Somerville officials appealed the license in February, citing environmental and health concerns stemming from the 18,000 cars expected to drive to the site daily. Media reports say the resort will add ferry service and more green space, but it is not clear if Somerville still will challenge the permit in state superior court.

Robert DeSalvio, president of Wynn Boston Harbor, says the $1-billion-plus construction package is the largest “ever issued for any private, union-built, single-phase development” in Massachusetts.

Jacobs Engineering is the architect for the project, expected to include a 24-story luxury hotel and other retail and office buildings when it opens in 2019. A Wynn spokesman projects peak construction employment at 4,000 workers.

Charter Environmental, a minority-owned Boston firm, has completed the first phase of a $30-million environmental remediation at the casino site, formerly home to a Monsanto Chemical Co. plant.

Wynn is funding the cleanup of arsenic, lead and other pollutants from a portion of the heavily contaminated site, which will be replaced along the river with a six-acre park that will provide access to Boston Harbor. Also, an on-site groundwater treatment plant is returning purified water to the water table, says the Everett Independent newspaper. The casino will open up the Everett shoreline to the public for the first time in more than a century, says Wynn. Shoreline dredging is expected to begin in coming months.