Long dormant strip of Boston’s working waterfront finally gets a new use

For years, the Massachusetts Port Authority has tried to draw marine industrial businesses to a 30-acre stretch of the South Boston waterfront, and to revive a dilapidated deep-water berth on the property.

Now, Massport has a deal in hand to help accomplish both goals. On Thursday, the port authority board approved Eastern Salt Co.’s proposal to use a section to unload and distribute road salt to customers south and west of the city. In return, Eastern Salt will spend tens of millions of dollars restoring the deep-water dock known as the North Jetty for the Lowell-based company’s use. It will also make the jetty available for other industrial users, to bring in heavy machinery or power plant equipment, for example.

Massport chief executive Lisa Wieland said the agency has had to turn away marine freight business because of a lack of adequate facilities. With this deal, the port authority will be able to direct requests to bring in heavy equipment by barge to Eastern Salt.

She is also hopeful the berth could play a role in serving the region’s nascent offshore wind industry. The port authority’s nearby Conley Terminal in South Boston is equipped for accepting goods that arrive via shipping container, not freestanding machinery.

“Frankly, it’s pretty busy, and we don’t have the storage space for that kind of stuff even if we were able to figure out how to unload it,” Wieland said of Conley. “There’s a lot of unmet demand in the port.”

The deal approved on Thursday designates Eastern Salt as the long-term lease-rights holder for about 10 acres at the outermost section of the Raymond L. Flynn Marine Park, alongside Fid Kennedy Avenue.

With that vote, the final major pieces fall into place for the Massport Marine Terminal jigsaw puzzle. While Legal Sea Foods occupies one corner of the 40-acre property, most of it had been tied up for years in an unsuccessful deal with warehouse developer Cargo Ventures.

About five years ago, Massport tried a different approach — carving up the remaining 30 acres into subplots for different users. A deal with Cargo Ventures for a seven-acre slice fell apart, too. But Massport reached subsequent deals with Pilot Development for that portion and an adjacent parcel. A seafood plant, currently used by Boston Sword & Tuna for its headquarters and processing, opened last year on one of the Pilot sites. Cape Cod Shellfish & Seafood Co. secured another piece. Only one acre near the Legal Sea Foods fish processing facility still needs a developer designation.

The marine terminal area is largely landfill, built with dirt from MBTA tunnel construction in the 1980s that filled out what had once been a set of “finger piers.” For a long time, though, the Legal Sea Foods facility (now owned by Irish private equity firm Danu Partners, which recently acquired the Legal restaurant group) and an adjacent seafood processing plant were the only significant buildings on the property.

Wieland said the precise financial terms with Eastern Salt are still being worked out. The cost of rebuilding the North Jetty will represent the bulk of the company’s investment, she said.

“The reality is, we didn’t have the money to invest in it to restore it to the state it needs to be in to really operate as a full-service berth and terminal,” Wieland said. “There’s still some negotiation that needs to take place, to button up all the terms related to this deal. This is about a significant private-sector investment to restore a much-needed berth in the harbor.”

Jon Chesto can be reached at jon.chesto@globe.com. Follow him on Twitter @jonchesto.