Scenes of a summer day in Biddeford and Saco: A crew stands suspended in mid-air on a cherry picker, touching up the brilliant white window trim of the brick Masonic Hall (above, at right) on Main Street in Saco. A block away on Saco Island, Mark Claussen blends a maple aioli for the panini he hopes to serve the lunch crowd at his Saco Island Deli. Across the river in Biddeford, a man straightens framing in preparation for a delivery of Sheetrock in a studio at the North Dam Mill.

On this glorious summer morning, there’s one thing that people in these two wildly different cities straddling the Saco River have in common: They’re all getting ready. And if the developments that have occurred here over the past half-dozen years are any indication, residents of these two communities — if taken together, they would be Maine’s second-largest municipality — are wise to prepare themselves. Blessed with arguably Maine’s most impressive inventory of well-preserved, historic industrial buildings and home to an ever-growing concentration of artists, educators, and entrepreneurs, Biddeford-Saco is poised to become the next southern Maine economic hotspot.

“The economic fundamentals of Biddeford are extremely strong,” declares Nathan Szanton. He has partnered with Robert C.S. Monks to convert a circa-1845 cotton manufacturing building into sixty-six mixed-income apartments. The 88,000-square-foot Mill at Saco Falls due to open in November will offer forty units of affordable housing and twenty-six units available at market rates. A third of the building is already booked, Szanton says, supporting the findings of a study he commissioned that put vacancy rates in Biddeford-Saco at less than 3 percent. “It’s located between Portland and Portsmouth, which are both growing areas,” Szanton says. “It’s right on a train line. It’s right on I-95. It’s got beautiful beaches, and it’s got a beautiful river running right through it. Frankly, it reminds me of Portland’s Old Port back in the 1970s — a little rough, but all it takes is some entrepreneurs to see the potential.”

And, recently, entrepreneurs have seen it, to the tune of more than $100 million in the past few years alone. Amtrak invested $2.4 million last year in its new ultra energy-efficient station on Saco Island. That gamble is already paying off through ridership that has risen 8.8 percent at the Saco stop in a single year. Thornton Academy, the private school that also serves as the public school for middle and high school children in Saco and neighboring towns, has spent $7.8 million on two new dormitories in the past two years. Southern Maine Medical Center spent $23.5 million on the new Dorothy Walker Bush expansion to its emergency room. The University of New England spent $26 million this year on a new dormitory and athletic field on Pool Street, which connects downtown Biddeford with the summer enclave of Biddeford Pool. And finally Szanton and Monks’ Maine Workforce Housing company is putting $14.4 million into their mill-conversion project, taking advantage of some $13.2 million in state and federal grants and tax credits to defray much of that investment.

But without a doubt no one has had a greater impact on the optimism building in Biddeford-Saco than Doug Sanford. The fifty-two-year-old Amherst, New Hampshire, native paid three hundred thousand dollars for the three-building North Dam Mill in 2004 after electric blanket-maker Sunbeam vacated it. He is now three-quarters of the way through converting the 380,000-square-foot mill into sixty-six offices, retail spaces, and studios, as well as fifty-four one-, two-, and three-bedroom apartments. This summer he added 713,000 square feet to his portfolio by purchasing eleven buildings vacated by WestPoint Home when it departed Biddeford for good a year ago. All told, Sanford now owns more than a million square feet of real estate in Biddeford, putting him in the driver’s seat for determining the next phase in this former mill town’s existence.

“These are America’s best bones — they’re the pyramids that were built in the Industrial Revolution, ” declares Sanford, who has moved his family into a stunning top-floor apartment in the North Dam Mill. “If I looked at it with a pencil and paper, I would never have done the deal [to buy the WestPoint buildings]. But I was already in, with the North Dam Mill. And now this allows us to keep certain portions, to potentially take some things down. Whatever it takes for the adaptive reuse of these buildings.”

