SEARSPORT — In a large warehouse at the Mack Point port facility, hundreds of bags of seaweed the size of desks are stacked on pallets. The warehouse’s translucent roof gives off a soft, yellow light, which seems out of place in this setting.

Paul Barrigan, who manages the Sprague portion of the Searsport shipping terminal, said the bags of seaweed—reddish brown where it peeks out from the odd tear in the white-plastic bags—was harvested on shores in African countries. Occasionally, he said, port workers will see a reddish-brown bare footprint left on a pallet.

It’s a striking juxtaposition, the manual harvest of a natural resource on that distant African shore now stacked at this highly developed industrial shipping site.

The seaweed, which arrived at Mack Point by cargo ship, will be hauled by truck to FMC BioPolymer in Rockland, which uses it to create carrageenan, a binding agent in foods like ice cream and products like toothpaste.

This is just one example, port boosters say, of the often-unseen yet vital role Mack Point plays in Maine’s economy.

These days, Mack Point is mostly a wet cargo port. Sprague, the Portsmouth, N.H.-based company that manages about 140 acres of the site, and Irving, which operates on a smaller area, import fuels like heating oil and gasoline.

But the port also handles dry cargo like seaweed, gypsum, newsprint, road salt and wood pellets. The port sees about 150 ships and barges a year, in the 400-800 foot range.

Along with the seaweed bound for the FMC plant in Rockland, other hypothetical scenarios help explain the port’s role.

In a home in Machias this December, a mother will turn up her thermostat to warm the house as her children get ready for school; the furnace will burn fuel imported at Mack Point.

That same December day as snow falls on I-95 north of Bangor, road salt imported at the Searsport terminal will be spread on the roadway, making travel safe.

At a Maine paper mill, clay slurry imported at Mack Point from South America will be used in making the paper glossy. And the Dragon Cement plant in Thomaston will burn petroleum coke, a kind of coal off-loaded at the port, to power its operation.

UNTAPPED CAPACITY

Mack Point was at the center of a regional controversy late last year and earlier this year as a proposal by Denver, Col.-based DCP Midstream sought to build a 23 million gallon liquid petroleum tank on part of the port operated by Sprague. The town planning board ultimately rejected the proposal (as the review process concluded, DCP withdrew its application), ruling in part that the 14-story high tank didn’t fit at Mack Point.

Because the tank farm is largely hidden from Route 1 traffic, there is an “out of sight, out of mind” nature to the port. The numbers associated with the facility speak to its size.

Sprague, which is owned by the Swedish firm Axel Johnson Inc., operates a dozen port facilities around the Northeast, including in Portland and South Portland. Jim Therriault, vice president for materials handling for Sprague, said the company moves 2.5 billion gallons of petroleum products annually and 3 million tons of materials such as clay slurry and road salt.

The company manages nine storage tanks at Mack Point capable of holding 700,000 barrels of fuel. Including the tanks operated by Irving, the port’s capacity is 1.6 million barrels.

The tanks were first built during the Cold War era to store jet fuel that was transported to Loring Air Force Base in Limestone via pipeline. Sprague purchased the tanks from the Department of Defense as part of the process that closed the air base in northern Maine.

Today, the tanks, each sitting on parcels of about 5 acres with berms surrounding them to contain a spill, are used to store #2 home-heating oil.

“Typically, you want to turn tank over 6-10 times a year,” Therriault said, meaning each would be emptied and filled that many times.

“We don’t think it’s at capacity,” he said of the tank farm. “There absolutely is potential in that tank area.”

If petroleum refineries close in the U.S., Therriault said, the storage capacity could become critical for Maine.

The Maine, Montreal & Atlantic Railway’s connection at Mack Point adds to its value as a port, he said. That rail link—which no longer exists in Eastport, for example—helped make the case for federal, state and private investment. In the last 15 years, Therriault noted, some $50 million has been invested in improving the port.

In 10-15 years, Sprague will own the two piers, as the company repays the state for its cost to rebuild what had been 100-plus-year-old piers. The dry cargo pier includes a working surface of 560-feet by 100-feet; the liquid cargo pier has one berth 1,700-feet long and on the other side, a 2,500-foot long berth.

GROWTH POTENTIAL

A representative of Irving, the New Brunswick-based company, declined to speak about its role at Mack Point. But in an email, Samantha Robinson of the company’s public affairs department noted that Irving is “currently in the planning stage to expand” its capacity to handle biofuels for use in gasoline.

With the volatility of the fossil fuel business, and if regional refineries were to close, Sprague believes storage will be critical.

“That’s why we’re not in a hurry to tear down the [former jet fuel] tanks,” Therriault said.

The port also includes 90,000-square-feet of warehouse, including that considered as “food grade” space.

Mack Point also boasts of significant “lay down” pads which are level, concrete areas where cargo can safely be set down and stored temporarily. Components for various wind turbine projects have come through the port, and the large, ungainly sections were stored on the pads while awaiting transport by truck.

“Storage is key,” Therriault said.

The wind components might stay at the port as long as two months, he said. Other component products that have come through the port are large dryers used by paper mills, electrical transformers and generators.

The lay-down areas also are used for road salt, which is imported from South America.

Two years ago, the port added a large crane that can extend 150-feet high and lift 140 metric tons. The mobile piece of equipment has 96 tires, but can be maneuvered with a remote control device. Its bucket can carry 37 cubic yards.

WOOD AND CARBON

Even as the shipping world goes high tech, a likely Maine export for Mack Point’s future is a return to the state’s legacy natural resource—wood.

A product known as torrefied wood pellets—which are similar to those used in pellet stoves, but have been “pre-cooked” to lower moisture content—may be in demand in Europe. Cate Street Capital, the company that now owns paper mills in Millinocket, is building the Thermogen plant in that area to cook the pellets. The fuel is a cleaner-burning substitute for coal and could help the European Union meet a 20 percent renewable fuel standard by 2020.

Sprague hopes to build a storage facility to hold enough of the pellets to fill a ship, Therriault said.

In two years, half the world’s ships will be too large to pass through the Panama Canal, which is why it is being widened. That trend also is impacting ports like Mack Point, as the state Department of Transportation has determined the need to dredge the harbor to create deeper water for those larger ships.

“We’re definitely no where near capacity,” Therriault asserts, despite the town planning board’s ruling. “Not from a dock capacity, not from a land capacity, not from a tank standpoint.”

Searsport Town Manager James Gillway hopes to avoid the rancor that divided residents over the DCP proposal, but notes that it doesn’t control what development proposal is made for Mack Point.

“We don’t have a say in who knocks at the door,” he said. Selectmen are beginning to discuss, though, how they can be more proactive in any growth at the facility.

As Gillway notes, the word “port” is “part of our name. I think of it as integral.”