Stationary Source Control Techniques Document for Fine Particulate ...

1. INTRODUCTION
The U.S. Environmental Protection Agency (EPA) has recently analyzed information on the
health effects of elevated concentrations of respirable particulate matter (PM) in ambient air. This
analysis lead to revisions of the national ambient air quality standards (NAAQS) for PM. The EPA has
also added a new "indicator" to measure respirable PM concentrations. The previous indicator was
PM 10, which is defined as particle matter having a nominal aerodynamic diameter of 10 micrometer
(µm) or less. The additional indicator is based on smaller particles, PM 2.5, defined as PM less than or
equal to 2.5 micrometer in aerodynamic diameter. 1
1.1 PURPOSE OF THIS DOCUMENT
The purpose of this document is to support the development of implementation strategies for
attaining revised ambient standards for PM, based on PM 2.5 and PM 10. This document is a revision of
the EPA's 1982 guidance on Control Techniques for Particulate Emissions from Stationary
Sources. 2 The focus of this document is on the control of PM 10 and PM 2.5 emissions from industrial
sources. This document does not address nonindustrial sources, such as residential wood combustion
and windblown dust, which are covered by separate guidance documents.
Although they account for a smaller fraction of national PM 10 emissions than nonindustrial
sources (see Section 2), industrial sources can have significant ambient impacts. These can be
especially important in urbanized areas which are typically centers of both population and industrial
activity. In addition, PM emissions from industrial sources tend to be concentrated in the smaller size
ranges, increasing their importance in the implementation of a potential standard for PM 2.5.
1.2 OTHER RESOURCES
The EPA has recently developed control techniques documents for a number of nonindustrial
sources of PM emissions. In addition, reports have been prepared assessing the overall levels of
control that could be achieved both in direct emissions of PM, and in emissions of gaseous pollutants
that can react to produce secondary PM. Secondary PM is produced mainly from sulfur oxides (SO x),
nitrogen oxides (NO x), ammonia (NH 3), and volatile organic compounds (VOC). These precursor
gases react with one another and with oxygen and water in the atmosphere to form condensible
compounds. Appendix A gives a summary of control techniques documents and other EPA documents
available to support the development of control strategies for primary PM 10 and PM 2.5 emissions, and
emissions of precursor gases for secondary PM.
1.3 ORGANIZATION
This document is organized in seven sections, including this introduction. Section 2 gives
background information on trends in PM air quality and emissions, projected future impacts of control
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