European countries already have caught on to what the United States is just learning: ash from waste-to-energy (WTE) plants has many beneficial uses.
Germany, France, Denmark and the Netherlands use more than 60 percent of the coarse bottom ash generated by their WTE plants (see chart on page 18) in road base, highway sound barriers, embankments, parking lots, bicycle paths and concrete and asphalt products.
This country, on the other hand, makes far less use of its substantial ash resource. Currently, of the 7 million tons of ash produced from the 28 million metric tons of trash processed annually in U.S. WTE facilities, only 7 percent is used. The rest is landfilled.
"Burying WTE ash may be a major missed opportunity for effective waste management," said David Gatton, the U.S. Conference of Mayors' senior environmental advisor. He notes that project economics are generally more favorable in places that do not have a local aggregate source and for WTE plants that must pay offsite landfill costs because they do not have onsite disposal capability.
In addition to the extensive European experience in WTE ash use, numerous U.S. projects demonstrate excellent ash applications:
*American Ash Recycling Corporation (AAR), Jacksonville, Fla., built a 110-ton-per-hour ash recycling facility for the Metropolitan Government of Nashville and Davidson County, Tenn. The AAR facility recovers nonferrous as well as ferrous metals from the ash and also processes previously generated ash reclaiming landfill space.
*In Rochester, Mass., the SEMASS Resource Recovery Facility manufactures an engineered, granular product produced from its facility's bottom ash. In 1994, it produced 29,000 metric tons of the product while recovering 3,600 metric tons of non-ferrous metals and 20,400 metric tons of ferrous metals.
*The city of Commerce, Calif., has been using ash from its WTE plant for five years. So far, more than 100,000 tons of ash has been used for road base at the landfill and more than 8,000 tons of ferrous metal has been recovered in the process. For the last two years, the city has not had to dispose of any ash.
*Wheelabrator Environmental Systems has developed and patented an ash stabilization process which it has marketed since 1987 and advertises as the most widely-used in the nation.
*Rolite Inc., Wayne, Pa., uses a cement-based stabilization process to turn combustion ash into small, ash-cement balls. The product has been evaluated for landfill use as daily cover, gas venting, drainage layers and for structural fill.
*Beneficial Ash Management of Morrisdale, Pa., uses ash from coal- fired power plants to create a cement-like material or grout for "capping" strip mine reclamation sites with impermeable barriers to prevent acid mine drainage. Now the company has established a sister company, Municipal Ash Management, to make similar grouts from WTE ash.
*The state of Florida has certified that bottom ash from Tampa's McKay Bay Refuse to Energy Facility is a suitable material for road construction, not subject to regulations for waste materials. The state also has approved a soil cement substitute made from ash from the Hillsborough County, Fla., WTE facility.
*The State University of New York at Stony Brook built a boathouse of hollow masonry blocks made from WTE ash and portland cement. Thorough testing found that the blocks did not release environmental contaminants and performed well structurally. The university and others also have demonstrated the suitability of ash products for artificial reefs or erosion control.
The National Renewable Energy Laboratory (NREL), Golden, Colo., a national laboratory of the U.S. Department of Energy, is co-sponsoring a series of five studies on WTE ash use. For example, in Laconia, N.H., bottom ash was substituted for rock in an asphalt mixture used to resurface a federal highway. A second study found no adverse environmental consequences of storing WTE ash in exposed piles prior to mixing with asphalt for paving the entrance to an industrial park in Elizabeth, N.J.
One of two NREL studies in Virginia will mix WTE ash with portland cement to build containers for "pop-up" railroad-crossing barriers. The other will examine the environmental consequences of using blocks made from ash and phosphate cement for revetment walls for beach erosion protection. Finally, the city of Honolulu is testing substitution of WTE ash for soil in landfill maintenance.
Public agencies, private firms and WTE plants can benefit from ash use. It pays off in many ways: saved landfill space, less expensive road construction material, reduced trucking of WTE ash or construction aggregate and enhanced recycling.
For more information, contact: Waste Management Program, NREL, 1617 Cole Blvd., Golden, Colo. 80401-3393. (303) 275-2915. Or, contact: The Integrated Waste Services Association at (202) 467-6240.
Fiscal The Allison Transmission Division of General Motors, Indianapolis, sold 123,000 medium- and heavy-duty automatic transmissions in 1996 which generated sales revenues of $918 million. Last year also saw an improvement in off-highway and military transmission shipment.
Grant The California Integrated Waste Management Board, Sacramento, has awarded $3 million in grants to 34 local governments to establish and expand programs to keep household hazardous wastes out of landfills. The grant will enable Californians' to remove 20 million lbs. already disposed.
New Agent Mid-Atlantic Plastic Systems Inc., Roselle, N.J., has been appointed the U.S. Agent for Julien Environmental Technology - a manufacturer of recycled plastic lumber molding machines and recycled plastic pallet molding machines.
New Facility Waste Control Specialists, Abilene, Texas, has opened a new hazardous waste facility in Andrews County, Texas.
New Office Environmental Risk Limited, Bloom-field, Conn., has opened a Southeast regional office. The address is 1132 Hemingway Ln., Roswell, Ga. 30075. (770) 643-6504. Fax: (770) 643-6507.
New System RRT Design & Construction Corp., Melville, N.Y., announces the construction of a municipal solid waste recycling processing system at the Sumter County Processing, Recycling and Composting Facility in Sumterville, Fla.
People American Disposal Services Inc., Burr Ridge, Ill., a regional, integrated, non-hazardous solid waste services company, has named Stephen P. Lavey as its vice president and chief financial officer. Larvey replaces Scott Flamm.
The Trucking Information Services Division of the Eaton Corp., Clemmons, N.C., has appointed two new sales managers: Jim Scales and David Rust.