DOWNLOAD YOUR COPY (PDF): TDA Manufacturing worked with the U.S. Tire Manufacturer’s Association to provide a table-top display and samples of tire-derived aggregate (TDA) for the attendees of the American Association of Highway and Transportation Officials (AASHTO) annual meeting and conference, taking place October 19-23 in Orlando, FL. The AASHTO Annual Meeting, one of the transportation industry’s most important conferences of the year, brings together experts from the public and private sector to share the latest in industry policy and innovation. Attendees network with fellow transportation professionals and contribute to discussions on a wide range of issues facing the industry today and tomorrow. Our hope is that these materials provide a touchpoint for ongoing discussions about the use of TDA in engineering projects related to highway and transportation challenges. TDA helps increase the safety factor of engineering plans/designs, saves on cost of materials, and can be utilized in projects seeking LEED, GREEN ROADS or Green Build certification!

Steve Hass, Proprietor of Hass Construction, has been responsible for township road maintenance for over 30 years. Stanchfield Township (Minnesota) is one of the many townships his company maintains roads for. Steve and the township officials wanted to improve a section of 381st Avenue that crosses a peaty, swampy area. This swamp crossing is 15-20 feet lower than the sandy knolls on both sides of the swamp. The solution is to elevate the valley, to make the roadway easier and safer, improve driving safety for the area’s residents by leveling out this particularly bad area, and reduce the historic issues with frost heaving and flooding. “Elevating the valley by approximately 8 feet makes for a smoother and safer ride, and protects the surrounding land,” said Monte Niemi, CEO of TDA Manufacturing in Isanti, Minnesota. Tire-derived aggregate (TDA) was chosen as the lightweight aggregate fill for this project due to its interlocking “snowshoe effect” – where the pieces weave together, helping to spread the weight of the driving surface over the soft the organic soils under the current road. TDA possesses a standing beneficial use designation in Minnesota, which means that it can be used as lightweight fill without a permit (when used in accordance with MPCA directives) for any road construction project that is managed by a professional engineer. For the full story and photo history, visit the Project Gallery.

Over three days in August, TDA Manufacturing (Isanti, MN) hosted the producers of Into the Outdoors, an education network that empowers today’s youth and adults to think critically about our planet. Part science lesson and part adventure, Into the Outdoors uncovers the stories behind sensible solutions to creating a better planet while the kid hosts have fun along the way. ITO also arms educators with video resources and lesson plans in various science categories. They were at TDA Manufacturing to film portions of the documentary “Sustainable Waste Tire Solutions,” which will feature the many environmentally friendly uses of tire-derived aggregate (TDA). Over the course of three days, twelve-year-old host Wesley and the production crew trekked to: An apartment construction site in Burnsville, MN, to learn how TDA can solve challenging building issues, such as lateral pressure created by uneven soil levels Purgatory Creek Recreation Area (Eden Prairie, MN), to see a TDA installation in a muddy wetland area that’s stood the test of time (20 years!) The Minneapolis Convention Center, where TDA was used in a below-ground parking ramp The University of Minnesota, where Wesley interviewed professors researching the capabilities of TDA in stormwater and clean-water applications The team wrapped up the whirlwind tour by interviewing Monte Niemi, CEO of TDA Manufacturing, who gave a brief history of how far we’ve come in our understanding of TDA. Watch for “Sustainable Waste Tire Solutions” to air in early 2023 on various broadcast and PBS stations. Check the schedule.

The Environmental, Economic and High-Performance Product for Your Engineering Designs Learn More WHAT WE DO MANUFACTURE SUSTAINABLE AGGREGATE ​ TDA Manufacturing - a Division of First State Tire Recycling is an industry leading producer and distributor of TDA (Tire Derived Aggregate) . Building on years of industry expertise, we give new purpose to end of life tires. Our value-added solutions provide environmental, economic and performance benefits for the most challenging civil engineering projects. Why work with us? TESTIMONIALS Read Here RECOGNITION EXCELLENCE IN RECYCLING ​ Certificates of recognition given to projects where our Tire Derived Aggregate was installed. Award Award Award Award 1/6

