WYNN RESORTS on Friday moved a big step closer to beginning construction on its $2.7 billion hotel and casino in Everett when a state hearing officer said the Las Vegas company is deserving of a key environmental permit with a handful of modifications.

The hearing officer, Jane Rothchild, recommended to the commissioner of the Department of Environmental Protection that he approve the permit but change its duration from 85 to 50 years. She also said Wynn should be required to operate its ferry service to the casino for the entire license period, be required to provide 6.38 acres instead of 4.36 acres of open space near the dock, and provide funds for a fishing pier and a canoe-kayak launch near the facility.

In ruling on an appeal brought by Somerville Mayor Joseph Curtatone, Rothchild said the casino would not “significantly interfere” with navigation on the Mystic River. She also ruled that the “preponderance of evidence” supports a finding that awarding the permit was justified because Wynn intends to clean up a polluted site and restore public access to the river.

If the DEP commissioner accepts Rothchild’s recommendation, which is expected, Wynn Resorts plans to start construction immediately.

Rothchild’s decision was released at 4:59 p.m. Friday.

Bruce Mohl oversees the production of content and edits reports, along with carrying out his own reporting with a particular focus on transportation, energy, and climate issues. He previously worked...