NEWBURYPORT — The public will learn where a hired consultant firm feels a parking garage might best fit in the downtown at a meeting in mid-September, following a meeting between city officials and a consulting firm yesterday.

Planning Director Sean Sullivan said the meeting is tentatively scheduled for Tuesday, Sept. 15, at 6:30 p.m. in City Hall, pending approval from all the parties involved in the project.

Consultant Tetra Tech Rizzo compiled a team to perform the study and issue a report to city officials. The team consists of parking consultants, architects and a real estate appraiser.

The parking garage would ideally enhance parking for passengers of the MVRTA buses and the commuter rail while supplementing existing parking lots and easing parking problems, Michael Hall of Tetra Tech Rizzo wrote in a memo to city officials recently.

Tetra Tech Rizzo has been working since May to review all of the past parking studies done by the city to determine which sites to move ahead and study further. About 10 sites around the city have been identified over the years, and the firm has narrowed that list down to a possible six.

Those six are now being visited and studied using a list of criteria.

The criteria will be used to determine if the site can meet the requirements for the facility, as well as its accessibility, what impact a garage would have on the environment around the land, and what the estimated costs for acquiring the property and construction would be, Hall told a parking task force set up by the mayor yesterday.

The six locations include Waterfront West, Green Street, Titcomb Street, Prince Plaza, Liberty Street and the MBTA commuter rail station.

The parking study committee includes Planning Director Sean Sullivan, City Clerk Richard Jones, city councilor Tom Jones, City Marshal Tom Howard, Chamber of Commerce President Ann Ormond and Julia Godtfredsen, the mayor's director of policy and administration.

From that list of six, the firm will narrow the choices down to two potential sites based on their findings, Sullivan told the group yesterday.

Those two sites will be given to the mayor to choose the final site, and his selection will have to be approved by the City Council.

"That's something that I think can happen; I'm very optimistic that can happen," Sullivan said, while acknowledging that scenario has encountered difficulty in the past.

For decades, a debate has raged in the city as to where a parking facility could go. Several mayors, including John Moak, have created proposals for different sites, including Green Street, Titcomb Street and Prince Place, but none have progressed or gained support from councilors.

Once the final two are selected, Tetra Tech's team will perform a more detailed analysis, including a land survey, traffic study, environmental impacts, and accessibility. They will provide three conceptual designs for each, Hall said.

Hall said the consulting firm hopes to finish its analysis of the six sites by the end of the summer. At the public meeting in September, citizens can weigh in on the sites before the team completes its work and makes the recommendation for the two preferred locations. The mayor will receive a report with those two locations by the end of October or early November, Hall said.

Last April, the city received notice that the state funding for the parking study project was going to be made available. The study had been in flux for a year.

The state is funding $95,178, and the federal government is contributing $380,000 towards the study. The city is working with the Merrimack Valley Regional Transit Authority, which was the actual recipient of the grant.