There are about 600,000 to 700,000 producing oil and gas wells and about 800 natural gas processing plants in the United States. The field separation equipment serving these wells and the natural gas processing plants emit pollutants to the atmosphere. In 1971, an estimated total of 7,000 to 18,000 tons per day of hydrocarbons, about 20,000 tons per day of sulfur oxides, and about 52 tons per day of sulfides (as H2S) were emitted. It is estimated that 90 % of the field processing equipment has adequate emissions control. Technology is available for 100% control; however, conomics are not favorable for recovery of hydrocarbon losses from small production fields in remote locations. Information is presented on the processes used in producing crude oil and natural gas, the location and production rates for the existing production facilities, applicable air pollution control regulations, the processes used in reducing air pollution from oil and gas processes, and methods for testing and analysis of air contaminant emissions. (Author) Portions of this document are not fully legible.