The same thing happens no matter where you exit I-80 in Pennsylvania. Turn left or right at the end of the ramp, travel a few miles, turn again and then maybe once more, and most likely you will find yourself on one of the commonwealth’s myriad dirt or gravel roads. At least that is how you will end up on Diehl Road in Madison Township, Columbia County—take the Limestoneville exit at mile marker 215, travel eastward through the scenic farmland and small communities along state Rte. 254, turn left onto state Rte. 44 in Jerseytown, take a left about a half-mile away and there you are.
Drive along Diehl Road for less than a mile and before long you will come upon a recently renovated section of the road. If time permits, pull your vehicle off to the side and check it out—walk on the new surface and take a good, hard look. It’s worth your time, because this road is different.
If you didn’t really notice anything out of the ordinary don’t be disappointed. On the surface, this new section of Diehl Road doesn’t appear much different from any other dirt or gravel road. The real difference lies under the surface, where an innovative material now serves as the road’s foundation. By using this material, experts believe they have developed a road that is more durable and lasts longer than other unpaved roads, costs less for municipalities to maintain and, more importantly, drastically reduces the amount of sediment that drains into nearby waterways.
What is this innovative new material? Bales of used tires.
Plentiful. . . for now
According to a March 2005 study conducted by the Colorado Department of Transportation, approximately 2 billion scrap tires currently sit in various stockpiles throughout the U.S. Americans generate nearly 280 million additional scrap tires each year, 77% of which are processed and recycled for various uses.
Today, most states regulate the stockpiling and reuse of scrap tires—including Pennsylvania, which implemented its own Waste Tire Recycling Act (Act 190) in 1996. Since then, the Pennsylvania Department of Environmental Protection (DEP) has overseen efforts to stockpile and recycle the 12.5 million scrap tires generated each year in the state and to clean up the illegal tire piles created by profit-seeking individuals and companies before Act 190 took effect, piles that pose serious environmental and public-health hazards.
“For starters, a vast accumulation of tires at one site poses a significant fire hazard,” said Kathleen McGinty, Pennsylvania’s secretary of environmental protection. “Tire piles are also a potential breeding ground for mosquitoes, which are known to transmit the West Nile virus and other diseases. This doesn’t even take into account that these large piles are also a public eyesore.”
Despite the DEP’s remarkable progress since Act 190 took effect, more than 10 million tires remain in illegal tire piles throughout the state. Nearly 6 million of those tires can be found at one location—the Starr Tire Pile, a 14-acre farm located a few miles away from the Diehl Road project in Greenwood Township, Columbia County.
Over the past two years, the DEP has created fire breaks and implemented other safety measures at the state’s largest tire pile. It also has contacted more than 40 businesses that dumped tires at the Starr property and requested that they remove their share of the tires. More importantly, however, the agency has been seeking opportunities to use tires from the Starr Tire Pile as an innovative resource that bolsters the economy while removing a longstanding threat to the environment.
“We wanted to find good, beneficial uses for the tires,” McGinty said. “We felt it was important to start looking at the tires as a resource that provided opportunities to create clean energy and other innovative uses.”
Ultimately, however, the goal remains to clean up the Starr Tire Pile and other sites. “We’re not looking to build new piles and have someone be in business for the next 100 years,” said David Althoff Jr., chief of the DEP’s Office of Energy Policy and Technology Development. “The intent is for the tire piles to be a finite resource for a business.”
About 90 miles west of Diehl Road, on the main campus of Penn State University, sits the Center for Dirt and Gravel Road Studies. Created in 1999, the center provides training and technical assistance to local municipalities throughout the state to help them maintain dirt and gravel roads properly and correct sediment and dust pollution problems associated with those roads. The center also partners with the Pennsylvania State Conservation Commission, the Pennsylvania Bureau of Forestry, the Pennsylvania DEP, the Chesapeake Bay Commission and other agencies on various training and research projects that enable communities and government agencies to have a better understanding of the benefits derived from environmentally sensitive road maintenance.
Unpaved roads are a key transportation link in Pennsylvania, according to center Director Kevin Abbey. Using a geographic information system to track projects completed through the Dirt and Gravel Road Maintenance Program, the center already has charted nearly 20,000 miles of unpaved roads throughout the commonwealth—roads that also are the state’s largest source of sediment pollution.
“Many dirt and gravel roads in Pennsylvania are entrenched to some degree, which means that the surface of the road is lower than the surrounding terrain,” said Abbey. “Frequently, these roads are located right next to a stream or another water source. In terms of road maintenance, traditional thinking has been to get water off the road and discharged into the stream as quickly as possible. When rainwater collects and travels in concentrated volumes on entrenched roads, however, unstable soil, road material and other available sediment from the banks and ditches accumulates and runs into the stream.
“This excess sediment is choking our waterways to death,” Abbey said. “That’s why it’s important to utilize more environmentally sensitive maintenance practices on these important rural roads.”
Baling out a “win-win”
When the DEP announced a grant program designed to “make beneficial use of the millions of tires piled across the state,” Abbey proposed that the center use some of the tires at the Starr Tire Pile as a sub-base for sections of Diehl Road. By doing so, the center could remove and use the tires in a cost-effective manner while raising severely entrenched sections of the unpaved rural road.
