Tens of thousands of temporary wooden buildings from the World War II era, consisting of more than 50 million square feet (sf) of floor area, await removal from numerous U.S. military installations. Wood coated with lead-based paint (LBP) makes the removal and disposal of debris from these buildings expensive and also consumes rapidly shrinking landfill capacity. In California, more than 40,000 wooden buildings must be removed from military sites. Wrecking and landfill disposal is the common building removal method; reuse or recovery of the LBP-coated wood is seldom attempted. Removal of the LBP from wood waste could reduce the burden on landfills by 60–75%. Recovered wood could be reprocessed to make high-quality, revenue-generating wood products such as flooring, siding, paneling, and trim. Much of this old-growth lumber would be valuable in the antique architectural millwork market.
This project demonstrated a process designed to efficiently reclaim construction materials from obsolete buildings in order to recover their economic value instead of discarding them into a landfill. The objective was to validate the effectiveness of an innovative, environmentally compliant building deconstruction process and woodwork-milling mobile unit (MU) designed to economically and safely reclaim vintage exterior siding and dimensional lumber coated with LBP. In addition to deconstruction, remanufacturing operations, and debris processing, the demonstration encompassed marketing the recovered wood products, evaluating waste-reduction performance, and estimating the cost-effectiveness.
The total building removal cost was originally projected to be $12/sf of building, but the actual cost was $15.49/sf. It had been estimated that each building could be removed in 6 working days, but the contractor spent an average of 8 work days per building. The MU’s production rate exceeded the estimated 9,000 linear feet (lf) of painted siding per day and achieved an average output of 11,240 lf/day. Quality expectations for the planed output were met or exceeded. Waste reduction of 60% was initially expected, but the actual figure was 80%. The sale price of the reprocessed lumber was lower than expected but reasonable.
Safety precautions for airborne lead and residual lead in the processed wood were effective, and actual measured concentrations were far below any threshold or action levels. No accident reports were filed, but two incidents of contractor personnel stepping on nails were recorded. The common practice of wearing stainless steel sole inserts would have prevented these injuries.
Overall, MU performance met expectations. Building removal costs above the projected estimate resulted from certain cost-ineffective operational decisions by the contractor and the resolution of a contractor reimbursement issue.
The results of this demonstration enable both the public and private sectors to evaluate the technology in comparison with their own scales and capabilities. The Army installation Directorate of Public Works (DPW) must consider the cost of the technology and its effectiveness in reducing the volume of wastes needing to be trucked to hazardous waste landfills. Responsible personnel will have to decide whether enough lead-contaminated materials will be generated to warrant acquiring a suitable planing machine or whether contracting for the services would be more appropriate. Installation management will also need reliable projections of disposal cost avoidance and a realistic assessment of whether any significant amount of revenue will accrue from the marketing of value-added products made from the recovered wood. When contracting for services, the DPW must be sure to hire contractors with expertise in building deconstruction and materials reclamation in order to fully meet the Army’s facility removal needs and budgets. The contractor must possess specific technical capabilities, operational proficiencies, and marketing insight necessary to cost-effectively deconstruct a building, efficiently separate worthless debris from valuable feedstock, and identify profitable markets for the reprocessed wood.