(CALIFORNIA) A federal court victory by environmentalists has dealt a setback to plans by Los Angeles County to dispose much of the area's waste by sending it by rail to an enormous landfill at an abandoned gold mine on the eastern edge of Imperial County.

An appeals court in San Francisco has nullified a land exchange between Gold Fields Mining Corp. and the U.S. Bureau of Land Management that would have allowed creation of an immense landfill near the desert town of Glamis.

Environmentalists praised the decision, which overturned an earlier ruling by a San Diego federal judge that covered the landfill plan, as a milestone in their fight against the proposed Mesquite Regional Landfill.

Officials with Arid Operations, the firm developing the project and a subsidiary of the company that operated an open-pit gold mine on the property, remain convinced of the public benefit of the project.

At issue is whether the public land involved in a swap between the land bureau and Gold Fields was properly assessed. The appeals court ordered the issue back to the trial court in San Diego to hear claims by environmentalists that the 1,750 acres of public land was far more valuable than the 2,600 acres the land management bureau received in response.

In August, Arid Operations reached a tentative agreement to sell the project to the Sanitation Districts of Los Angeles County for $42 million, pending resolution of the environmentalists' lawsuit.

But both sides agree that if the court decides that the public land was grossly undervalued, as the environmentalists assert, the project could be scuttled as economically impossible for either Gold Fields or Los Angeles County.

Arid Operations has maintained that the privately owned property being transferred to the land bureau is enormously valuable because it includes areas populated by the threatened desert tortoise. Under its tentative sale to the sanitation districts, Arid Operations is liable for any increased costs from the land swap with the BLM.

Despite strong protests from environmentalists, Los Angeles haulers and public officials have dreamed for years of creating huge regional landfills in remote desert areas where trainloads of trash could be dumped. The plan would be similar to Seattle's, which involves rail-hauling waste to eastern Oregon.

At one time, sites in San Bernardino County, Riverside County, and the Imperial Valley were being developed. But only the Mesquite site has cleared the necessary political and regulatory hurdles.

Until the recent court decision, officials at the Sanitation Districts of Los Angeles County, a consortium of 25 independent districts responsible for half the county's waste, had hoped to begin using the Mesquite landfill sometime between 2006 and 2013.

Plans are underway to construct a transfer system from the Puente Hills landfill, the largest of the county's landfills, where 12,000 tons of waste are dumped daily.

By some measures, the Mesquite landfill could be the largest landfill in history--450 feet tall, three miles long, and as much as 1 1/2 miles wide when full. At 20,000 tons a day, the site would take 100 years to fill, officials said. Imperial County officials have sided with the company and provided most of the permits necessary for operation. The proposed landfill has been touted as an economic boon to the impoverished county, which has the right to charge a tonnage fee on each load of waste. By one estimate, the landfill would generate $18 million in taxes and fees annually.

For more information, contact the Los Angeles County Sanitation Districts, (818) 889-7567.