Tire Derived Aggregate for Stormwater Treatment

Project summary:

Minnesota lakes and streams are becoming increasingly impaired. One contributor is stormwater runoff, in both urban and rural areas. The impact of stormwater runoff is controlled by a variety of factors, including population density, vehicle pollution, road treatment policies, and the percentage of impervious land surfaces. These and other factors influence the variety and amount of pollutants, including heavy metals, nutrients (e.g., phosphorus and nitrogen), and microbial contaminants. The effects these contaminants have on our waterways, soil health, and surrounding ecosystems are variable but are dominantly detrimental.

Discarded auto tires, converted into tire-derived aggregate (TDA), can be used as an effective filter when incorporated in engineered stormwater remediation systems. Early indications suggest TDA systems offer similar hydrologic performance to stone aggregate but improved filtration characteristics. The research team will test TDA systems at the lab-scale to assess their potential to host biofilm formation and the ability to optimize the filtration performance for specific contaminants.

The reuse of discarded tires would significantly decrease the amount of solid waste going to landfill or being incinerated. It would also reduce the demand for stone aggregate required by most remediation systems, which could result in decreased land surface disruption due to quarrying. The use of TDA in place of stone aggregate may also result in more effective best management practices, and therefore cleaner stormwater.