Ruth Libby never would have guessed, when she first began collecting meat trays and egg cartons for her kids’ school art projects, that one day she would be at the helm of a massive nonprofit business with more than 80 member organizations.

Libby is the director of Ruth’s Reusable Resources, a Maine charity that collects corporate surplus and castoffs and provides them to local schools at a significant discount. For a membership fee of $2 per student, teachers can “shop” for office supplies, craft materials, textbooks and just about anything else that could be useful in a classroom. In the approximately 15 years since it began operating, Ruth’s Reusable Resources – or the “3Rs” as it’s affectionately known by volunteers, board members, and the hundreds of teachers who pass through its doors every year – has saved its member schools approximately $18 million, according to Libby’s carefully maintained inventory records.

“We pay into this program, but we take out so much more. Schools would never be able to afford the kinds of things they offer here,” said Sally Chaplin, a fifth grade teacher from Westbrook who relies on Ruth’s to supply items that her district’s limited budget doesn’t cover.

“You never know what you’re going to find when you turn the corner. It’s like Christmas. It’s so great to be able to use this as a resource to embellish lessons. Ruth is really on the cutting edge.”

Chris Toy, the former Freeport Middle School Principal who now serves as vice-chairman of the 3Rs’ board of directors, agrees.

“When I was a principal, I used to pull something like $10,000 a year out of this place. To be able to save thousands of dollars on your budget for an investment of a few hundred dollars is unheard of. We once outfitted an entire computer lab out of this place.”

U.S. Sen. Susan Collins (R-Maine) recently called Ruth’s a “win, win, win” initiative. Not only do Maine’s schools get additional materials to help educate kids, said Collins, local businesses get tax write-offs for giving away unneeded items they would have just thrown away, anyway. Plus, the environment benefits, as tons of waste are kept out of landfills and fewer nonrenewable resources are used up in the creation and transport of new school supplies.

Even for those who have watched the 3R’s grow over the years, it’s hard to believe Libby went from collecting household detritus for teachers to use in classroom crafts to where she is today.

“Ruth kind of wowed everybody in the New England’s network of re-users and recyclers. She’s kind of unique in what she does, and she does it on a massive scale,” said Debbie Redding Sampson, a member of the board of directors. Sampson only recently moved to Maine, but had long heard about Ruth’s from acquaintances in other parts of New England.

The first big change for Libby came when she sent a letter to executives at Unum, a South Portland-based insurance company, asking for a donation of spare office supplies.

Not only did the company give Libby enough office supplies, taken from the desks of former employees over the course of several years, to fill an 18-wheeler, they also gave her a start-up grant consisting of enough money from to turn her small recycling hobby into her life’s work.

At the time, says Libby, one of the executives told her, “We want to give you the money to do this, but you need to realize how big this is going to get.”

Libby didn’t think anything of the comment then, but now, as she surveys the 27,000 square foot store and warehouse space she moved her enterprise into this past winter, she understands.

“I think somewhere inside, God just told me, ‘This is what you’re going to do with your life,’” says Libby, adding with a laugh, “I don’t think I heard correctly that it was going to be this big.”