An on-site survey including proper testing of air, water, and land should be conducted at any given site to determine the actual and potential problems that may be occurring that could cause serious health and safety issues for individuals and for the environment in general. The physical survey is an observation of types of materials, types of storage tanks and other areas, compressed gas cylinders, rusted, corroded, leaking, and bulging waste containers, the physical condition of all containers and substances, and the potential pathways of dispersion of hazardous materials. All health and safety hazards must be listed. Air samples should be taken of various parts of the facility for the presence of explosive atmospheres, reduced oxygen levels, inorganic and organic gases and vapors, hazardous airborne chemicals, dust, and other pollutants. Water samples from groundwater supplies and surface water should be taken to determine if there are any levels of hazardous chemicals or materials in the water. Radiological hazards should be quantified and it should be determined if they are alpha particles, beta particles, or gamma rays. This information is necessary not only for mitigation and control but also for determining the appropriate standard operating procedures to be used, the necessary medical supervision, and the type of personal protective equipment to be used and its limitations. In addition, a determination should be made by industrial hygienists as to the implementation of threshold limit values for chemical substances and physical agents that workers can be exposed to over a period of time compared to the permissible exposure limits which have been established as standards by the Occupational Safety and Health Administration.