Puerto Rico's proposed natural gas pipeline is facing increased opposition.

Via Verde, state-owned Puerto Rico Electric Power Authority's 92-mile pipeline, would run underground from Puerto Rico's sole liquefied natural gas terminal on the south coast to power plants in Arecibo and San Juan on the north coast.

The utility says the pipeline would save $1 billion in oil costs each year for the U.S. island territory and slash carbon emissions 64 percent.

State-owned PREPA currently gets 70 percent of its electricity from oil-fired units and 15 percent from gas.

With the pipeline, PREPA aims to use natural gas for 71 percent of its power portfolio, reducing oil-generating power to 12 percent, while cutting coal-based power production to 7 percent and source the remaining 10 percent from renewable sources.

But opponents of the pipeline, many who refer to it as "el tubo de la muerte" -- the tube of death -- question its merits as well as its safety and environmental impact.

University of Puerto Rico Professor Arturo Massol-Deya says Via Verde represents merely a switch from one non-renewable fossil fuel for another.

"As an island we are in the dead end of oil dependence and the government is trading that for the dead end of natural gas, when we have abundant sun, wind and water resources with which to generate the energy we need," Massol-Deya told Inter Press Service News, adding that savings from the switch from oil to gas would "barely amount to 1 cent per kilowatt hour."

Massol-Deya, says the pipeline's safety is compromised by inevitable natural challenges including steep slopes, flood-prone areas and geological faults.

Puerto Rico's Engineers and Surveyors Association, known as CIAPR, urged the government last week to scrap plans for Via Verde and replace it with alternatives to achieve energy diversification that are "more cost efficient, take less time and present less risk for the community and the environment," Caribbean Business magazine reports.

The association's recommendation follows an analysis of the proposed project by its pipeline commission.

"Before embarking on a 92-mile gas pipeline that passes through 13 towns, 1,672 acres of land, 68 roads, 235 rivers and wetlands and 369 acres of water surface, there are innumerable measures to lower the cost of electricity that only require administration and government will to implement," said CIAPR President Angel L. Gonzalez Carrasquillo.

While the project was first estimated at $400 million, PREPA estimates have reached nearly $880 million. Factoring in "change orders" and other extra costs typical of large projects in Puerto Rico, CIAPAR projects the final cost to be at least $1.2 billion.