Across the country, engineers, recyclers, researchers and entrepreneurs are finding new ways to give end-of-life tires a second life.
As part of USTMA’s Full Circle platform and America 250 Second Life Stories initiative, these stories highlight the people helping build sustainable end-use markets for recycled tires while solving real infrastructure challenges in their communities.
MINNESOTA
Monte Niemi, Founder & CEO, First State Tire Recycling / TDA Manufacturing
In Minnesota, nearly five million tires wear out every year. For decades, that meant one thing: a growing disposal problem in every corner of the state. Monte Niemi, Founder and CEO of First State Tire Recycling saw something else entirely; a vast overlooked resource hiding in plain sight.
The Beginning
Monte started in the tire disposal business in 1981, long before “circular economy” was a phrase anyone used. At the time, the job was simple – collect, grade for retreading or wholesale reuse, haul and discard tires that were no longer driveable. But he began asking a different question: what if these tires weren’t waste at all? What if they could be turned into something useful?
The answer he arrived at was Tire Derived Aggregate, or TDA (ASTM 6270-B), engineered pieces of shredded rubber designed for use in civil engineering projects, replacing traditional materials like gravel and soil. TDA has engineering properties that behaves, in many applications, better than the conventional fill materials civil engineers had always relied on. It was a counterintuitive idea that required convincing a lot of skeptics, both in and out of the state.
Building The Market From Scratch
What Monte ultimately built in Minnesota became a model for market development across the country. Today, First State Tire Recycling, based in Isanti, Minnesota, processes between 2 million and 2.75 million tires per year, converting them into engineered TDA products (ASTM 6270-B) under the brand Green Aggregate Fill.
But to get there, Monte had to educate engineers, persuade regulators, and show up at job sites to demonstrate in real-time what TDA could do. Monte’s approach was simple and consistent: treat every project as a show-and-tell and proof for the next one. Build it right, document the results, and bring the next engineer out to see it.
Over time, the results and demonstrated performance spoke. The Minnesota Pollution Control Agency now has beneficial use designation guidelines for TDA actively encourages the beneficial use of recycled tires in engineering applications.
Why TDA Works
TDA has a set of engineering properties that may sound almost too good to be true until you see them in action. Weighing only about 20 pounds per cubic foot loose volume, it is significantly lighter than conventional fill materials. It’s hydrophobic, preventing water from wicking back toward road surfaces. When placed over clay soils, it prevents frost boils that can wreak havoc on northern roads every spring. On hillside slopes, it develops exceptional shear resistance. And its void space ratio – about 50 percent – is roughly double that of crushed rock, making it highly effective in stormwater applications.
While there have been over 400 TDA installations across dozens of different applications, its properties make TDA very well suited for three primary uses: lightweight fill over soft soils, backfill for commercial walls and bridge abutments, and stormwater infiltration galleries. Each application solves a different problem for civil engineers. Together, they represent a versatile second life for over 60 million Minnesota tires that would otherwise end up sitting in landfills.
A Road Map for the Rest of the Country
Minnesota’s experience is now informing efforts in other states. Monte did not wait for policy to evolve – he helped shape it by proving the material worked in the field.
There is room to grow, and Monte is clear-eyed about how much work remains. Minnesota generates more than five million used tires a year and with around 2 million now repurposed, significant capacity remains untapped. As engineers, regulators and contractors continue to see TDA results in action, the demand continues to expand. Every project becomes another proof point. Monte’s methodical approach to market development, hundreds of projects done well, documented carefully and shared openly, shows what driving progress looks like when economic value and environmental responsibility strengthen each other.
Fast Facts
- 2 – 2.75 million tires given a second life annually
- 20+ stormwater TDA installations since 2005
- Up to 40% cost savings vs. conventional fill
First State Tire Recycling processes end-of-life tires from across Minnesota and neighboring states into engineered TDA products for civil engineering applications. For more information, visit firststatetire.com.