With the closing, bankruptcy or change in ownership of nearly every paper mill in Maine in recent years, it is clear the era of communities relying, for generations, on a single large employer for their well-being, and in many instances even their existence, is over. Now, the key to economic survival, or better, vitality, is diversity.

Rather than relying on a single company or industry to move into the Georgia-Pacific mill in Old Town, which closed in March, state and town officials have found a more sustainable use for the mill complex by combining research, energy production and manufacturing. The goal is to have four or five different manufacturers in the former mill, employing more than 1,000 workers.

Under an agreement announced this week, the Old Town mill will be sold for $1 to Red Shield Environmental, a group of private investors who intend to develop and manage the site. Three other companies will lease space from Red Shield to operate their businesses. The closing tentatively is set for Oct. 25.

Tamarack Energy, a renewable energy developer, will operate the biomass boiler to produce electricity for the mill complex. The company will also work with the University of Maine, which recently received a $10.35 million grant to conduct research on using wood to make ethanol, plastics, industrial chemicals and other products now made with oil.

Together, Tamarack and Red Shield intend to hire 20 workers shortly after the closing to run the biomass plant, which was meant to provide lower cost energy for the mill, and 30 to prepare for winter and to convert the mill. The companies say they expect to hire up to 300 workers in the next 12 months.

Portland-based Lamtec Inc. intends to make adhesive labels at the facility. The company hopes to begin producing labels for large, national distribution companies and expects to hire up to 100 workers in the first 12 months and grow to 400 employees in the next four years.

The final component is Hallowell International LLC, a Bangor company that recently began making heat pumps for residential use and wants to use the mill to make the devices for commercial customers. The company now employs 12 people, expects to hire 12 more when the deal is complete and wants to hire 300 within a year.

With this mix, if one venture fails, another can be brought in to replace it. There is also room at the complex for additional companies.

All of these ventures are starting off small, but they have the potential to grow. Paper-industry employment is clearly moving in the other direction. According to a briefing paper prepared in 2004 for the U.S. House Subcommittee on Forests and Forest Health, more than 50,000 pulp and paper mill jobs have been lost nationwide since the mid-’90s. From 1990 to 2003, over 900 mills, pulp and paper plants and other forest product plants were closed.

The governor has negotiated innovative deals and offered incentives to keep three mills operational and to extend the life of the Old Town mill by a couple years. While the governor naturally wants to save every mill job he can, creating new jobs in new and growing industries will pay much bigger dividends long term.