Why a natural gas storage climate ‘disaster’ could happen again

This story was initially revealed by Floodlight, a non-profit newsroom that investigates the highly effective pursuits stalling local weather motion.

On a November afternoon in 2022, a 57-year previous effectively tapped into an underground pure gasoline storage reservoir in western Pennsylvania began leaking, quick sufficient that individuals a number of miles away heard a loud, jet engine-like noise. 

By the point the leak was stopped practically two weeks later, roughly 16,000 metric tons of methane had escaped into the environment, the equal of greater than the annual greenhouse gasoline emissions from 300,000 gas-powered automobiles.

The blowout of a effectively on the Rager Mountain gasoline storage subject was the worst methane leak from underground storage since Aliso Canyon in California in 2015. That incident pressured hundreds of individuals from their houses and sickened a lot of them, taking 4 months to comprise. In 2021, 35,000 plaintiffs in a single class-action lawsuit had been awarded as much as $1.5 billion in damages. 

Whereas not as massive or imminently harmful to residents, the Rager Mountain leak was a “catastrophe,” in response to one Pennsylvania regulator. Bloomberg labeled it the USA’s worst local weather catastrophe that 12 months. 

The pure gasoline that leaked methane in Pennsylvania and California will not be saved in tanks however in large underground geological formations accessed by a number of wells. There are about 400 such storage fields throughout 32 states.

In keeping with a brand new report, there are hundreds extra potential alternatives for the same scenario throughout the nation. The brand new evaluation of information collected by federal regulators suggests there are as many as 11,446 storage wells within the nation with the identical key danger because the wells that failed at Rager Mountain and Aliso Canyon: They’ve solely a single barrier to failure.

“That inhabitants is so much bigger than we had estimated, or different researchers had estimated with state [data],” says Greg Lackey, an creator on the research and researcher on the Division of Power’s Nationwide Power Know-how Laboratory. 

All however one in every of Pennsylvania’s 49 gasoline storage fields has not less than one potential single level of failure effectively, researchers discovered.

Pure gasoline is primarily made up of methane, a greenhouse gasoline 80 occasions extra highly effective than carbon dioxide within the short-term. Methane leaks from oil and gasoline infrastructure are underneath growing scrutiny in the USA and worldwide, as stopping them represents a comparatively low-cost and efficient solution to forestall greenhouse gasoline emissions, the first trigger of worldwide warming.

Leaks from gasoline storage are just one a part of the business’s methane downside. Such amenities are also liable to dramatic blowouts which can be onerous to manage as a result of they’re related to massive, pressurized reservoirs of gasoline. 

New guidelines, charges intention to chop methane leaks

Rules put in place on gasoline storage post-Aliso Canyon are nonetheless rolling out, together with a requirement for baseline danger assessments on all wells by 2027. New EPA guidelines on methane leaks and restore and a deliberate federal charge on “waste” methane would affect gasoline storage as effectively. 

The charge, which continues to be being finalized, would drive corporations to finally pay as much as $1,500 per metric ton of methane in extra of the equal of 25,000 metric tons of carbon dioxide, a threshold the Rager Mountain leak meets virtually 20 occasions over. Business teams have pushed again towards the charge, arguing it could hurt smaller oil and gasoline corporations and discourage oil and gasoline manufacturing total.

Many of those wells are decades-old and never initially designed for storage. They’ve gone by way of the stresses of repeated cycles of injecting and withdrawing gasoline. Some, like Rager Mountain, are in comparatively rural, sparsely-populated areas, however others are near neighborhoods in Pennsylvania, Ohio and California. 

The Rager Mountain leak was attributable to a break beneath floor in a single effectively’s casing — the barrier between the place pressurized gasoline flows and the geology round it. The effectively had develop into closely corroded from publicity to water, air and natural matter by way of an open valve, in response to an third-party evaluation submitted to regulators and obtained by way of a public information request.  

“They in all probability didn’t understand it, however they had been creating an optimum case for corrosion,” says Dan Arthur, president of the engineering and technical providers agency ALL Consulting, who reviewed the evaluation. 

Arthur says older wells in storage fields haven’t been given “as a lot significance” as they need to be, and operators want to verify they’re totally addressing effectively integrity.

“Age is a danger issue that it’s important to think about, nevertheless it additionally relies on how you’re caring for the effectively,” he says. Redundant obstacles cut back the danger of methane escaping if the effectively casing fails, Arthur and Lackey say.

Minimal federal security requirements on underground storage fields had been set lower than a decade in the past within the aftermath of the Aliso Canyon leak. One of many federal companies in control of regulating gasoline storage websites, the Pipeline and Hazardous Supplies Security Administration (PHMSA), solely started gathering common knowledge on underground storage fields in 2017.

