Unreliable reporting

Ingraffea noted that their calculations are likely on the low end of true methane emissions from oil and gas well leaks in Pennsylvania.

There are around 132,000 operating oil and gas wells in the state, but fewer than half of those reported data on methane leaks to the PA DEP as required. Of the some 60,000 wells that submitted reports, about half of those didn't actually include any data, citing various reasons they couldn't take measurements on methane leaks (like inability to access the well site). The study also only looked at data from wells that are actively producing—it didn't account for methane leaks from abandoned wells or wells that were still being actively drilled or fracked (and not yet producing).

Shader said that the wells missing data are conventional wells, not fracking wells, and include things like home-use wells and wells from small operators. "DEP often receives data from these operators on paper, and it must be entered manually, which can cause delays in making the data available electronically," he said, "however, DEP has and will continue to take enforcement actions against operators that do not comply with the reporting requirements."

The Pennsylvania Independent Oil & Gas Association (PIOGA) declined to comment on whether the industry is working to resolve these issues with reporting.

The researchers also noted some major issues with the reliability of the data. For example, some wells that reported large quantities of methane leaks for several years in a row would suddenly report none after being purchased by a different operator the following year. One likely reason for this is a lack of consistency in testing techniques, Ingraffea said. Operators aren't all required to use the same testing equipment or methods.

"Not only is much of the data unreliable," he said, "but I will go on record as saying that some of the data being reported to the state is downright fraudulent."

There's also no minimum reporting requirement, so some operators would note that the emissions were too low to report, but the researchers have no way of knowing what threshold they used to determine that. All of these factors likely mean the reported emissions the researchers analyzed are underestimates.

Ingraffea said there should be a requirement to measure and report on methane leaks in a consistent manner and "super emitters" should be targeted and required to fix leaking equipment.

"Most wells aren't leaking," he said. "If they're operating correctly, they shouldn't leak. Maybe just 10 percent of all unconventional wells are leaking, for example, but they're not all leaking the same amount, either. Some leak just a little, and some, the super emitters, leak like sieves. DEP should require those to be fixed."

Many of those super emitters are coalbed methane wells, most of which are located in the Southwestern part of the state where a majority of the state's fracking also occurs.

"DEP is also concerned with these 'super emitters,' Shader said, "and is exploring ways to identify them, as well as being interested in suggestions for identifying them."

He added that DEP is aware that methane leaks are also a problem at abandoned wells (which were not looked at as part of the Cornell study), but that the agency "has very few resources to devote to plugging," and hopes initiatives like Governor Wolf's Restore PA initiative, which would provide funding for critical state infrastructure including plugging abandoned wells, will help address the leaks.

Lack of regulations, lack of accounting

In December, Pennsylvania's Environmental Quality Board voted in favor of a new set of regulations aimed at reducing emissions of volatile organic compounds (VOC) like benzene, toluene, and other chemicals linked to cancer and other health effects from fracking sites. The rule is slated to be enacted following a 60-day public comment period, which the PA DEP said is expected to occur sometime this year, "likely next month."

Governor Tom Wolf's office, which drafted the regulations, claimed the new rule would also indirectly reduce methane emissions by more than 75,000 tons (about 68 gigagrams) per year, but environmental advocates expressed frustration that the rule doesn't directly address methane leaks.

"We have known for years that PA DEP's emissions inventory, which relies on industry-reported data, significantly understates the actual emissions coming from the Pennsylvania oil and gas sector," Joseph Otis Minott, executive director and chief counsel for Philadelphia-based advocacy group Clean Air Council, told EHN. "We are encouraged to see that DEP estimates its proposed existing source rule will reduce over 75,600 [tons per year] of methane emissions and would respectfully urge the Department to open a public comment period on the proposal as soon as possible."

Ingraffea said there have been "hundreds of reports and papers looking at methane emissions published since my first paper came out in 2011...and the scientific consensus is that what EPA is reporting to all of us, and to Congress, and to the President significantly underestimates the actual methane emissions from the oil and gas industry."

Banner photo: Residents of Southwestern Pennsylvania tour a producing fracking well pad. (Credit: Kristina Marusic/EHN)

Editor's note: The story has been updated to clarify Pennsylvania's annual methane leak reporting requirements.