The Arizona Department of Environmental Quality (ADEQ) is successfully employing drone technology to estimate volumes of waste tires at regulated sites more quickly and accurately. At one waste tire collection site where ADEQ needed an accurate count to determine a penalty for unauthorized storage, ADEQ initially estimated the job would take 53 hours. Instead, the agency completed the job with two to three hours of field time and approximately ten hours of analysis.
ADEQ used drones and GIS to estimate volume using spatial analysis, creating a 3D image with much higher resolution for the largest piles so individual tires could be identified. Inspectors counted smaller piles onsite. In addition, ADEQ used historic imagery to show how the waste tire piles had grown from 2012 to 2022.
CalRecycle’s conversion table helped to determine an approximate waste tire count. However, due to the highly varied type of tires onsite and because estimates do not apply well to haphazardly stacked tires and to multiple types and sizes of tires, ADEQ created its own site-specific tire conversion rate. Comparing calculated counts versus inspector counts on eight piles allowed staff to check for accuracy and develop a site-specific volume-to-tire conversion factor. The site-specific rate was then applied to remaining tire piles.
ADEQ shared information on this work via Instagram and at EPA’s National Enforcement Investigation Center Environmental Technical Summit held earlier this year. For more information, contact Kathleen Maltby of the ADEQ Waste Programs Division or Debby Crouse of the ADEQ GIS Team.