Extra knowledge wanted to determine riskiest wells

The variety of wells with doubtlessly just one barrier was thrice bigger than beforehand estimated earlier than the PHMSA knowledge grew to become out there, Lackey says. This “single level of failure” design featured in each Rager Mountain and Aliso Canyon blowouts is current in as many as 64 p.c of all gasoline storage wells in the USA, his analysis discovered.

However the knowledge reported to PHMSA will not be sufficient to verify what number of of those wells even have a single level of failure that may flag wells on the highest danger of one other blowout, Lackey says. Researchers would wish extra details about every effectively’s design and building, he says.

“What you don’t get perception into is what number of different casings there are, or the place the areas of cement are,” Lackey says, describing further obstacles that may decrease the danger.

Rager Mountain’s proprietor and operator, Equitrans, had its personal danger rating of storage wells, in response to the third-party evaluation. Whereas Rager is the corporate’s largest subject in Pennsylvania, its wells weren’t the very best ranked within the firm’s personal danger administration plan — others had been larger up the listing due to their proximity to residential areas.

Each Peoples Pure Gasoline, the earlier proprietor of the sector, and Equitrans “acknowledged that corrosion was a problem,” so the businesses used probes, often known as “logs,” to look at the integrity of the effectively casings. However, the evaluation famous, “Such a technique depends on the logging being fairly correct.”

A 2016 check of the casing wall of the effectively that finally failed underestimated its corrosion, the report says. When Equitrans reran the check after the blowout utilizing an up to date algorithm, it confirmed much more corrosion.


Within the wake of the Rager Mountain blowout, Pennsylvania’s Division of Environmental Safety, stated it was contemplating a  “high to backside assessment” of the state’s gasoline storage business. Pennsylvania is one in every of a handful of states which have their very own rules protecting gasoline storage. 

“Every part is on the desk for consideration by way of ensuring this business is regulated appropriately and the general public is protected and the surroundings is protected against potential incidents like this occurring once more,” stated Kurt Klapkowski, performing deputy secretary for DEP’s Oil and Gasoline Administration workplace, a month after the incident.

‘An enormous battery system’

However after a profitable effort by Equitrans to maneuver the majority of the incident investigation to federal regulators, DEP seems unsure or unable to maneuver ahead with such a assessment. Klapkowski instructed the company’s Oil and Gasoline board in September that regulators had been “attempting to determine the place our jurisdiction ends or is likely to be preempted by the federal authorities.”  

Pennsylvania DEP’s investigation into floor and groundwater contamination at Rager Mountain is ongoing, the company stated in an emailed assertion, and it “stays dedicated to its objective of inspecting storage subject wells on an annual foundation no matter danger.” 

Wells are assessed by way of floor inspections and data reported by operators, DEP added, utilizing a number of components to prioritize wells for inspection, together with the potential environmental affect and chance of failure, in addition to proximity to inhabitants.

Equitrans has taken a number of steps to cut back danger in its storage fields, spokesperson Natalie Cox stated in an emailed assertion. They embrace reprocessing older effectively exams, working further exams on one other 100 wells in 2023, and altering its necessities for when so as to add protecting gel to cut back corrosion. The corporate didn’t reply questions on whether or not these exams led to any effectively replacements. 

Lackey’s research additionally discovered that nationally, whereas most leaks from gasoline storage had been related with accidents or effectively enchancment tasks often known as workovers, leaks from corrosion launched a a lot bigger quantity of methane.

“If it’s a valve or one thing that’s damaged off on the wellhead, that is likely to be simpler to comprise, fairly than one thing downhole that may be uncovered to larger pressures throughout the effectively,” he says. “Throughout workovers you will have programs in place to comprise the effectively … whereas with corrosion, that’s one thing occurring silently within the background.”

Whereas a 2016 authorities activity drive really helpful phasing out single level of failure of wells, finally the federal minimal requirements solely required operators to deal with them by way of submitting risk-management plans to federal regulators — plans that aren’t public. 

The discharge of gasoline from Rager Mountain in November 2022 represented about 15 p.c of the sector’s working storage quantity. Underground storage fields act as “an enormous battery system,” says Drew Michanowicz, a researcher who has studied their proximity to residential areas. 

Main leaks from storage not solely launch big volumes of greenhouse gases but additionally cut back reliability in areas the place pure gasoline dominates house heating and electrical energy manufacturing, Michanowicz says.

The federal leak investigation at Rager Mountain stays open not less than till regulators assessment work on fixing three quickly plugged wells within the subject, probably within the spring. However Rager Mountain is in any other case working. In October, with PHMSA’s approval, Equitrans started injecting gasoline into the sector for the winter. 

This story was produced with help from the Fund for Investigative Journalism.