The outcome of Liberty Utilities’ petition for a long-term renewable natural gas (RNG) contract will have “a long-lasting impact” on Massachusetts and its climate landscape, Priya Gandbhir, staff attorney at the Conservation Law Foundation, told regulators Thursday.

“There remains significant doubt for many reasons about the viability of biomethane as a sustainable fuel source, as well as doubts around the accuracy of statements about the climate impacts and emissions potential of biomethane,” Gandbhir said during a Massachusetts Department of Public Utilities hearing on Liberty’s petition.

Without clarity on those issues, she added, the state should not approve long-term commitments to procure and combust RNG.

Liberty filed a petition on March 31 (Docket 22-32) seeking approval of a 20-year agreement for RNG supply from Fortistar Methane Group subsidiary Fall River RNG starting in November. The gas utility would blend Fall River’s product into the existing natural gas system.

Fortistar plans to build an RNG facility at the Fall River Landfill in southern Massachusetts to service the contract. As part of the petition, Liberty is seeking approval of a voluntary participation program to allow customers to purchase RNG as a percentage of their natural gas usage.

Utilities in Massachusetts, including Liberty, filed decarbonization plans in mid-March in the DPU’s ongoing “Future of Gas” investigation (Docket 20-80) into the role of gas distribution companies in reducing greenhouse gas emissions. The utilities asked the department to approve their plans, which are still under review. (See National Grid Proposes 100% Fossil-free Gas System in Mass.)

As part of its decarbonization plan in the 20-80 proceeding, Liberty said it would file an opt-in RNG proposal with the department to jumpstart supply by the end of next year and contribute to the state’s 2030 emission reduction target.

The Acadia Center’s senior policy advocate for Massachusetts, Kyle Murray, echoed Gandbhir’s concerns about the petition in his testimony.

“The 20-80 docket … is still ongoing, and a major portion of that is about the viability and safety of RNG and hydrogen,” he said. “We believe that, pending the outcome of that docket, we really should not be making long-term decisions in this instance.”

Approving a plan for blending RNG into the gas system would send a signal to the utilities to “proceed with business as usual,” said Cathy Kristofferson, secretary and treasurer of the Pipeline Awareness Network of the Northeast, in testimony.

“The department must not allow this gas contract petition to be a precedent-setting test case that allows components of the [gas companies’] unapproved net-zero enablement plans to be approved while they do not meet existing regulations or the department’s least-cost supply planning standards,” she said.

In a May 20 filing in its petition docket, Liberty said that litigating climate-related concerns already under review in the 20-80 docket would be “misplaced and inappropriate” in the “narrow” contract proceeding, and the department should not let intervenors, such as CLF and Acadia Center “invoke broader policy issues.”

“The issues that will be adjudicated in this proceeding fall within a narrow standard of review, which, while part of Liberty’s broader proposals in [the 20-80 docket], requires Liberty to make a particular showing to obtain the department’s approval of the proposed contract,” Liberty said.

However, Kristofferson argued during the hearing that Liberty’s May 20 comments demonstrate a duality of thinking by the utility.

“Liberty uses the need to comply with the Global Warming Solutions Act and their participation in the 20-80 proceeding … to justify this RNG contract, yet the company urges … that broader policy issues not be brought into this gas contract proceeding by NGO intervenors,” she said.

Gandbhir asked the department in her testimony to look beyond the narrow scope of the proceeding in reviewing Liberty’s petition.

“CLF requests that the department consider this docket not simply as a standalone petition for approval of this particular agreement, but look at it fully in the context of Massachusetts’ significant efforts to adequately and appropriately plan our climate future,” she said.