Citing delays and budget overruns on nearly every project at the World Trade Center site, the owner has announced that current rebuilding schedules and cost estimates are “not realistic.”

In a letter to New York Gov. David Paterson (D), Christopher Ward, executive director of the Port Authority of New York and New Jersey, said “unprecedented challenges” are causing “significant delays.” According to Ward, “the schedule and cost estimates of the rebuilding effort that have been communicated to the public are not realistic. In fact, ...the schedule and cost for each of the public projects on the site face significant delays and cost overruns.”

Earlier plans had claimed the World Trade Center Memorial—the WTC project with the earliest scheduled opening date—would be completed by 2011. Other projects, including the 1,776-ft Freedom Tower and four skyscrapers, a transit hub, a performing arts center and retail space, have had moving deadlines since plans were announced.

Ward said traffic around the site and competing interests among the project’s numerous stakeholders, which include a mixture of public agencies, private developers, more than 100 contractors and more than 30 designers, have made the World Trade Center site “a construction challenge that is as complex as any in the world.”

Ward also sent Paterson a 34-page report outlining the challenges.Ward also suggested formation of a new committee to develop and oversee an appropriate schedule.

A spokesman for the Port Authority said the agency would not comment on the report. Developer Larry Silverstein, who is building three of the five towers, said his projects are on track for completion in 2012. “As demonstrated by the success of 7 World Trade Center, as well as other recent developments in the area, downtown is energized like never before,” he said. “It is vital that we maintain that momentum.”