UPDATE: SWANA's report on metal recovery from combustion ash is now available. The report focuses on the potential of recovering metals smaller than 12 millimeters from waste-to-energy bottom ash as well as using it in road construction projects. It studies the Lancaster County Solid Waste Management Authority's partnership with Inashco in Pennsylvania which is expected to increase metals recovery by 46%. The report also looks at a pilot program in Florida's Pasco County that could make 83% of bottom ash available for reuse in construction aggregates.
- An upcoming report from the Applied Research Foundation (ARF) — created by the Solid Waste Association of North America (SWANA) — says that the recovery of metals from combustion ash has the potential to help community recycling programs.
- The report states an estimated two-thirds of metals generated in residential households aren't recycled because they're not part of curbside programs for a variety of reasons. SWANA makes the case that new methods of recovering metals from bottom ash can help divert more than 90% of waste from landfills.
- The report, entitled "Innovations in Waste-To-Energy Ash Management," will be released in September.
The value of WTE ash has been recognized in Europe for many years, where multiple countries use it as an aggregate in concrete or asphalt. As featured in Waste Dive earlier this summer, the practice of mixing bottom and fly ash in the U.S. can be traced back to at least the 1980s. Frank Roethel, a chemical oceanographer from New York, used the material to successfully construct artificial reefs and later a boathouse that is still standing today.
The EPA estimates that much of the residual ash is still being landfilled, mainly due to regulatory and economic conditions, though that has begun to change. In June, Republic Services opened a new ash recovery facility in Washington that will recycle 46,200 tons of ferrous metals and 42,900 tons of non-ferrous metals over an estimated 10-year period. Pennsylvania's Lancaster County Solid Waste Management Authority also recently entered into a long-term ash processing contract with the Dutch company Inashco that is expected to increase the recovery rate from 10.5 to 15.3%.
As highlighted in the ARF report, Florida's Pasco County is doing some of the most interesting work with ash right now. A project that used bottom ash as an aggregate in road construction was reportedly the first of its kind to receive a state environmental permit. The team behind this is now talking with other local counties about opportunities for similar projects and Pasco County is even interested in mining ash from its landfill for new uses.