About 50 residents of Somerville and Cambridge gather Wednesday at Cambridge’s Kennedy Longfellow School to hear a Green Line Extension update from Katherine Fichter, of the state’s Executive Office of Transportation and Public Works. (Photos: Marc Levy)

Plans for a public market replacing a relocated Lechmere MBTA stop are still on track, with state designs for a new station acknowledging work by an East Cambridge group and City Manager Robert W. Healy clarifying he is not trying to shift the market to the site of a largely abandoned high-rise courthouse.

Residents were alarmed by a letter from Healy about what happens at 48 Thorndike St. when the 22-story building, once housing Middlesex Superior Court and Cambridge District Court but now retaining only a jail, is torn down.

While state agencies have first rights to the property, none has expressed interest in it. Any developer would face some $130 million in rehabilitation costs, while the building is valued at between $40 million and $50 million.

The building may be around for another five years before being torn down, Healy said, and teardown will likely be by hand, since the dense, urban setting and proximity of historic properties makes implosion difficult and dangerous.

A replacement structure would be much smaller, since zoning there now allows for buildings up to 80 feet. Healy wrote:

“We would ask that any site developer consider the inclusion of space, at the ground floor, for a year-round public market. The East Cambridge neighborhood has been actively pursuing this use for the Lechmere Transit Station that will be vacant when the Green Line station is relocated. The courthouse site at 48 Thorndike Street might present another strong option for such a market, with an opportunity to build optimal spaces and other amenities in a new building.”

While residents worried aloud Monday that this meant the city favored the courthouse site instead of the former Lechmere station, councillor Tim Toomey said Healy’s interest in the site as a backup was “a positive.”

Healy thanked him.

“Many others have misconstrued my words,” Healy said. “I’m suggesting the consideration, and clearly the concept of a market in East Cambridge is something we agree upon. We know where we’d love the site … The conspiracy theorists can give up on this one.”

Project officials asked visitors to the Green Line meeting to indicate with pins where they lived and worked.

Among those initially worried by Healy’s letter was Alan Greene, who followed attendance at Monday’s council meeting by joining some 50 other Somerville and Cambridge residents at a meeting Wednesday at the Kennedy-Longfellow School hosted by the Green Line Extension Project team. The main purpose was to gather comment (by Post-it Notes on whiteboard) on what residents liked about the Lechmere station area and their hopes and fears for when the station moved to the other side of the seven-lane Monsignor O’Brien Highway, away from the Cambridgeside Galleria to the stalled NorthPoint development.

When the station moves, the emptied site would be sold or leased to developers by the Massachusetts Bay Transit Authority, said Katherine Fichter, project manager for the extension project.

The meeting also provided a progress report. The final environmental impact report on the project is due June 15, Fichter said. The filing will be followed by a June 30 meeting at Somerville High School, midway through a 30-day public comment period.

Greene liked some of what he saw on plans for the station.

“There are a couple of things that are accommodating to what we’re asking for,” he said. “There seems to be kind of an entryway that’s been placed oriented towards Route 28 and Monsignor O’Brien Highway that wasn’t there before, and that’s what we were asking for. It isn’t as good as what we were asking for, but that is accommodative. Apparently there will be some indoor waiting areas, that’s what we’ve been asking for.”

The plans also show the highway being widened, though.

“How are they encouraging public transportation and expanding the highway at the same time?” Greene asked. “We’re asking that the right-turn lane be eliminated and that they eliminate one lane going toward Boston … as it stands now, there are six lanes now and a pinch point further down, so it’s four or five lanes further down towards Boston. If that pinch point can exist now, it certainly could exist at the bus station.”

“That’s our main point of contention right now,” he said. “We want to save the bus station, and in the current plan it’s necessary to tear down the station.”

The station has beautiful, 1920s-era architecture that should be preserved, he said, and is placed perfectly to serve mall traffic and “the whole area” as well as residents, while he courthouse is hidden three blocks away.

The June 15 report will have to be analyzed to understand the state’s rationale, Greene said, and neighbors have expert waiting to do so.

East Cambridge residents also want to widen the planned 15-footwide pedestrian zone across traffic to where they propose a 12-story hotel, separate commercial building of up to four stories and, between them, a plaza and year-round, 30-stall public market under a refurbished T garage roof.

Greene said he recognized Healy’s comments on the public market and courthouse had been “misconstrued” but urged the city “don’t confuse the two issues.”

Although Lechmere is the current focus, the green line extension project includes a one-stop spur to Union Square in Somerville and five to six stops into Medford, including to Brickbottom, Gilman Square, Lowell Street, Ball Square, College Avenue and finally to a Route 16 stop — and potentially the Union Square spur — being shifted to the project’s second phase.

Officially, all are to be built by Dec. 31, 2014, said Bill Deignan, transportation manager for Cambridge. That’s seven stations going up within four and a half years.

“They’re trying to think of strategies to make that happen,” he said Wednesday.