer migrates, the tracer should be detectable. Any liquid containing a tracer can help identify the well the liquid came from, and the company who set up that well, thus establishing liability for the spill.
Chow said that the tracers are designed to withstand the extreme pressure and temperature involved in fracking and that the technology remains effective throughout the extraction process, which can take anywhere from a few days to a few weeks.
BaseTrace has also tested tracers in ultraviolet light to simulate flowback fluid, and found that the DNA is still detectable after being exposed to the elements for up to two months.
Burden of proof
There’s much debate over the question of fracking and the contamination of drinking water, and how to address the potential.
A recent study by the Nicholas School of the Environment found that drinking water near shale gas wells appeared to be contaminated due to stray gases. The study, Increased Stray Gas Abundance in a Subset of Drinking Water Wells Near Marcellus Shale Gas Extraction, which involved testing more than 100 water samples from private wells in Pennsylvania, established that homes within one kilometer of a shale gas well had, on average, methane levels that were six times higher and ethane levels that were 23 times higher than homes farther away from the wells.
The Duke study emphasized how much of a factor distance from a gas well is when it comes to water contamination.
But over the past year, the MEC has discussed whether the baseline testing established in SB 820, which requires testing water wells within a 5,000-foot radius of oil and gas drilling sites before fracking takes place, should be reduced to 1,500 feet.
Baseline testing allows for the comparison of well water pre- and post-fracking to determine whether any contamination has occurred.
MEC member Charles Holbrook, who proposed shortening the distance of testing to 1,500 feet, said that the “5,000-foot radius in which water well sampling is to be required is arbitrary and excessive, and not based on the practices in any other state or industry standard.”
“There is not one creditably documented case, of which I am aware, of hydraulic fracturing operations resulting in the contamination of near-surface fresh-water resources,” he said.
Womack said that he has been encouraged by both radioactive and DNA technology and hopes that North Carolina can “encourage the industry to use tracer technology if we can reduce the range of water testing.”
But limiting water testing concerns many environmentalists.
“Although there is supposedly a lack of scientific consensus on whether fracking causes water pollution, that is merely shifting the burden,” said N.C Central’s Kevin Foy.
Foy said the burden of proof should be on those who want to move forward with fracking, not on opponents of the practice.
For now, the MEC will continue to debate regulations and determine what is required to protect the state from groundwater contamination.
But it will be up to the legislature to decide whether to impose limitations on fracking, and whether to require safeguards like tracers to minimize the potential damage fracking can cause.