SEARSPORT – The question of how much expansion is possible at the industrial port facilities at Mack Point, just a half-mile from Sears Island, loomed large on Saturday at a planning session on the island’s future.

Some suggested by reconfiguring or removing tanks and buildings on the 70-acre parcel, the warehouses needed for break-bulk cargo could be built. Adjacent acreage also could be purchased, some said.

Others said the port is nearly maxed out, and argued for retaining the northwest quadrant of Sears Island, where a cargo port was planned for decades, because of the more than 40-foot deep water accessible there.

Casting further doubt over the question is the uncertainty of predicting future shipping needs relating to fuel; with the end of the oil age near, unknown fuels may require an unanticipated means of shipping.

While a market study of Mack Point’s potential may settle the argument, here are some facts about the port as it was and is now:

. In the late 1990s, after then-Gov. Angus King dropped the state’s bid to build a $70 million single-berth container cargo port on Sears Island, the quasi-municipal Maine Port Authority – originally formed to help build the Sears Island port – was reconstituted. The port authority then worked for a $26 million upgrade of Mack Point.

. In 1998, Maine voters supported a bond issue that essentially loaned much of the money for the project to Sprague Energy and the Montreal, Maine and Atlantic Railway, the port operators and users, to rebuild the two piers. The companies repaid the borrowed money.

. The rebuilt steel-reinforced concrete dry cargo pier was completed in 2003; at its widest, it measures 100 feet, and is 800 feet long, making it resemble a four-lane causeway without guardrails.

. At a ribbon cutting event in July 2003, Brian Nutter, executive director of the Maine Port Authority, said analysis showed that because of highway and rail connections, the new pier “will be capable of serving the international transportation needs of Waldo, Somerset, Penobscot, Piscataquis and Aroostook counties.”

. Rails can be installed in the deck if needed, Nutter said, just below the surface so as not to interfere with truck traffic. Ships can approach the pier from either side; the water depth is 40 feet on the east side and 32 feet on the west side.

. The liquid cargo pier, to the west, has a berth of about 700 feet long, with 37 feet of water at mean low water, and a berth of about 500 feet long, with 25 feet of water at mean low water.

. The Maine Ports Web site lists: 1.6 million barrel active tank capacity; truck and rail loading racks; five paved storage pads; truck and rail access; 90,000 square feet of warehouse; and 70-plus acres for development.