A geotechnical investigation conducted to support construction of an office building in Fairfax County, Virginia, revealed naturally occurring asbestos (actinolite and tremolite) at the project site. An asbestos-bearing rock, known as a greenstone/shist, occurs in the county. The six-story, 26,940 sq m office building required blasting of rock and excavation. To protect public health, the Fairfax County Air Pollution Control Board became interested in monitoring the work site for asbestos emissions. In hopes of maximizing health protection and minimizing liability, the developer chose to develop an asbestos hazard abatement program. The Virginia Occupational Safety and Health Administration advised that regulations oriented toward the asbestos abatement industry should be applied on the site. SCS Engineers adapted requirements from the indoor abatement regulations for use at the outdoor construction site. A respiratory protection program was developed for the construction workers. Hazards were communicated, and workers were trained to use personal protective equipment and were fit-tested with respirators. Decontamination presented special challenges during the early stages of the effort due to lack of water, electricity, and heat. Medical examinations were performed to obtain information on worker health and fitness for respirator use. Where possible, engineered controls, consisting of dust control measures, were used. Air sampling was done to monitor airborne concentrations of asbestos in worker breathing zones and along site boundaries (to protect public health). Detailed records of site activities and air monitoring results were prepared and submitted to the Air Pollution Control Board on a weekly basis.