This document presents a state-of-the-knowledge characterization of the air quality impact of prescribed forestry burning in the Pacific Northwest. Prescribed forestry burning has been shown to be a useful management tool in the Pacific Northwest. Techniques for burning are well developed. Much is known about fire behavior under controlled burning conditions; less is known about emissions. Emissions from prescribed forestry burning in this region cannot be accurately estimated from data presently available. The emission factors reported in the literature vary widely, therefore, this report presents ranges of estimated emissions which may reflect the magnitude of forestry burning emissions. The impact of these emissions cannot be accurately assessed using available dispersion models or air quality monitoring networks. Potential impacts of concern include human health and visibility impairment. The total particulate, hydrocarbon and carbon monoxide emissions from forestry burning are significant and may contribute to exceedance of air quality standards in Washington and Oregon. The impact of prescribed burning can be reduced. Smoke management programs are largely successful in preventing observable smoke intrusions into populated areas; however, the potential for air quality degradation from residual smoke still exists. Alternative burning techniques and alternatives to burning are available. Alternative burning techniques include the use of optimal burn periods, optimal standard techniques and new burning technology. The alternatives to forestry burning include the use of mechanical or chemical treatments, improved harvesting systems, slash utilization and no treatment.

"October 1978." "EPA 910/9-78-052." "EPA contract number 68-01-4144." Includes bibliographical references (176-240). Microfiche.