Odour nuisance in Ireland and the potential use of olfactometry for the control of odours

Odour nuisance in other European countries has led to the development of techniques which employ panels of human assessors for the determination of environmental odours. Odour measurement is not widely practised in Ireland, yet local authorities are frequently in receipt of odour derived public complaints. This dissertation examines the fundamentals of odour nuisance in terms of how we perceive odours, common sources of environmental odours, the principles of odour measurement (in particular the Sutch pre-standard on olfactometry) and the extent to which odour nuisance is a problem in Ireland. The intention is to provide a reference document for use by those interested parties in the country who may be variously involved in policy making, legislative development, enforcement of environmental law or any person who has an interest in odours and the public nuisance they can give rise to. In particular the aim was to provide previously undocumented information on the prevalence of odour nuisance in Ireland, the exercision of the available powers to control odours, and the possible value of odour measurement as part of a regulatory process. A questionnaire was circulated to all local authorities in the country and 82% responded with information on their experiences and views on the subject of odours. The results of the survey are presented in summary and detailed form.

Development of an inspection regime for on-site domestic wastewater treatment systems

The overall purpose of this study was to develop a thorough inspection regime for onsite wastewater treatment systems, which is practical and could be implemented on all site conditions across the country. With approximately 450,000 onsite wastewater treatment systems in Ireland a risk based methodology is required for site selection. This type of approach will identify the areas with the highest potential risk to human health and the environment and these sites should be inspected first. In order to gain the required knowledge to develop an inspection regime in-depth and extensive research was earned out. The following areas of pertinent interest were examined and reviewed, history of domestic wastewater treatment, relevant wastewater legislation and guidance documents and potential detrimental impacts. Analysis of a questionnaire from a prior study, which assessed the resources available and the types of inspections currently undertaken by Local authorities was carried out. In addition to the analysis of the questionnaire results, interviews were carried out with several experts involved in the area of domestic wastewater treatment. The interview focussed on twelve key questions which were directed towards the expert’s opinions on the vital aspects of developing an inspection regime. The background research, combined with the questionnaire analysis and information from the interviews provided a solid foundation for the development of an inspection regime. Chapter 8 outlines the inspection regime which has been developed for this study. The inspection regime includes a desktop study, consultation with the homeowners, visual site inspection, non-invasive site tests, and inspection of the treatment systems. The general opinion from the interviews carried out, was that a standardised approach for the inspections was necessary. For this reason an inspection form was produced which provides a standard systematic approach for inspectors to follow. This form is displayed in Appendix 3. The development of a risk based methodology for site selection was discussed and a procedure similar in approach to the Geological Survey of Irelands Groundwater Protection Schemes was proposed. The EPA is currently developing a risk based methodology, but it is not available to the general public yet. However, the EPA provided a copy of a paper outlining the key aspects of their methodology. The methodology will use risk maps which take account of the following parameters: housing density, areas with inadequate soil conditions, risk of water pollution through surface and subsurface pathways. Sites identified with having the highest potential risk to human health and the environment shall be inspected first. Based on the research carried out a number of recommendations were made which are outlined in Chapter 10. The principle conclusion was that, if these systems fail to operate satisfactorily, home owners need to understand that these systems dispose of the effluent to the 'ground' and the effluent becomes part of the hydrological cycle; therefore, they are a potential hazard to the environment and human health. It is the owners, their families and their neighbours who will be at most immediate risk.