Biddeford Mayor Joanne Twomey sees the diversity of manufacturing, artistic, and service businesses in the North Dam Mill as building on the diversity of the region as a whole. In addition to their historic downtowns, the two cities include everything from the family-pleasing waterparks in eastern Saco to ultra-exclusive Biddeford Pool and environmentally fragile Camp Ellis. “I’d like to see people be able to walk downtown and buy clothing again, and to have people making those clothes and shoes right here,” Twomey remarks. A Biddeford native whose parents and grandparents worked at the Biddeford mills, Twomey says she wants to ensure that the city attracts companies that offer a living wage. “I don’t want gentrification — I want to be reasonable in our development,” she explains.

Sanford is hardly the first to recognize opportunity in Biddeford-Saco. Nearly two hundred years ago a group of Boston financiers seized the potential left behind when the Saco Manufacturing Company, Maine’s first cotton mill, burned to the ground shortly after its construction in 1825. Their York Manufacturing Company on Saco Island began producing cotton shirts and dress goods in 1830, and by 1850 had been joined in neighboring Biddeford by the Laconia and Pepperrell mills. With the Saco River providing power for their looms, an outlet for their waste byproducts, and a conduit to the sea for the schooners that brought raw materials and took away finished goods, the mills proved wildly lucrative for their owners. Workers, many of them French Canadian immigrants, flocked to Biddeford. In 1840, some one thousand people — 80 percent of them women — worked at the York Manufacturing mill alone. By 1900, one of every four Biddeford residents worked at the mills. At their peak in the 1940s the half-dozen mills operating in Biddeford-Saco counted 12,000 people on their payrolls.

And then, almost as quickly as the tide of opportunity had risen, it ebbed. The textile industry shifted to the South and then overseas, leaving behind four million square feet of brick mills within a single quarter-mile area. A Nike shoe factory, tannery, and other textile producers would make a go of it in the Biddeford-Saco mills over the next few decades, but the mills closed, one-by-one, beginning with the shuttering of the first, the York Manufacturing Company, in 1957. The final holdout was WestPoint Home, which survived by producing Vellux blankets. Purchased by billionaire Carl Icahn in 2005, WestPoint persevered until its 121 employees were given their pink slips in June 2009.

As the mills began declining in the second half of the twentieth century, Saco especially recognized the need to diversify its economy, says Saco Mayor Ron Michaud. He cites the growth on the east side of the city limits — home now to everything from Funtown Splashtown to block upon block of auto dealers — and development of the city’s industrial parks as examples of managing growth while maintaining a highly livable city. “The Route 1 corridor could have developed into strip malls, but instead it developed into a recreation corridor,” Michaud says, noting that many people know Saco by this strip, and then discover the revitalized downtown and neighborhoods almost by accident. “Funtown Splashtown is a real attraction, as is Aquaboggan. But that area is also the auto mile of Maine. It provides jobs, it provides revenue for all of us.” He says the beach community of Camp Ellis has also provided a seasonal boost for the city’s revenue stream while offering yet another reason for people to visit.

And yet no one would be foolish enough to say that everything has gone exactly according to plan in either Biddeford or Saco. The economic recession stalled several revitalization projects in mid-stride, chief among them the redevelopment of Saco Island by Harper’s Development Corporation. Originally proposed in 2006 as a $100 million, two-year project to convert the former York Manufacturing Company buildings into high-end condominiums and mixed retail spaces, today the island is home to several state offices, the Run of the Mill brewpub, ninety condominium units, and a handful of galleries and shops. All are housed in the massive Building No. 3. Immediately to the north, however, Building No. 4 looms, largely windowless, the collapsed wooden walkway dangerously teetering against its side a symbol of lofty plans abandoned, or at least postponed.

Mark Claussen, who bought his Saco Island Deli seven years ago, admits such huge empty spaces don’t lend to a feeling of prosperity on Saco Island. “Yeah, the redevelopment has been a little slower than we thought it was going to be,” Claussen says. “But we appreciate being part of a building — it’s kind of a family, where we know people by name and they can just say, ‘I’ll have the regular.’ ” The deli owner points out that despite the recession, his business has grown during each of his years of ownership. He adds that his landlord offers various incentives to help businesses like his expand within the former mill building, something he is in the process of doing.

