The controversial, 420-megawatt wind project off the Massachusetts coast is facing a new hurdle barely a month after winning a critical regulatory support for the project.

The Federal Aviation Administration on Friday issued a “notice of presumed hazard??? for the project, saying the wind farm could hamper the performance of three nearby radar systems operated by the FAA.

The notice the wind farm could cause the most impact on one of the radar systems. To upgrade or replace this radar system would be some of the possible solutions. The most expensive option would cost the project developer, Cape Wind Associates, up to $15 million.

The project has encountered stiff opposition from some residents of Nantucket, Martha’s Vineyard and Cape Cod since it was proposed in 2001. U.S. Sen. Ted Kennedy, D-Mass., has sided with the residents in opposition to the project, citing the wind farm’s potentially negative impact on the environment in Nantucket Sound. Cape Wind set out to build the first offshore wind farm in the United States. The project would consist of 130 wind turbines.

Cape Wind won an important support last month when the federal Minerals Management Service, part of the U.S. Department of Interior, released an environmental impact report that favored the project (see Cape Wind Project Gets Thumbs UP). The service had to wait for at least 30 days before it could issue a decision to give the developer a lease to build and operate the wind farm.

Mark Rodgers, a spokesman for Cape Wind, said the company has had to work with the FAA to address other concerns in the past, so it expects to resolve the latest issue in the next few months.