New Orleans ? Mayor Ray Nagin on Monday ordered waste haulers to stop depositing debris in a controversial landfill opened after Hurricane Katrina, a move state regulators said could delay the battered city’s cleanup by more than a year.

City officials said the emergency authorization allowing the landfill to accept waste was about to expire and the company running it, Waste Management Inc., had not applied for a new permit. If it is closed, trash trucks will probably be sent to a dump 20 miles away.

The landfill was opened to accept debris from Katrina, which created an estimated 22 million tons of trash. By comparison, the state’s largest landfill handled only 1 million tons of debris in an average year. At least 30,000 homes in the area have been tagged for demolition.