Environmental hazards can be found in all types of building construction. When hazardous materials or biological hazards are encountered during the rehabilitation of existing structures, the special circumstances of working on an existing structure may constrain the identification and remediation of the hazards.
This paper examines instances where hazardous materials or organisms discovered during rehabilitation have had a profound effect on the procedures, time, and cost of rehabilitation and repair. Issues that affect the remediation of such hazards, as well as the long-term use of the structure after rehabilitation, are discussed from the point of view of the architect and engineer.
Because hazardous materials and organisms can create special problems for existing structures, procedures need to be developed that address their identification and remediation. Some commonly encountered hazardous materials and organisms include asbestos, lead, and mold. General guidelines also need to be developed for the identification and remediation of substances not typically encountered. These may include polychlorinated biphenyls (PCBs), volatile organic compounds, and other chemical contaminants.
A proposed methodology for the identification and remediation of environmental hazards is presented in this paper. Case studies are used to illustrate experiences with these materials as encountered during preservation and rehabilitation projects. Issues of immediate hazard, both during investigative work and during repair work, and the long-term implications for serviceability of the structure are also discussed.