The key to moving Biddeford-Saco’s fortunes in the right direction may well be finding a way for the two cities to work together on solutions for everything from transportation issues to consolidating certain municipal services. Such collaborations are new territory for these rival communities. “One thing I’ve noticed in my short time here is that there’s a real history of territorial-ness, and we’re trying to break that down,” remarks Ezekiel Callanan, who has served as executive director of the nonprofit Heart of Biddeford economic-advocacy group for the past eight months. “It doesn’t matter who does something, it’s that it gets done.” Callanan’s group is in the process of spearheading a master plan for Biddeford.

Callanan points to new leadership at the Biddeford-Saco Chamber of Commerce, the Biddeford Downtown Development Commission, and the Biddeford Economic Development Department as proof that new blood is coming into leadership positions in the cities. The monthly Biddeford Art Walk, held in the North Dam Mill and throughout the downtown and organized by designer Tammy Ackerman, has succeeded in drawing people out of their cars and onto the streets. The Riverwalk, a pedestrian path that will begin at Mechanics Park on Water Street in Biddeford and then pass through the mill district before crossing over onto Saco Island at Route 1, will be the cities’ first tangible collaboration. “The two cities have never really been linked as far as pedestrian traffic goes, so it’ll be pretty incredible to be able to at last walk between the two,” Callanan declares.

Saco Mayor Ron Michaud says he’s watched the entire region coalescing into a single, marketable identity over the past couple of years. “Unlike twenty years ago, when it was only Saco moving forward, the whole Biddeford-Saco downtown is moving in the right direction,” Michaud says. “The downtown really is one collective downtown, and Biddeford-Saco really is one collective area.”

Mike Reilly has observed the two communities coming together at his Reilly’s Bakery on Main Street in Biddeford. “At one time that Saco River was quite wide, and now it’s not so wide,” says Reilly, whose children and even grandchildren help dish out éclairs and donuts made with the same recipe his grandfather used in the business a century ago. He sees the return of pedestrians downtown as signs of progress, and hopes city governments continue to work together. “We’re trying to deal with a two-city community now,” he remarks.

At the juncture of those two communities are the mills themselves. While abandoned mills have practically become part of the Maine landscape, what sets these mills apart is the remarkable condition that they have mostly been left in. In the former WestPoint storage building — known locally as “the fort” both for its gunport-like windows facing Main Street and the actual fort that stood there in the seventeenth century — concrete floors, some up to three hundred feet long, fill all eight stories. Each gleam as if the night crew has departed only moments ago. This is a testament to the cleanliness that WestPoint managers insisted on wherever their blankets were kept. Likewise the roofs on all the buildings have been replaced, bricks have been repointed, sprinkler systems are up to date, and electrical service is state-of-the-art. The inventory manufactured and stored here represented real money for investors, and great care was taken to protect it even as America’s textile industry faded.

For developers like Doug Sanford, the condition of the mills allows him to consider how best to fill the spaces without the need for immediate repairs and stabilization. “These aren’t like most old buildings in Maine,” Sanford says. “These have it all in place — sprinklers, electric, everything. They’re inhabitable immediately.” In those buildings that were actively manufacturing Vellux prior to Sanford’s purchase, crews are now disassembling massive dryers and other machinery and will sell them on the open market. And while he says he hopes to keep all the buildings intact, Sanford has been informed that each of the massive, thirty-inch-square wooden joists that support each floor will sell for three thousand dollars apiece if he decides to part them out.

Sanford sees a large tech-related enterprise as an ideal tenant for “the fort”; the buildings’ solid construction, limited light, and cool climate would be ideal for a server farm. He says he’s willing to “make a deal” with such a large tenant — even to the point of offering free rent — because he recognizes the benefit they would have on everyone else in his buildings and the region as a whole. He also sees residential uses as a possibility, especially for the buildings’ upper floors with their twenty-foot-high ceilings and views of the Saco River.

“I can leave my apartment, walk over to the Amtrak Downeaster, and have dinner in Boston,” Sanford remarks. “And when I come home, I have a view of the Atlantic Ocean! Tell me where else you can find all that.”

