Towards an Optimal Methodology for Enforcement of Odour Problems

In the Flemish Region of Belgium, the Environmental Inspectorate Division (EID) of the Flemish Government is responsible for the enforcement of the environmental health legislation. This legislation obliges plant operators to take all measures to prevent damage and nuisance. This also applies to odour nuisance. However, in the absence of clear criteria regarding the acceptability of odour pollution, the assessment of odour problems remains a subjective issue. In general, the inspector is able to solve the odour problem by using his own findings and to take the appropriate enforcement actions. However, in order to solve more complex odour cases, the EID usually makes use of an odour investigation by an official expert. The main aim of these investigations is to determine whether or not the odour pollution is acceptable for the neighbourhood. For this, tailor-made maximum acceptable odour levels are deduced. This methodology has been explained during the conference ‘WEF/A&WMA Odors and Air Emissions 2006’ in Hartford. Based on the conclusions of such odour investigations, the EID determines its further attitude towards the companies causing the odour nuisance. The EID has a number of administrative and criminal instruments to promote and/or force the plant operator to reduce odour emissions. Usually the plant operator is forced to make an odour control plan with binding and realistic implementation terms. The entire clean-up process is closely monitored by the EID and adjusted if necessary.After ten years of experience with the odour investigation as an instrument for solving complex odour problems, the EID decided in 2006 that the time had come to optimize this methodology. For this, the EID ordered an extensive study by an official expert. Two main questions had to be answered: how to improve the enforcement instrument ‘odour investigation’ technically and how to improve the use of the instrument by the environmental inspectors in order to obtain a maximal result of odour emission reduction. The evaluation and optimization study was finished at the end of 2007.The conclusions and optimization proposals of this study are the subject of this manuscript. The part on the technical improvement of the odour investigation itself will not be discussed in this paper.