OLD TOWN, Maine — Casella Waste Systems Inc. subsidiary EcoGas LLC has filed a petition for preliminary approval with the Maine Public Utilities Commission to build and operate a seven-mile pipeline to send Juniper Ridge Landfill gas to the University of Maine in Orono.

The pipeline system would move methane gas from the landfill to UMaine’s Steam Plant, where it would be used to run boilers and create heat for campus buildings.

Made of 12-inch diameter high-density polyethylene pipe, the gas pipeline would run south to Route 43 before turning east on Route 43 to the intersection with the College Avenue Extension, where it would continue on to the Steam Plant. Casella expects the project will cost between $11 million and $13.5 million to design, build and permit.

The university and Casella reached a deal in November 2011 after about three years of discussion.

UMaine Vice President for Administration and Finance Janet Waldron said in November that the 20-year agreement is expected to save the university a total of about $15 million.

The University of Maine System’s flagship campus expects the move to landfill methane gas will cut the campus’s carbon emissions by 40 percent — a big step toward the university’s goal of reaching a zero carbon footprint — according to Waldron.

“Combusting methane also creates a potential revenue in the carbon offset credit market,” Casella Manager of Planning and Development Don Meagher wrote in his testimony in the petition. “When combusted, methane is converted to carbon dioxide, which reduces the greenhouse gas impact by 96 percent.”

That cut in emissions can be “traded” on carbon offset credit markets, providing revenue, Meagher said. The University of Maine would receive 92 percent of the revenue from those credits.

“Casella and UMaine have worked collaboratively for more than three years to develop a pipeline that will provide economic and environmental benefits to both parties,” Meagher said.

According to the agreement, Old Town will receive 5 percent of Casella’s gas sales revenue, 8 percent of the carbon offset credit attributes and free landfill disposal of the town’s waste treatment plant sludge.

Casella needs the commission’s initial approval before seeking final approval, which would allow the EcoGas to begin construction.

The PUC will hold an initial case conference on the EcoGas petition at 10 a.m. April 25 in the PUC’s Ballard Room, 101 Second St., Hallowell.

Casella hopes to complete the permitting process for the project by Dec. 31 so it can begin construction by March 2013, according to the petition. The pipeline could be ready to send gas to UMaine by the winter of 2013-14.