Client:  US Army Corps of Engineers Construction Research Engineering Laboratory
Waste treated:  Deconstruction materials contaminated with lead based paint
Project initiated:  October 2005
Project completed:  March 2007

Project goal: Design, build and demonstrate full-scale transportable system for concentrating, recovering and recycling lead from deconstruction materials contaminated with lead based paint

ARI recovered and reused approximately 24,000 lineal feet of lumber painted with lead based paint from WWII-era military buildings. The used lumber was collected by ARI and processed to simultaneously remove lead based paint (LBP) and to produce value-added lumber products and a combination of lead and paint shavings.

ARI processed the shavings to produce a product with lead concentrations high enough to recycle the lead in a lead smelter.  The thermal process reduced the volume of the shavings by 95%, their weight by 90% and resulted in a product exhibiting lead concentrations between 23% and 30%.  This material was accepted by a lead recycler for re-processing.

Air sampling showed that the measured exposures of workers to lead were all below established Occupational Safety and Health Administration (OSHA) Permissible Exposure Limits (PEL’s) and the American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Values (TLV’s).

The results of the combined efforts of the Army and ARI clearly show that recovery, reuse and recycling of LBP lumber is not only responsible and advantageous from an environmental perspective, but is also technically and economically achievable.  ARI’s portion of the project has shown that lead can be safely removed from lumber to produce a value-added product and that the by-products containing the lead can be further processed safely and economically to reduce their volume and concentrate the lead into a recyclable form.  This process significantly reduces the quantities of materials that would otherwise undergo land disposal and diverts toxic lead from disposal altogether thus reducing the risk of future spread of contamination in the soil and ground water.

The thermal process uses bio-fuels and is self-sustaining from an energy standpoint.  Stack emission tests show that the process is clean and does not represent a hazard to human health and the environment.