The Natural Resources Defense Council issued an ultimatum Wednesday to the Port of Long Beach demanding it halt all expansion projects and reduce air pollution in 90 days or face a federal lawsuit.

The environmental group, along with the Coalition for a Safe Environment, made a series of demands, including quick implementation of a controversial plan that would replace the port’s aging fleet of short-haul trucks with cleaner-burning models.

“Diesel particulate hazardous waste emanating from operations at the Port of Long Beach is exacting a huge toll on local residents and the environment,” the groups said in a letter to the port.

Representatives of the port could not be reached for immediate comment.

The environmental groups contend that port emissions violate the federal Resource Conservation and Recovery Act. The groups allege that arsenic, cadminium and other toxic particulates contained in diesel exhaust constitute a violation of federal solid waste disposal laws.

Among the other steps the groups are demanding is conversion of ships to low-sulfur fuel, requiring half of all ships by 2009 to use “plug in” shore-side electrical power while docked and installing diesel particulate filters on all trains.

The NRDC is among a coalition of environmental groups that filed an appeal with the L.A. City Council to block a terminal expansion project at the Port of Los Angeles.