Out for a walk the other day, I noticed a couple of old automobile tires leaning against the trash bins at a business. That got me to wondering, what do they do with all those tires? Apparently, discarded tires have long been considered a landfill pest. These tires are often under-recycled. They cannot be land-filled in their original form and are posing a problem for many states. Texas has an estimated 80 million recycled tires sitting in storage. Only 15 percent of the state’s discarded tires are recycled according to the Texas Natural Resource Conservation commission.

The North Texas municipal Water District, which provides regional water, waste-water and solid waste services to cities north and east of Dallas, turned its attention toward this tire supply when it began renovating and recycling a 30-year-old, 140-acre landfill northeast of Dallas. They determined that using the old tires , processed into chips and used in leachate collection systems as an alternative to gravel or sand presented many benefits in the landfill construction.

Shredded waste tires
1. Recycled tires have larger pore spaces than gravel or sand and do not have fine minerals that restrict flow through the collection system and prevent complete removal of landfill liquids.
2. Ease of transportation. The light-weight tire chips are easier to transport and maneuver than gravel or sand. One cubic yard of tire chips weighs approximately 900 pounds; a cubic yard of gravel weighs more than 3,000 pounds.
3.Readily available supply. To construct the first eight-acre section of the landfill, NTMWD used 1.2 million tires, or almost 11,000 tons. Over the next decade, 10 more sectors will be constructed. This project will help diminish Texas’ oversupply of used tires.
4. Cost-effectiveness. By using the tires, NTMWD saved approximately $400,000 in the first sector. The total cost of using tires on both the landfill bottom and side slopes was $812,765. In contrast, using gravel on the bottom and sand on the side slopes would have cost $1,256,025; gravel on the bottom and tires on the landfill’s side slopes would have cost $1,103,725; and sand on both the bottom and side slopes would have cost $1,138,060.
“This landfill now offers several protective barriers to separate the solid waste from the environment,” said Carl Riehn, NTMWD executive director. “We’re not only using recycled products to construct the landfill, but we’re also recycling the landfill itself.”
The NTMWD landfill reportedly is the first in Texas to use this type of leachate collection system. Across the state, other landfill operators are following the district’s lead and applying for permits for similar systems.
This is just one of the things that Texas along with other states are doing to recycle and reuse those old tires.