Most residential and commercial buildings often contain hazardous materials, some of which are easily removed prior to demolition. When these materials reach a construction and demolition (C&D) processing facility, however, they may pose a threat to workers and might contaminate other recovered products, lowering their market value.
The state of Florida, spurred by several of its counties' ban of C&D wastes in unlined landfills, is studying the option C&D recycling at residential, commercial and demolition demonstration sites.
The study's goals are to determine the advantages and disadvantages of recycling on-site vs. at a processing plant. When all three demonstration projects are completed, the state will publish a C&D job-site recycling guide and hazardous building component removal manual. [See World Wastes March 1998, pages 14 & 16 for information on the residential and commercial sites.]
The demolition demonstration project's goal is to guide demolition contractors in removing hazardous components from buildings prior to demolition. The demolition contractors' manual will help identify hazardous materials often found in buildings (see chart on page 10).
For example, lighting ballasts that were manufactured prior to 1979 probably contain Polychlorinated Biphenyls (PCBs). Ballasts produced after this year will be labeled "No PCBs." Also, certain types of light switches, termed "silent switches," contain mercury. Detailed descriptions of these switches, including their manufacturers, will be included.
Auditing a building will be reviewed, noting approximate removal times and techniques. The necessary equipment, including safety devices (e.g. mercury spill kit) will be listed. Appropriate regulations affecting the removal, transportation, recycling and disposal of materials will be summarized. And a list of current vendors that accept the building materials will be noted as a reference for Florida demolition contractors.
One demonstration project was held in July 1997 at Lakewood Elementary School in St. Petersburg, Fla. The 21-room building was being demolished by Standard Demolition, Inc., Tampa. Six workers completed the job, which took approximately 36 hours.
A 30-minute walk-through inspection kicked off the demonstration. Two team members inspected the upstairs while another pair inspected the downstairs. Both sketched a floor layout documenting the locations of hazardous materials. Following the initial inspection, the fluorescent light bulbs, ballasts, emergency lights and exit signs were removed.
It took approximately 30 seconds to remove each light and ballast, including moving the ladder. Of the 245 ballasts that were removed from the school, only nine contained PCBs.
An additional demonstration project on a University of Florida Campus building also was completed. A building audit for hazardous materials was conducted with the contractor. The results were reviewed, while a research team monitored and assisted with the removal process. Removal times were recorded along with the total amount of hazardous building components removed.