Odour impact

Some activities and some plants (waste water treatments, waste management, food production, refineries, chemical plants, farming) cause the emissions of substances with disturbing odours, which often cause complaints from the population living close to the plant. It is therefore good practice, both during design and during exercise, to quantify the level of olfactive impact around the plant. The odours are perceived at very low concentrations of the polluting substances. The odour intensity is expressed using the Odorimetric Unit (OU), defined as the concentration of the mixture of substances percieved by the 50% of the exposed population.

Enviroware, from the analysis of the meteorological data and the simulation of the atmospheric dispersion of the odorous pollutants, carried out with internationally recognised dispersion models, determines the intensity and the persistence of the odours. The concentrations, averaged over times of few minutes, are compared with the Odorimetric Unit or with the olfactive thresholds of each single pollutant. At the end of the study it is possible to set up all the actions capable to reduce the odour levels and, therefore, to reduce the population complaints.