Two years ago, the Port of Duluth-Superior had a problem.

Freshwater bacteria were eating its steel ­pilings. Old growth tree lumber was a possible replacement but was hard to get, expensive and would bring maintenance problems of its own.

Instead, the harbor found an answer with Bedford Technology, a Worthington manufacturer that makes plastic pilings from recycled milk, juice and detergent jugs and fiberglass rebar.

“We have been really impressed with it,” said Chad Scott, president of AMI Consulting Engineers, the company hired to solve the harbor’s problem. The plastic pilings don’t crack. They don’t rot like wood. And because ice doesn’t stick to plastic, it can’t rip the pilings from the lake floor.

After passing AMI’s yearlong engineering tests in Duluth, Bedford Technology added the pilings to its other plastic lumber offerings and started marketing to other clients.

The manufacturer is one example of sustainable businesses in the state displaying their products at this year’s Minnesota State Fair. Other companies include garden-product maker Master Mark in Paynesville, By The Yard furniture maker in Jordan and Revolution Plastics, an Arkansas-based company taking farm plastics from Minnesota and other states to make new agricultural products.

“This stuff is amazing,” said Wayne Gjerde, the recycling market development coordinator for the Minnesota Pollution Control Agency. His job is to help transform factory, farm and post-consumer trash into new products and new ­revenue streams.

Every year, Gjerde is tasked with making a statement on how recycling can spare Minnesota landfills and improve the life of fairgoers. So besides the company presentations, there’s also a giant statue of Paul Bunyan made from recycled textiles that will “speak” to people about how their recyclables are used.

When Gjerde heard about how Bedford’s new lake pilings would keep tons of trash out of landfills, he asked Bedford for a sample to display in the Eco Experience building at the fair.

“One thing about goods made out of recycled materials is that they have to be better than what is already out there. And these are,” Gjerde said.

Bedford employs 115 at its Worthington factory. Statewide, 18,000 manufacturing jobs are directly tied to recycled materials, Gjerde said.

Michael Nesdahl, vice president of marketing for Bedford, said his company uses millions of tossed milk and juice jugs, detergent and shampoo bottles and other No. 2 plastics that get collected curbside in Minnesota, Wisconsin and Illinois.

“We get our bottles from all over,” Nesdahl said. “We use recycling facilities, waste management companies and counties. We process all of this No. 2 high-density polyethylene in huge bales that are so big it would blow your mind. They are 4 feet high and 8 feet wide and can be 40 feet long. We sort and clean it,” process it and sell it.

Bedford launched its freshwater pier pilings at trade shows in March and recently won an order from AMI to make the anchor piles for another client’s large dock.

While the freshwater pilings are new to its arsenal, Bedford Technology has made larger pilings for saltwater marinas for about a decade. The saltwater pilings are extra thick and incredibly strong, so they can withstand the pressures of the sea. But lake harbors need smaller pilings and are exposed to different elements. Until now, Bedford Technology didn’t know how to make a smaller product for freshwater lakes that was sturdy enough to survive extremely cold climates.

“The technology has finally come a long way, so we have the ability to produce the types of strength we need” for smaller lake pilings, Nesdahl said.

The same small pier technology is now being used to make a new product — hefty trestles for wine vineyards, he said. A trestle sample also is on display at the fair.

In the same display area, Master Mark of Paynesville is exhibiting its garage and patio floor tiles and its elevated garden bed kits. Both are made from recycled milk jugs and plastic bags. The products sell in Menards stores and online at Home, and

“Our online business is a little bit scary with how it’s grown,” said Mark Reum, CEO of Master Mark’s parent company, Avon Plastics.

Four years ago, Master Mark’s online sales were $250,000. “Today, they are over $1 million. It’s incredible. It’s just so exciting,” Reum said.

Brita Sailer, executive director of the Recycling Association of Minnesota, said she’s excited about all of the displays but particularly excited to see one new product that took years to bring to fruition.

Last month, Revolution Plastics distributed 1,450 huge dumpsters to Minnesota farmers, so the farmers can collect and recycle miles of plastic silage feed bags, crop covers and bale wraps for the first time.

Once a dumpster fills with at least 2,000 pounds of agricultural plastic, Revolution Plastics collects it and trucks it to Sauk Centre or Winona, where it is washed, shredded and baled.

Those bales are hauled to Revolution’s plants in Arkansas and Texas, where they are made into garbage bags used in parks and municipalities across the Midwest. Revolution announced this month it also will begin to turn the recycled plastic into new silage bags and crop covers for farmers. “This is a one-of-a-kind closed loop recycling,” Sailer said.