Connecticut’s state Supreme Court on Thursday upheld a lower court’s dismissal of a lawsuit by the heating oil sector that had attempted to block a state energy initiative expanding natural gas pipeline infrastructure to serve retail customers.

The Connecticut Energy Marketers Association (CEMA) went after the state’s Department of Energy and Environmental Protection (DEEP) and the Connecticut Public Utilities Regulatory Authority for allegedly violating the state environmental policy act by not requiring an environmental review before expanding the state’s gas pipeline network. DEEP and the regulatory commission got a trial court to dismiss CEMA’s lawsuit, and the heating oil organization appealed that decision.

The state’s high court in a 3-1 decision agreed with the lower court’s determination that an environmental impact assessment would only be required for activities funded by or proposed to be done by the state. In this particular case, the gas expansion project was initiated by state lawmakers and developed and funded by private companies.

CEMA, which represents heating oil and gasoline dealers, filed its original lawsuit in 2014 in a 24-page complaint in the Hartford District of the state’s Superior Court, following the Connecticut governor’s signing the statewide energy plan into law the previous year.

In its majority opinion the state high court justices said they had “serious questions” about the heating oil association’s claims. “Whether the failure to prepare [an environmental impact] report constitutes a claim of ‘unreasonable pollution’ is, at best, debatable,” they said.

In 2016, Connecticut’s DEEP updated its first-ever comprehensive energy strategy authored four years ago, covering all energy end-users (residential, commercial and industrial) regarding energy efficiency, electricity, natural gas, and transportation.

CEMA has argued in court that an environmental impact assessment should have been done before the regulatory commission approved an expansion of the state gas pipeline system. The heating oil group argued that more natural gas would mean more methane emissions contributing to climate change issues from global warming.

In its energy strategy update this year, DEEP has projected continuing price and environmental advantages for gas relative to heating oil. Nevertheless, critics besides CEMA have argued that depending on more natural gas could delay the transition to cleaner, renewable fuels, such as wind and solar energy.

DEEP plans to release its final comprehensive energy strategy, including the gas component, in January, following incorporation of the final comments and feedback obtained on the revisions in December.