A federal appeals court on Tuesday overturned the dismissal of a challenge by Northeast Pennsylvania landowners to a fracking ban in the Delaware River basin, returning the case to the trial judge for further hearings.

A three-judge panel of the U.S. Third Circuit Court of Appeals sided with the Wayne Land and Mineral Group LLC, which challenged the Delaware River Basin Commission's 2010 moratorium on shale-gas development. A federal judge threw out the lawsuit last year, saying the interstate agency has the authority to review and approve natural gas facilities as "projects" under its jurisdiction.

The court opinion said the definition of a "project" in the 1961 compact creating the DRBC was ambiguous, and ordered the trial judge to conduct more fact-finding on the intent of the compact's authors before ruling on the lawsuit's merits.

The judges said they were not taking sides in the dispute, but Judge Kent A. Jordan's opinion  for panel said some provisions of the interstate compact "suggest that the drafters did not intend to define `project' as broadly as the commission contends."

An environmental group that supports the fracking ban says the commission has the authority to ban drilling under its mandate to protect the water resources of the Delaware River watershed.

"We are confident that when a full record is established that the courts will conclude that the DRBC has not only the authority to regulate fracking and related infrastructure, but the absolute duty to do so." Jordan Yeager, lead counsel for the Delaware Riverkeeper Network, said in a statement.