Frequently Asked Questions about TDA (TIRE-DERIVED AGGREGATE) Where does TDA come from? Our recycling facility (First State Tire Recycling ) collects discarded used tires from across Minnesota. These end-of-life tires are used as feedstock in the manufacturing of TDA. This feedstock flows through our slow-speed, high-tolerance shredding machines (sharp cutters are necessary to produce clean cuts without leaving significant amounts of exposed wire). A single pass through the machine produces a product called rough shreds . Running the material through two shredders can produce the ASTM 6270 type B, TDA-sized tire shreds. ​ How is TDA used? You might be surprised by the number of places TDA is being used today. Some examples include road repair/construction; stabilizing embankments; backfilling bridge abutments; preventing frost in driveways and parking lots; stabilizing parks/recreational trails; septic system drain fields and underground stormwater systems; rain gardens; landfills and gas collection; and backfilling retaining walls. See applications . ​ Why use TDA? ​ The idea for utilizing shredded tires in construction applications spurred from the legislated prohibition of land-filling used tires, and as a means to find a positive re-use for the hundreds of millions of tires that are discarded each year. Monte Niemi, our founder and president, proposed the idea in the early 1980s. Following several successful road building projects in northern Minnesota, engineering firms found that TDA could perform as well as other lightweight aggregates, and better than conventional materials in several different applications. ​ TDA is currently used not just as a means to recycle tires, but because it has many advantageous engineering properties compared to conventional and lightweight aggregates and fill material. ​ What does the American Society for Testing and Materials (ASTM) say about TDA? ​ The American Society for Testing and Materials (ASTM) has outlined the Standard Practice for Use of Scrap Tires in Civil Engineering Applications (ASTM D6270-20). Type B TDA is defined as “pieces of scrap tires that have a basic geometrical shape and are generally between 3 and 12 inches in size and are intended for use in civil engineering applications.” The full Standard can be accessed here . ​ Does TDA meet regulatory requirements? ​ The U.S. Environmental Protection Agency calls the use of shredded, recycled tires “viable” and “useful”, recognizing they are a cost-effective option in civil engineering projects. The Minnesota Pollution Control Agency (MPCA) has approved and encourages the beneficial use of recycled tires in accordance with state statute and rule . See Regulations . What are the environmental impacts? ​ Typically in the United States, nearly one tire per person is discarded every year (over 5 million in Minnesota alone). The need for recycling tires in secondary markets is essential, as unattended tire piles can hold water and harbor disease-carrying mosquitoes or rodents, and tire fires are dangerous and toxic. Using TDA preserves natural aggregate resources as it can be used as a substitute for sand, rock, gravel, etc., and reduces carbon emissions by lowering trucking volumes. In addition, TDA can be utilized in projects seeking LEED and GREEN ROADS certification . See more about our commitment to sustainability . Does TDA leach unwanted pollutants? ​ Research conducted over the last 30 years by the Environmental Protection Agency, universities and other firms and organizations concludes that TDA has negligible effect on water quality, and leach metals fall below detection limits just a few feet from a TDA fill. ​ EPA-funded research concludes: “The preponderance of evidence shows that TDA (used below the water table) does not cause metals with primary drinking water standards to be exceeded. Moreover, the data shows that TDA is unlikely to increase level of metals with primary drinking water standards above naturally occurring background levels.” EPA Data . ​ Shredded tires don’t break down when not exposed to the sun. The metals iron, zinc and manganese can leach from TDA, but not at levels to have real negative environmental impacts to plant, aquatic or human life. What is the cost of TDA? ​ In the United States, TDA is typically less expensive (sometimes up to 40%!) than its counterpart for a given civil engineering design. We will work with you to make sure you are getting a cost-effective solution! How do I design a project with TDA? We work hard to educate people about benefits, design, and construction practices using TDA. We offer over 30 years of empirical experience for free, and share historic design and construction practices. We’ve conducted hundreds of short (usually 1-hour) TDA Continuing Education training sessions for civil engineering firms, contracting companies, governmental and zoning departments. (You can even obtain CEU credits for attending!) How do I work with TDA? Construction equipment needed for TDA is similar to typical aggregate, such as stone or gravel. Special machinery isn’t necessary! It is important, however, to keep in mind the compressibility of TDA in reaching final grade elevations and TDA compaction. The general rule is that 100 cubic yards TDA loose volume equals 50 cubic yards volume after compaction and compression.. So, if you need to fill a 500-cubic-yard area, you would need 1000 cube yards of TDA. 1 compacted cubic yard = 2 loose volume cubic yards. See Installation . HAVE QUESTIONS? CONTACT US! ​

INSTALLING TDA In civil engineering applications, TDA is usually installed in 18-inch layers. After kneeding and compaction (repeated as necessary until final elevation is achieved), a geotextile fabric may be used to cover TDA. On top of that, 18-24 inches of other aggregate is used to compress the compacted TDA. Then, depending on the project design specifications, the surface can be built as usual. ​ TDA can be easily spread and compacted with conventional construction equipment. Typically, the material is delivered to the job site using walking- floor trailers, and excavators and bulldozers are used to place the material. Once the TDA is spread over the site in lifts, it is compacted with a compactor or bulldozer by running over it several passes. (In some applications, a drum roller is used for compaction.) As these vehicles move over the fill, the pieces tend to interlock, orienting parallel to the horizontal shear plane as they form a snowshoe­-like layer. ​ "Dribbling" of tire pieces is reduced significantly by isolating the equipment spreading the TDA from the equipment moving soil and keeping heavy equipment to the area holding the TDA. (Avoid moving this equipment in and out of other construction areas.) Simple maintenance of equipment such as cleaning tire pieces out of tracks ensures smoother operations, as well. ​ Remember that TDA will have elevation shrinkage when compressed with the 18-24 inches of soil. To achieve the correct design depth following compaction, engineers and designers recognize that approximately 50% more loose volume TDA is required compared to conventional aggregate. Request Installation Guide