Landfill material used for base projects

  • Published
  • By Frank Duncan
  • AEDC/PA
Sometimes what we throw away isn't really trash. 

Take, for example, some of the things that used to end up in the Arnold Engineering Development Center (AEDC) Construction and Demolition (C&D) landfill. Masonry, wood, and scrap metal components once represented a bulk of the material that was buried. 

However, after the implantation of diversion practices, masonry components are used as fill material to support base construction projects; wood components are collected and shredded to produce mulch; and scrap metal is segregated from the waste and sold. 

The result of the diversion practices mean that AEDC presently recycles 60-65 percent of the C&D debris generated at Arnold AFB. 

"More than 7,000 tons of C&D debris is transported to the C&D landfill each year; approximately 3,000 tons of this material, representing 35-50 percent, is buried in the landfill," said Tom Penfold, Aerospace Testing Alliance (ATA) facilities support manager. "Most of the remaining debris is diverted to support landfill structure construction and other base projects. These diversions provide an estimated annual cost savings of more than $30,000 based on meeting fill material requirements." 

For example, one key project last year used asphalt diverted from several parking lot resurfacing projects to repair several gravel access roads near the Woods Reservoir Dam. In another project that will be starting in November, gravel, asphalt and dirt removed as part of a Wattendorf Memorial Highway shoulder maintenance project will be used as fill material along Westover Road.

"We expect to use more than 4,000 yards of material from the Wattendorf project to support a sidewalk construction project from the Arnold Village Community Center to the Wingo Inn," said Billy Waites, 704th Civil Engineering Squadron. 

A recent pollution prevention success story process analysis, which was prepared by the Air Force and ATA environmental functions, determined that if all of the C&D debris or waste were to be disposed of in C&D landfills in the local community, the cost would be more than $325,000 per year. "During the analysis, we found that the operational cost of the current C&D landfill on base is about $181,000 per year," said Mike Hodges, ATA environmental specialist. "Based on these figures, the base saves about $145,000 per year." 

In the analysis, key practices accomplished by the ATA landfill operator Jeff Wooten were identified as being instrumental in achieving these rates.
Customers receive guidance to accomplish initial separation at the job site. Truck loads of C&D debris or waste should then primarily consist of one type of material. 

"We take on the primary task of working with our customers to separate materials as they enter the landfill," Mr. Wooten said. "Loads are also separated at the landfill with the use of heavy equipment and with some hand sorting where it is safe and practical. Material for diversion is stockpiled until it is actually used for diversion purposes, at which time the weights are estimated for reporting purposes." 

Wood waste, including lumber, plywood and pallets, accounts for an average of 180 tons a year. Arnold has a no-cost contract with a local pallet company to recycle reusable wooden pallets. A second contractor provides a trailer for collecting wood waste other than usable pallets and removes the waste for recycling.
Another source of wood waste collected is debris from routine tree removal and limb and brush removal. 

"This material is hauled to a holding area on Horse Barn Road," said Michael Summers, ATA lead equipment operator. "Periodically this wood debris is chipped and removed for recycling by a contactor. Material not taken by the chipping contractor is used around the base as mulch and as a topsoil amendment at the C&D landfill." 

In addition, the ATA Roads and Grounds section has a small chipper capable of handing small materials up to a couple of inches in diameter. In looking at further improvements, the process improvement analysis looked at methods to optimize the current diversion rates from 50 percent to 85 percent. 

"While the base does not own a stone crusher for making gravel out of the masonry material collected, the landfill operator does have equipment available to break down large chunks of concrete to smaller pieces," Mr. Summers said. "A larger capacity wood chipper was also considered in order to handle more wood instead of contracting out the operation. However, the relatively small volume handled by the base would not support the purchase of a larger capacity chipper." 

The analysis did determine that certain actions could be done that may enable AEDC to achieve even greater rates.
Some specific steps include:
· Provide for general awareness education on C&D diversion focused at project managers
· Provide generic contract language on waste minimization to promote C&D diversion
· In coordination with project managers, look at major projects as having the greatest opportunity to maximize C&D diversion activities
"The key challenge is to accomplish these actions while not impacting already tight project budgets," Mr. Hodges said. "These actions will be pursued by the Air Force and ATA as we continue to strive for excellence in meeting our environmental stewardship commitments."