Oil and gas producers are exempt from a federal environmental law designed to prevent industrial waste injection wells from triggering earthquakes.
When other industries inject their hazardous waste underground, they use wells tested to ensure they won't unleash quakes. Since oil and gas drillers are exempt from key provisions of federal hazardous waste law, they are also exempt from the earthquake prevention rules when they inject wastewater from hydraulic fracturing.
Man-made earthquakes are rare. Still, there are more earthquakes linked to injection of oil and gas waste than there are documented cases of drinking-water contamination linked to hydraulic fracturing.
And companies will likely be drilling a lot more underground injection wells to handle wastewater from the thousands of new oil and gas wells being drilled around the country.
"The problem is that there are a growing number of areas where they're doing injection," said seismologist Steve Horton, who linked a "swarm" of small earthquakes in Arkansas to oil and gas waste injection. "No one's actually providing any guidelines for how to avoid these problems."
Environmentalists say the earthquake exemption is just another example of the dangers of creating loopholes in environmental laws for oil and gas producers. They point to quakes last year in Arkansas and Ohio as evidence of the dangers.
"These incidents are yet another example of how the oil and gas industry gets special treatment when it comes to our bedrock environmental laws," said Briana Mordick, oil and gas science fellow at the Natural Resources Defense Council.
NRDC has asked U.S. EPA to end the hazardous-waste exemption for drilling companies, though its focus hasn't been on earthquakes. NRDC wants tougher regulation of deep injection of oil and gas production waste all the way around.
But Lee Fuller of the Independent Petroleum Association of America says the small number of earthquakes linked to the thousands of oil and gas disposal wells do not show a systemic problem requiring an overhaul of federal rules. Applying hazardous waste laws to domestic oil and gas drilling, he said, would dramatically increase costs for the industry.
"There's indications in some cases that some seismic events may have been related," said Fuller, IPAA's vice president of government relations. "That doesn't remotely suggest that the system is failing."
States can adopt stricter regulations on injection wells, as Ohio is doing for future drilling after linking an underground injection well to a series of earthquakes near Youngstown (Greenwire, March 9). Other states have not followed suit.
"It's one of those things that is just now being looked at," said Mike Nickolaus, special projects director at the Ground Water Protection Council, an association of state water regulators.
EPA has a team developing a series of recommendations to suggest to state regulators on earthquakes. The team started work last June and says it hopes the recommendations will help in "managing or minimizing" earthquakes triggered by oil and gas waste injection wells.
The agency, under fire on Capitol Hill from lawmakers concerned about over-regulation, had originally set out to draft recommendations to "avoid" earthquakes caused by oil and gas injection wells (EnergyWire, March 15).
In addition, the National Academy of Sciences is studying how several forms of energy production trigger earthquakes, an effort spurred by the concern of Sen. Jeff Bingaman (D-N.M.) that earthquakes could rattle public confidence in the country's growing energy industry (Greenwire, Jan. 5).
'Induced seismicity' isn't new
Oil and gas wells are grouped into "Class II" by EPA's underground injection control (UIC) program. Hazardous waste wells are considered part of "Class I."
Nationally, EPA records show there are about 150,000 Class II injection wells, although many of those are for "enhanced oil recovery" rather than waste disposal. Underground injection is also used to dispose of radioactive waste, hazardous waste and mining fluids. There are about 500,000 other types of injection wells that dispose of nonhazardous waste.
Geologists have known for years that deep injection of industrial waste can lubricate faults, unleashing earthquakes. One of the most famous instances of man-made earthquakes, or "induced seismicity," occurred in the late 1960s at the Rocky Mountain Arsenal near Denver, where the Army manufactured chemical weapons.
A Class I well was linked to an earthquake in 1987 in Ashtabula, Ohio. Last year, 60 miles due south, a series of earthquakes started near a Class II underground injection well in Youngstown, culminating in a magnitude-4.0 temblor on New Year's Day.
Months before that, underground injection triggered a "swarm" of small earthquakes in Arkansas. No injuries were reported from the earthquakes in Ohio and Arkansas. Horton, the seismologist, said that when he testified before the Arkansas Oil and Gas Commission in July, he was not asked whether injection triggered the temblors. Since then the research scientist at the Center for Earthquake Research and Information at the University of Memphis has published a paper saying injection was the cause.
When Congress passed the nation's federal hazardous waste laws in the 1970s as part of the Resource Conservation and Recovery Act (RCRA), it kicked to EPA the question of whether oil and gas production waste should be treated as hazardous. During the Reagan administration, the agency determined that it shouldn't be.
Since the requirement to test injection wells for the likelihood of earthquakes derives from those hazardous waste laws, oil and gas production is exempt.
The Ohio and Arkansas earthquakes have not been tied to the specific drilling practice of hydraulic fracturing. But hydraulic fracturing creates the millions of gallons of wastewater that drillers dispose of, usually by injecting it underground.
A prominent Department of Energy scientist said at a January forum in Washington that it should be relatively simple to check state geological maps to avoid drilling injection wells near faults (E&ENews PM, Jan. 26).
"A little bit of due diligence with existing technology can prevent this," said Julio Friedmann, director of the Carbon Management Program at the Lawrence Livermore National Laboratory. "You can do this on your iPad."
But geologists familiar with Arkansas and Ohio say such maps might not have tipped regulators and operators to the faults that were eventually triggered.
"Not all faults are mapped," said Ohio State University geologist Scott Bair. "Not all companies have the money to look that deeply. No one goes down there for mucks and grins."
Ohio officials said they had no indication of any seismic issues near the Youngstown well before it was drilled. Under the state's new rules, injection well drillers will have to provide more geological information.
Horton said the Arkansas fault he linked to injection hadn't been mapped. He said it could have been found, but perhaps not by routine surveys.
"I don't necessarily think they could have found it," Horton said.