Diffusion estimation for small emissions. Preliminary report

A simplified approach is presented to the calculation of ground level concentrations of effluents from small industrial and fuel burning installations. It is intended to serve as a first approximation to a very complex process. Because each stack, building, and terrain configuration is different, actual ground concentrations may frequently differ from the values calculated here by a factor of two. Nonetheless, this procedure should be useful for determining whether ambient air quality standards are likely to be met, exceeded, or only marginally obtained. It also predicts the locations where the highest and most frequent ground concentrations are likely. Sampling at several such locations is very advisable, unless the predicted concentrations are quite low. In addition, consultation with a specialist in air pollution meteorology may be desirable, especially in marginal or unique situations. The procedures given here were designed especially for source heights of less than 100 m; some of the simplifications made are not valid for large emissions. In the few cases where more than arithmetic formulas are necessary, simple nomograms are provided.