Developers of Dallas' new sports arena have finished cleaning up the polluted site where American Airlines Center is being built, state officials said Thursday.

Crews removed more than 70,000 cubic yards of contaminated soil from the former industrial tract along Stemmons Freeway north of the West End.

That much dirt piled on a football field would be more than 40 feet high. "The good news is that there were no big surprises," said Jud Perkins, a senior vice president for Hillwood Development Corp., the firm overseeing the arena construction. "What we found was pretty much what we anticipated would be there."

The arena site has been used for a power plant, rail yard, meat-packing facility and landfill. Environmental tests concluded that it was polluted with oil and chemicals that state law deemed unsuitable for commercial property.

The Texas Natural Resource Conservation Commission has issued certificates showing that Hillwood met the conditions of the state's Voluntary Cleanup Program, which allows property owners to remove contaminated soil under state supervision.

As part of an agreement with the city last year, Hillwood promised to clean up the land to the state's satisfaction before deeding ownership to the city.

State officials visited the site during the cleanup and reviewed tests conducted by Hillwood that showed the contaminated soil had been removed, said Chuck Epperson, the state's cleanup program manager.

Irving-based Entact Inc. has finished cleaning 29 acres and is completing work on the rest of a 65-acre tract that Hillwood owns, Mr. Perkins said.

The arena will occupy about 12 acres. Hillwood and other investors plan to build apartments, stores, hotels and restaurants on the rest of the land.

Hillwood spent $2.1 million to clean the arena site. The city will reimburse the company more than $1 million for the work as part of its $125 million contribution to the arena project.

The contaminated soil was hauled to landfills in Lewisville and Hill County, Mr. Perkins said. Much of the material was black, sooty stuff that appeared to have come from a garbage-burning plant that once operated in the area, said Reagan Rorschach, Entact's project engineer. "It had a distinctive, putrid-type odor," he said. Mr. Rorschach said workers unearthed intact bottles, shoes and metal scraps. Much of the material had been burned, he said. Crews did not find a locomotive rumored to have been buried decades ago on the site.

American Airlines Center, which will be home to the Dallas Mavericks basketball team and the Dallas Stars hockey team, is tentatively set for completion in fall 2001.