Abstract |
A method is presented which simplifies the task of determining the worst- or best-case meteorological conditions for concentrations from a given stack through examination of meteorological parameters versus downwind concentrations and maximum concentrations using tables. The tables of concentrations are indexed in 342 scenarios (or combinations) by fixed stack parameters: physical stack height and buoyancy flux (related to heat emission rate). Physical stack heights from 5 to 300 meters are considered for heat emission conditions ranging from near ambient to very hot. For each scenario, concentrations are calculated for six Pasquill-Gifford stability classes and for wind speeds valid for each stability. In addition to the maximum concentration and the distance to maximum concentration, the tables display concentrations at ten discusses clustered about the maximum, the wind speed adjusted to physical stack height, the effective stack height, and the distance to final plume rise (Brigg's equations). The tables are an easy and quick reference for determing the impact of new or existing pollution sources on ambient air quality for environmental impact statements or other short-term concentrations analysis. The text describes the algorithms used to generate the tables and a listing of the computer program is included as an appendix. |