Validatie van het atmosferisch verspreidingsmodel Stacks voor stofdeeltjes en endotoxinen uit een pluimveebedrijf = Validation of the atmospheric dispersion model Stacks for particulate matter and endotoxins from a poultry farm

In this study, the atmospheric dispersion model Stacks was validated against measurements upwind of (background), inside (model input), and downwind of a broiler farm isolated in a relatively clean environment near the coast line in the north of the Netherlands. The validation was done for Total Suspended Particles (TSP), fine dust (PM10), endotoxins in the TSP fraction, and gaseous ammonia. The main aim was to gain insight into the effects of barn geometry, heat emission and deposition (especially sedimentation of particles). The model predicted relatively small contributions of the barns to concentrations of PM and endotoxins at the measurement locations downwind from the farm (125-835 m). During the measurement campaign of approximately three weeks, this contribution was not or hardly visible above the background concentration in the field measurements. The model also predicted relatively small contributions of the barns to concentrations of ammonia with a decreasing trend with distance from the farm. De model predicted level and trend in the barn contribution to the ammonia concentration was also visible in the data from the field measurements. The dataset obtained contained to little variation, low and high barn contributions, to allow a proper model validation. Possible explanations for the results are discussed in this report. To gain insight into the reliability of the Stacks model, it is recommended to repeat the present study taking into account the experiences and points for improvement from this work.