Renewable natural gas plant operator at Keystone Landfill begins test drilling for underground carbon dioxide storage

Yahoo

13-02-2025

A renewable natural gas plant operator at the Keystone Sanitary Landfill has the green light to drill a nearly 3-mile-deep well in Throop this week as it looks to permanently store carbon dioxide deep underground.
The state Department of Environmental Protection gave Archaea Energy permission to start work on an exploratory drilling operation in Throop to determine the feasibility of carbon sequestration, DEP spokeswoman Colleen Connolly said in an email. Drilling for the well, which is permitted to be about 15,000 feet deep, was set to begin Tuesday, Connolly said.
The exploratory well will be across the Casey Highway from the Keystone Sanitary Landfill, roughly 2,100 feet east of the highway and about half a mile south of Marshwood Road, according to GPS coordinates posted on a project sign at the entrance of an access road along Marshwood Road. Theta Land Corp. owns the property; landfill owner Louis DeNaples owns Theta Land Corp. through the defunct Pennsylvania Gas and Water Co., according to the landfill's April 2024 operating permit renewal application with the DEP. PGW owns Theta, and DeNaples is the president of PGW with a 100% ownership stake, according to the permit application.
The entrance to Archaea Energy's exploratory well site off of Marshwood Road in Throop on Tuesday, Feb. 11, 2025. (Jim Lockwood / Staff Photo)
In a statement late Wednesday afternoon, Archaea Energy said it is in the early stages of evaluating the potential of implementing a carbon capture and sequestration project in conjunction with its renewable natural gas project aiming to capture and permanently store carbon dioxide emissions.
'To thoroughly assess the viability of this project, it is essential for us to drill a site characterization well to gather data, perform analysis, and conduct modeling,' the Houston-based company said. 'That process commenced this week. These steps are critical in determining whether the appropriate conditions exist to ensure the secure, long-term storage of CO2. Prior to and throughout the drilling, we have been working with state regulators, Throop Borough officials, residents, project neighbors and stakeholders to inform them of the project and obtain the necessary permits and approvals required to proceed with the project.'
The drilling of the well is regulated by DEP's Oil and Gas Program, which has already been monitoring the construction of access roads and well pads, Connolly said.
Archaea Energy, owned by London-based BP, is the parent company of the Assai Energy renewable natural gas plant in the Throop section of the landfill near Marshwood Road. The Assai plant became fully operational in December 2021 and pipes in gas produced by decomposing garbage at the Keystone Sanitary Landfill in Dunmore and Throop and the Alliance Landfill in Taylor and Ransom Twp., processing the landfill gas into pipeline-quality natural gas. The renewable natural gas process involves removing carbon dioxide and other contaminants from the landfill gas until it is more than 94% methane.
Assai currently burns off the excess carbon dioxide into the atmosphere, but in 2023, the renewable natural gas producer announced its intent to explore drilling deep underground and injecting the greenhouse gas into the rock formations for permanent storage.
Carbon dioxide is the primary greenhouse gas emitted through human activities, accounting for 80% of all greenhouse gas emissions in the country from human activities in 2022, according to the U.S. Environmental Protection Agency.
The U.S. Department of Energy calls the storage of carbon dioxide 'increasingly important because these emissions are warming the Earth's climate in ways not seen in millions of years.'
Geologic carbon sequestration — the type Archaea is looking to do — entails compressing the carbon dioxide gas so much that it behaves like a liquid, and then injecting it into porous rock formations deep underground where it becomes physically trapped in the pore spaces, dissolves in the liquid within the rock formations and eventually reacts to form stable minerals, according to the DOE.
Archaea Energy hosted a public information session about the project in December 2023 at the Throop Civic Center. An Archaea official at the time touted the project as making a 'significant improvement to air quality.'
Retired DEP geologist John Mellow, an Archbald resident and member of the environmental nonprofit Sierra Club's Northeastern Pennsylvania Group, noted potential concerns depending on the depth of the injections. If there was coal mining in the area, which would've been about 400 feet at its deepest, Mellow raised concerns about the possibility of carbon dioxide escaping into the voids, which could lead it to homes or businesses, though he believes the coal outcrops likely ended before the work area, lowering that concern.
'Can they seal off the fractured and coal voids that are still existing?' Mellow said.
If the the injections were closer to 15,000 feet, he questioned whether the bedrock formation would be too tight to contain the carbon dioxide, or if it would have to be fracked to open it up.
Mellow encouraged Archaea to hold another public information session.
During its first session more than a year ago, company representatives estimated spending two to three months drilling and taking samples and measurements. Drilling the exploratory well would allow them to determine how porous and permeable the underground rock formation is, and if the results were not favorable and Archaea could not safely inject the carbon dioxide, they would not do it, the company said at the time.
If the project moves forward, the carbon sequestration will be regulated by the EPA, Connolly said.