Renewable natural gas plant at Keystone Sanitary Landfill fined for air pollution violations – Scranton Times-Tribune

Oct 24, 2024

A landfill gas processing plant in Throop at the Keystone Sanitary Landfill agreed to pay more than $70,000 in fines for air pollution violations.

The state Department of Environmental Protection executed a “consent assessment of civil penalty” against Assai Energy LLC totaling $72,937.50, with Throop eligible to receive 25% of the penalty, or $18,234.38, according to a letter Friday from DEP regional air program Manager Mark Wejkszner addressed to Throop solicitor and Borough Manager Louis Cimini.

“This penalty resolves documented air pollution violations,” Wejkszner wrote.

Assai Energy’s Senior Vice President of Operations Steven Boor and Vice President Donna Ward signed the Oct. 7 consent assessment, agreeing to pay the fine.

According to the DEP, Throop will be allowed to use the money for projects that eliminate or reduce air pollution, or for parks, recreation projects, trails or open space.

Assai Energy’s renewable natural gas plant, which is located inside the Keystone Sanitary Landfill at 1150 Marshwood Road in Throop, pipes in landfill gas – gas collected from decomposing garbage – from both Keystone and the Alliance Landfill in Taylor and Ransom Twp., purifying it into pipeline-quality natural gas containing more than 94% methane. Assai then injects the gas into UGI’s distribution system.

Assai is a subsidiary of Houston, Texas-based Archaea Energy. London-based BP acquired Archaea Energy in December 2022 for $3.3 billion, according to BP.

The penalty stems from a notice of violation, or NOV, issued last year by the DEP’s Air Quality Program. According to the Nov. 14 violation letter, the average temperature of Assai’s thermal oxidizer was too low.

A thermal oxidizer, or thermal incinerator, is a combustion device that controls volatile organic compounds, carbon monoxide and volatile hazardous air pollutants by combusting them into carbon dioxide and water, according to the United States Environmental Protection Agency.

By failing to operate its thermal oxidizer at an appropriate temperature, Assai violated the Air Pollution Control Act and its plan approval, according to the NOV.

The DEP required Assai to maintain a minimum average operating temperature of 1,488.6 degrees Fahrenheit in its thermal oxidizer for each three-hour period of operation based on rolling hourly data.

On Oct. 19, 2023, the DEP performed a full compliance evaluation at the facility and requested hourly temperature data for the thermal oxidizer, according to the Oct. 7 consent assessment.

The DEP reviewed Assai’s file and discovered that from Oct. 27, 2022, through Oct. 19, 2023, there were 3,501 hours where the average combustion temperature was below the minimum of 1,488.6 degrees. The low temperatures were not associated with any trips, outages or maintenance, according to the NOV.

Assai provided the DEP with a corrective plan two weeks after the NOV on Nov. 28, including implementing temperature alarms that would notify personnel if the temperature dropped below the minimum requirement, but the average operating temperature was still too low during testing Nov. 29 and Dec. 28, according to the consent assessment.

An updated corrective action plan Jan. 31 included increasing the temperature to 1,550 degrees.

Subsequent temperature data showed average temperatures were above 1,550 degrees from Jan. 16 through April 5, according to the consent assessment.

In an emailed statement Tuesday morning, Assai’s parent company, Archaea Energy, said it “is committed to safe and compliant operations at its plants and is focused on being a good community partner.”

“We have worked closely with the Pennsylvania Department of Environmental Protection to address violations and implement necessary corrective action,” according to the statement.