Early phase work finally has begun on the planned 20-year development of Treasure Island. The plans had been debated for many years, but little progress had been made until 2011 when the city approved the current incarnation of the proposal.

Plans were held up for decades while officials negotiated land transfer from the Navy, according to Curbed. Debate centered around environmental concerns around possible toxicity and “seismic soundness of the island’s landfill construction.”

The redevelopment could include 8,000 residential units (one-fourth of them will be affordable housing), three hotels and large spaces for commercial use. Of the acreage set aside for the project, 65% will be green space. A planned ferry terminal and service will make transportation to and from the island much easier.

Those involved with the project include Wilson Meany, Stockbridge Capital, Lennar Corp, Perkins+Will and Kenwood Investments. Skidmore, Owings & Merrill will be the master architect.

The island was built for the 1939 Golden Gate Exposition. [Curbed]