Rhode Island Department of Environmental Management officials estimate it will cost between $4 and $5 million to redevelop the old Chase Marina property at 169 Riverside Drive, which has been vacant since the construction of the new Sakonnet River Bridge.

Last month, DEM officials began soliciting non-binding proposals on how best to develop the quarter-acre site, which includes a two-story building and a series of slips. Responses are due Friday, Sept. 9, and after that the state will seek formal proposals from prospective tenants.

Bob Ballou, assistant to the director of the DEM, said last week that the state has $1.3 million in state funds budgeted and approved for the project, and anticipates the rest will come from a combination of federal and private sources.

While the state currently runs two commercial ports — one in Galilee and the other, Pier 9 in Newport — officials have long sought a third in the East Bay area, he said.

"We envision this as the third leg of a three-legged stool," he said — "a new state commercial port facility (and) the first ever in the East Bay."

DEM officials are working with the state's congressional delegation in Washington, DC, and hope that federal funding will be approved for the project, he said. As for the private portion, "it would be our hope and expectation that there would be private sector contributions toward the facility. That would be in the form of a negotiated lease. We think that's a great way to leverage the state and federal funds."

"What we're looking to do is essentially (develop) the marina portion using public funds, and then utilize public funds as well to ensure that the building is essentially ready for one or more tenants. Depending on who they would be, there is an expectation that they would invest in the further development of the facility."

In announcing an informal RFI (request for information) on the project three weeks ago, state officials said their goal is to gear development at the site toward the fishing and shellfishing industries, and associated trades and other businesses.

If all goes as planned, DEM officials hope to have to redevelop the property over the next two years, with the site being fully operational by 2025.

Tiverton Harbor Commission members discussed the state's plans at their most recent meeting, and held an informal walk-through Tuesday morning with state and other local officials. Several neighborhood residents concerned with the future of the facility showed up, as did former owner Frank Chase of Little Compton.