A standing wave in stable drainage flow induced by a small industrial facility

A small town close to a lead/zinc smelter was experiencing unusually high concentrations of sulfur dioxide during certain drainage flow conditions. The episodes occurred in situations where the buoyant plume rise should have been sufficient to eliminate any excessive ground level concentrations resulting from building wake effects. A field study was initiated using visible oil fog, tracer gas releases, and constant volume balloons. The resulting data revealed that a standing wave was being induced in the flow across the smelter bringing pollutants from as high as 150m agl down to 30m agl over the nearby town. The existence of the wave is attributed to the combined effects of the smelter buildings and the thermal forcing supplied by smelter operations. Data are presented characterizing the wavelike disturbance and documenting the meteorological conditions under which it occurs. A comparison is made between the simulated pollutant impacts using the tracer gas data and model predictions using the Industrial Source Complex dispersion model.