An emission factor is a representative value that attempts to relate the quantity of a pollutant released to the atmosphere with an activity associated with the release of that pollutant. These factors are usually expressed as the weight of a pollutant divided by a unit weight, volume, distance, or duration of the activity emitting the pollutant (e. g., kilograms of particulate emitted per megagram of coal burned). Such factors facilitate estimation of emissions from various sources of air pollution. In most cases, these factors are simply averages of all available data of acceptable quality, and are generally assumed to be representative of long-term averages for all facilities in the source category (i. e., a population average).
To better support local agencies and regulated businesses when estimating emissions from a source, the District has compiled a series of toxic emission factor profiles for various source types that can be provided upon request. For emission factor requests or questions, please contact the District at HRAModeler@valleyair.org.
