Redevelopment of the Fair Haven waterfront has entered the implementation phase.

Earlier this month, the New Haven Board of Aldermen approved the state’s designation of 42 acres between River Street and the Quinnipiac River as part of a municipal development plan. The classification allows the city to acquire properties via eminent domain, create an implementation plan, and apply for state financial assistance in redeveloping the site, all of which will begin over the next six months.

“The next step is to talk to the property owners so that the city can begin the design and implementation phases,” said Helen Rosenberg, a New Haven business services officer.

The redevelopment of the River Street property will transform the blighted region into a blend of light industrial, commercial and residential complexes separated from the Quinnipiac River by a strip of open space. An 8 acre, inactive Hess oil distillation plant and a junk yard belonging to Lloyd Terminals, Inc., currently occupy large sections of the River Street tract. Other occupants include a Meyers distributors’ warehouse that is 80 percent vacant, an inactive Dupont chemical distribution center, and the Regan Metals scrap yard, Rosenberg said.

“The plan will replace vacant buildings and petroleum tanks with mixed-use facilities,” New Haven’s Economic Development Administrator Henry Fernandez said. “It’s a badly needed change.”

New Haven applied to the state Office of Policy and Management for the parcel’s municipal development plan designation in October. Rosenberg expects to meet with the Fair Haven property owners over the next six months about acquiring their land, perhaps the most challenging aspect of the redevelopment.

But city officials said they will not allow property owners to stand in their way now that the zone has municipal development plan status.

“We have the authority, and we have the money,” Fernandez said.

The board also approved $10 million of municipal bonds for the project in early January, Fernandez said.

The project is estimated to cost $20 million in all, Rosenberg said. In addition to the bonding, New Haven will apply to the state for $8 million in redevelopment funding. Contributions from private developers should cover the rest of the project’s cost.

Rosenberg said she already has spoken with all but one or two of the parcel’s current property owners within the past year and expects most to agree to sell their land to the city or upgrade their sites according to a redevelopment plan.

“We hope to work with these property owners and not have to push things,” Rosenberg said.

The Lloyd Terminals and Regan Metals’ junk yards provide the main hurdles because few sites are zoned for scrap yards.

“The bigger issue is going to be trying to accommodate the relocation of the scrap yards,” Rosenberg said.