Abbey selected Mike Perks of Alternate Aggregate Development, a subsidiary of Pittsburgh-based QuestCo, to supervise the baling process at the Starr Tire Pile. Perks brought a wealth of experience to the project and is a long-time proponent of tire baling—a process brilliant in its simplicity. To make a bale, tires are loaded onto a hydraulic compressor, compacted into 2.5-ft x 4.5-ft x 5-ft bales and bound together using nine-gauge wire. Each bale uses 100 tires and weighs approximately one ton.
“It’s such a simple process,” Perks said. “It’s also cost effective compared with shredding—one baler costs $55,000, while a bare-bones shredder can cost as much as $350,000. That doesn’t take into account the reduced cost of materials needed for compacting. In typical construction, you usually need to compact the road after every 6 to 8 in. of surface; with bales, you get 30 in.”
Working around the clock, Perks’ crews baled 350,000 tires in less than three months. “By the time we set up the site [in May 2006] and had all three compressors running, we were able to produce 300 bales a day,” he said.
Approximately 206,000 of the tires were used for the Diehl Road project; the rest will be stored as inventory for future projects. “I know that, if given the chance, we could get to the point that we could process a quarter-million tires a month,” Perks said. “In 24 months, we could have the Starr Tire Pile fully abated.”
Perks relishes the opportunity to be “one of the cogs in the wheel that takes a liability and turns it into a bona fide resource.” He also appreciates having a chance to involve local residents in the project—all 38 of his employees at the Starr Tire Pile live in the area.
“Once I got up here and met the people from the community, I wanted to involve them in the project,” Perks said. “It’s a local problem, and the people who live here are invested in resolving the problem. It creates a neat dynamic.”
The road to success
The center chose Diehl Road as the project location specifically because of its proximity to the Starr Tire Pile. The tire bales could easily be placed on flatbed trucks and delivered to the project site in less than an hour. After initial prepping of the road sections, crewmembers from Bloomsburg-based High Excavating used a log truck’s grappling hook to hoist the bales from the flatbeds, placed them five wide on the four sections of Diehl Road selected for the project and secured them in place. The crew also built drainage structures into the road base so that sediment-bearing runoff could be dispersed into stable, vegetated areas of adjacent land instead of nearby streams.
Once the tire bales were arranged, bottom ash—a granular incombustible coal byproduct similar to sand—was used to fill the voids between the tires, and shale was used to shape the surface of the road into its desired crown. The final layer of the road was then put in place using a driving surface aggregate (DSA), a crushed stone mixture developed at Penn State specifically to reduce dust, maximize packing density and produce a durable road surface that performs better than conventional aggregates.
According to Abbey, one of the highlights of the project was the opportunity to use local resources for every phase.
“First and foremost, obviously, were the tires from the Starr Tire Pile site,” Abbey said. “The bottom ash used as fill was donated by PPL’s Montour Plant, which is a coal-fired power plant located just two miles from the project site. The stone used to produce the DSA came from a quarry in nearby Limestoneville, while the shale came from along Diehl Road.”
The entire process to rebuild the four sections of road took about seven weeks and used 2,066 tire bales—more than 206,000 tires—on approximately 0.5 miles of road. To put that in perspective, that means the entire Starr Tire Pile could, in theory, be eliminated by using the 6 million tires at the site to rehabilitate just under 12 miles of severely entrenched roads.
The result is a roadway that Abbey and Perks believe not only greatly reduces serious environmental and public-health concerns, but also save municipalities a great deal in terms of maintenance costs.
“The tire bales are a high-performing aggregate that will outperform rock,” Perks said. “In terms of insulation, the bales have an R-79 value, which means they provide a great deal of frost protection. They also provide much better drainage capabilities than other fill. These two factors alone mean that the amount of maintenance local road crews will perform on those roads will be dramatically reduced for years to come.”
The next steps
Now that the Diehl Road project has been completed, the center will monitor the raised sections to assess their structural stability and gauge the reduced amount of sediment spilling into nearby streams. Results so far have been quite favorable.
In fact, the bales were put to the test even before the driving surface was in place. In mid-June, Pennsylvania was hit with several days of torrential rains. Columbia County was one of the worst-hit places in the state, with the Susquehanna River swelling to levels that had not been recorded since the remnants of Hurricane Agnes roared through the state in 1972.
According to Dave Shearer, a field-operations specialist with the center, roads were flooded throughout the county, and surface material from other dirt and gravel roads washed across paved road surfaces. However, while monitoring the Diehl Road project during the storms, Shearer noted that pipe installations were functioning properly, no ruts had formed in the recently applied surface material and virtually no erosion existed on the tire bale areas.
“Drainage from the recently installed under drains ran as clear as water coming out of the hose,” Shearer said.
Looking ahead, the center plans to continue working with the DEP to identify other Pennsylvania dirt and gravel roads where the use of tire bales would be beneficial and perhaps explore projects that utilize both tire bales and tire shreds.
“There is room to grow—that is sort of chapter two of the project,” Althoff said.
For now, however, everyone involved with the Diehl Road project is pleased with the outcome to date. “We are thrilled with the work that the Center for Dirt and Gravel Roads has done on this project so far,” Secretary McGinty said. “It’s truly a beneficial use of these tires.”