Impediments to economic growth can take many forms, and in Biddeford-Saco it has come in the shape of a smokestack. In the 1980s, as the mills closed and Biddeford’s fortunes declined, Maine Energy Recovery Company offered to build a $45 million waste-to-energy incinerator on the northern edge of the former mill properties in Biddeford, capitalizing on the state’s stated goal of reducing landfill waste while also creating alternative energy. Though there were some in town who questioned the merits of allowing such a facility in the downtown area, the Biddeford City Council approved the plan. In 1987, MERC, as it is called, fired up for the first time.

The debate has raged ever since. Though MERC, now owned by Casella Waste Systems, employs eighty people and contributes eight hundred thousand dollars to city coffers — it’s Biddeford’s largest single taxpayer — the odor it periodically produces by annually sorting roughly 290,000 tons of garbage before it is incinerated is significant. Never mind the green benefits of turning 75 percent of that refuse, roughly half of which comes from Maine, into 21 megawatts of energy (MERC itself consumes 3.5 megawatts of it).

“The odor challenge is most in the summertime, as you might expect,” remarks Ken Robbins, MERC’s general manager. To combat the smell, MERC passes its air through a series of three scrubbers that vent 145 feet above ground level, but even Robbins admits that such a ventilation system doesn’t remove 100 percent of the odor. “We’re hyper vigilant, just being right downtown,” he says. “But no, it’s not the ideal location, for sure.”

“It’s not been a benefit for either community,” Saco Mayor Ron Michaud says. “It’s held us back from our potential. Its presence has been a detriment forever.”

In recent years Biddeford has tried a variety of tactics to deal with MERC, ranging from considering an outright purchase of the facility to roundtable discussions with the company. Today, Biddeford Mayor Joanna Twomey says she believes MERC will disappear on its own. “We’re working around it,” she declares. “Because of the economy, people are recycling more, and they’re going to have to go farther and farther for food for that monster.” (In contrast, MERC’s Robbins says the waste-to-energy movement is actually growing, with more machines in development and new technologies, such as increased recycling prior to incineration, in the works.) Twomey also hints that the new air license the city is about to issue MERC will prove difficult for it to comply with. “I think they’re going to have a hard time with the new air license,” she says. “Ultimately they’re going to have to fix it or get out. We cannot prosper with this facility in the center of our downtown.”

One institution that certainly has not been held back from its potential by MERC or any of the other challenges facing Biddeford-Saco is the University of New England, which contains Maine’s only medical school and boasts a student body of some 4,493 people of all ages. UNE President Danielle Ripich has managed to leverage the best of Biddeford, Saco, and even the relative proximity of Portland in maximizing the school’s growth in recent years. UNE pharmacy students, for instance, spend two years at the Biddeford campus before moving to Portland; dental students will likewise take classes on UNE’s flagship campus before moving on.

“Smart people ‘get’ Maine, and ‘get’ the quality of life that they find in the whole Biddeford-Saco region,” Ripich says. “We can attract people, even if we’re not as competitive for salaries as somewhere else. We have people from Boston who come up two or three times a week. They’ll ride up on the Downeaster, so that’s really allowed us to have a access to a pool of faculty that we wouldn’t have otherwise.”

When it came time to build a new facility to house juniors this year, Ripich says she considered taking advantage of the empty mill spaces downtown (fifty graduate students and faculty members already live in the North Dam Mill). But a combination of financing issues and security concerns ultimately brought the new dorm back to UNE’s main campus on Pool Street in Biddeford. UNE’s $26-million, LEED-certified dormitory and athletic field is due to open this month.

UNE isn’t the only private school using the attributes of the Biddeford-Saco region to its advantage. Thornton Academy Headmaster Carl J. Stasio, Jr., says that his school’s recent expansion into boarding students on campus was undertaken with the realization that the school is part of a larger, two-city community. “Parents from Beijing and Oslo like to know about the historical grounding of our school,” he says. “They like to know of our proximity to Boston through the Downeaster. They’re intrigued when they look at downtown and see the remarkable possibilities that Doug and others are bringing to life.”

Judging by the activity under way in the entire Biddeford-Saco region, they’re not alone.