Environmental organizations have so far been unable to stop a proposed liquefied natural gas export terminal on the Delaware River but are hoping to find allies in the incoming Biden administration.

The terminal, in the New Jersey community of Gibbstown, would receive liquefied natural gas from the fracking fields of northeastern Pennsylvania by train or truck and dispatch it to the Caribbean by ship.

Opponents cite what they say would be the risk of environmental damage from the construction and from the operation of the terminal. They also question the safety of transporting 3 million to 4 million gallons of LNG a day through the Philadelphia metropolitan area — to a site that for a century was a DuPont dynamite factory.

The project could be an early test of the Biden administration’s commitment to stronger environmental measures and efforts to combat climate change. It has the backing of local elected officials, business leaders in southern New Jersey and, perhaps most significantly, labor unions that argue it will bring jobs to a distressed area.

New Fortress Energy is seeking to build the terminal, on the Repauno plant site opposite Tinicum Island and Chester, Pa. New Fortress is led by Wes Edens, who is a co-owner of the National Basketball Association’s Milwaukee Bucks and argues that natural gas is a bridge fuel to more-sustainable energy sources in the future.

The company did not respond to requests for comment.

The Delaware Riverkeeper Network, a nonprofit advocacy group, has led opposition to the project, and its members are hoping President-elect Joe Biden’s concerns for his home state of Delaware — downriver from Gibbstown — will tip the balance.

“He was always protective of Delaware’s coastal resources,” Tracy Carluccio, deputy director of Delaware Riverkeeper Network, said of Biden. “They’re at the bottom of the Delaware River watershed, and they get all the bad stuff that everyone’s dumping upstream.”

Even before the coronavirus pandemic struck, natural-gas prices were severely depressed in the United States as stockpiles grew and many oil producers chose simply to flare the gas they were extracting as a byproduct. President Trump actively promoted export sales of LNG as a way to support the market.

Early last year, the Transportation Department moved to allow railroads to transport LNG for the first time, over the objections of environmentalists, the National Transportation Safety Board, Native American tribes and other groups.

The idea, backed by New Fortress, was to get the LNG to saltwater ports where it could be loaded on ships.

Carluccio said that means if the Gibbstown project goes ahead, oceangoing tankers laden with LNG will be sailing past low-income neighborhoods in Chester, followed by the port of Wilmington, various coastal refuges on the Delaware and New Jersey riverbanks, and Delaware’s beaches.

“They get all the danger and none of the benefits,” she said.

LNG has been transported by sea for about 60 years, with few safety issues, but under certain conditions a cloud of escaped gas could ignite, with potentially devastating consequences. A failure of the thermal systems that keep stored LNG at minus-260 degrees Fahrenheit could also lead to what is called a “boiling liquid expanding vapor explosion,” or BLEVE.

The Gibbstown project has received a green light from the Coast Guard, the Army Corps of Engineers, the New Jersey Department of Environmental Protection and — on an administrative appeal last month — the Delaware River Basin Commission.

But the Army Corps and New Jersey environmental rulings have been challenged in court, and Carluccio said her organization plans to take the Delaware River Basin Commission to court before a February deadline. Another possible battleground will be the Federal Energy Regulatory Commission: New Fortress has asked for a ruling saying that the commission lacks jurisdiction over the project, which environmentalists will argue against.

The Natural Resources Defense Council contends that the project violates clean-water laws and regulations. Actor Mark Ruffalo co-wrote an op-ed in the New York Daily News attacking the project. “Every part of the way LNG is extracted, transported and stored is dirty and dangerous,” it said.

The New Jersey Sierra Club argues that the project would damage wetlands that support the Atlantic sturgeon and other endangered species and would spur even more hydraulic fracturing, or fracking, in nearby Pennsylvania.

But some unions have strongly supported the project.

“Since 1902, the International Brotherhood of Electrical Workers has contributed to the industrial growth in communities across southern New Jersey and along the Delaware River,” Daniel Cosner, business manager for IBEW Local 351, wrote in a letter to the river commission. “For the past century, the jobs we have completed have helped build the middle class and ensured the economy works for everyone. This project does just that.”

The terminal “will bring new life to this once-blighted facility while creating hundreds of good paying, union construction-related jobs and providing much needed tax revenue to the community,” he wrote.

Additional support comes from the Iron Workers union, the Pilots’ Association for the Bay and River Delaware, the United Brotherhood of Carpenters and several business associations.

An engineer working for New Fortress, Kevin Webb, told the Greenwich Township, N.J., zoning board that the company expects to operate the dock 24 hours a day, with 50 to 70 permanent employees.

New Fortress has already built one dock at Gibbstown to handle mixed cargoes. The proposed second dock would be devoted to the transfer of LNG or other refinery byproducts from freight cars or trucks to ships.

A wharf, with room for two deepwater ships at a time, would be built out in the river, parallel to the shore, connected to the land by a trestle pier. It would require dredging about 665,000 cubic yards of sediment over a 45-acre area.

The Repauno plant site includes “a diverse and significant amount of hazardous waste” that DuPont dumped into “unlined landfills, sand tar pits, pipes and ditch basins,” according to a suit against the former owner brought by state environmental officials. The land is contaminated by polychlorinated biphenyls, or PCBs, among other wastes.

Opponents of the project argue that the dredging will release PCBs into the river, but the Basin Commission ruled that proper mitigation procedures should be sufficient to contain the pollutant. Representatives from member states New Jersey, Delaware and Pennsylvania voted in favor of the plan; the commissioner from New York, which has dealt with severe PCB pollution in the Hudson River, abstained.

In a letter to the commission, the Natural Resources Defense Council said that “recent scientific evidence has shown that PCBs are far more toxic than scientists or environmental agencies realized even 15 years ago.”

Under the New Fortress plan, the natural gas would be liquefied in Pennsylvania, most likely at a plant in the town of Wyalusing, in Bradford County, about 35 miles northwest of Scranton. The company has suggested that it would run two “unit trains” of up to 100 tank cars every day to the terminal; loading a ship to capacity would take about 10 days.

The LNG would be used to power electric plants in the Caribbean.

Opponents argue that climate change requires a move away from fossil fuels, including natural gas, and that this project would be a step in the wrong direction.

“Fracking is dying. Natural gas is on its way out,” Carluccio said. “We’re totally committed to defeating the export of LNG completely. It’s an outrageous project.”