A review of the development of regional sludge treatment centres and a baseline characterisation of Irish sewage sludges

This Study assessed the development of sludge treatment and reuse policy since the original 1993 National Sludge Strategy Report (Weston-FTA, 1993). A review of the 48 sludge treatment centres, current wastewater treatment systems and current or planned sludge treatment and reuse systems was carried out Sludges from all Regional Sludge Treatment Centres (areas) were characterised through analysis of selected parameters. There have been many changes to the original policy, as a result of boundary reviews, delays in developing sludge management plans, development in technology and changes in tendering policy, most notably a move to design-build-operate (DBO) projects. As a result, there are now 35 designated Hub Centres. Only 5 of the Hub Centres are producing Class A Biosolids. These are Ringsend, Killamey, Carlow, Navan and Osberstown. Ringsend is the only Hub Centre that is fully operational, treating sludge from surrounding regions by Thermal Drying. Killamey is producing Class A Biosolids using Autothermal Thermophilic Aerobic Digestion (ATAD) but is not, as yet, treating imported sludge. The remaining three plants are producing Class A Biosolids using Alkaline Stabilisation. Anaerobic Digestion with post pasteurisation is the most common form of sludge treatment, with 11 Hub Centres proposing to use it. One plant is using ATAD, two intend to use Alkaline Stabilisation, seven have selected Thermal Drying and three have selected Composting. While the remaining plants have not decided which sludge treatment to select, this is because of incomplete Sludge Management Plans and on DBO contracts. Analysis of sludges from the Hub Centres showed that all Irish sewage sludge is safe for agricultural reuse as defined by the Waste Management Regulations {Use of Sewage Sludge in Agriculture) (S.I. 267/2001), providing that a nutrient management plan is taken into consideration and that the soil limits of the 1998 (S.I. 148/1998) Waste Management Regulations are not exceeded.

The assessment, management and ecological significance of Irish hedgerows

The vast network of hedges in Ireland provide habitats of great importance to the wildlife of the country, yet surprisingly enough, only very limited survey work has been carried out on our hedgerows in the past. Now with the implementation of the new Rural Environmental Protection Scheme, farmers will be paid to manage their hedgerows in such a way as to make them into increasingly attractive wildlife habitats. However, hedgerow management expertise seems to be somewhat lacking in Ireland and we must draw upon the knowledge of our neighbours in the E.U. where quite an amount of research has been carried out on this subject. The aim of this study is to present the relevant aspects of the research for the benefit of the people who will be involved in the administration of the Rural Environmental Protection Scheme and to anyone else involved in hedgerow management.

Investigating the long term planning framework for the Galway Bay community from climate change.

This research looked at the scientific evidence available on climate change and in particular, projections on sea level rise which ranged from 0.5m to 2m by the end of the century. These projections were then considered in an Irish context. A review of current policy in Ireland revealed that there was no dedicated Government policy on climate change or coastal zone management. In terms of spatial planning policy, it became apparent that there was little or no guidance on climate change either at a national, regional or local level. Therefore, to determine the likely impacts of sea level rise in Ireland based on current spatial planning practice and policy, a scenario-building exercise was carried out for two case study areas in Galway Bay. The two case study areas were: Oranmore, a densely populated town located to the east of Inner Galway Bay; and Tawin Island, a rural dispersed community, located to the south east of Inner Galway Bay. A ‘best’ and ‘worse’ case scenario was envisaged for both areas in terms of sea level rise. In the absence of specific climate change policies it was projected that in the ‘best’ case scenario of 0.5m sea level rise, Tawin Island would suffer serious and adverse impacts while Oranmore was likely to experience slight to moderate impacts. However, in the ‘worse’ case scenario of a 2m sea level rise, it was likely that Tawin Island would be abandoned while many houses, businesses and infrastructure built within the floodplain of Oranmore Bay would be inundated and permanently flooded. In this regard, it was the author’s opinion that a strategic and integrated climate change policy and adaptation plan is vital for the island of Ireland that recognises the importance of integrated land use and spatial planning in terms of mitigation and adaptation to climate change.

The vulnerability to pollution and hydrochemical variation of eleven springs (catchments) in the karst lowlands of the west of Ireland

The vulnerability to pollution and hydrochemical variation of groundwater in the mid-west karstic lowlands of Ireland were investigated from October 1992 to September 1993, as part of an EU STRIDE project at Sligo Regional Technical College. Eleven springs were studied in the three local authority areas of Co. Galway, Co. Mayo, and Co. Roscommon. Nine of the springs drain locally or regionally important karstic aquifers and two drain locally important sand and gravel aquifers. The maximum average daily discharge of any of the springs was 16,000 m3/day. Determination of the vulnerability of groundwater to pollution relies heavily on an examination of subsoil deposits in an area since they can act as a protecting or filtering layer over groundwater. Within aquifers/spring catchments, chemical reactions such as adsorption, solution-precipitation or acid-base reactions occur and modify the hydrochemistry of groundwater (Lloyd and Heathcote, 1985). The hydrochemical processes) that predominate depend cm the mineralogy of the aquifer, the hydrogeological environment, the overlying subsoils, and the history of groundwater movement. The aim of this MSc research thesis was to investigate the hydrochemical variation of spring outflow and to assess the relationship between these variations and the intrinsic vulnerability of the springs and their catchments. If such a relationship can be quantified, then it is hoped that the hydrochemical variation of a spring may indicate the vulnerability of a spring catchment without the need for determining it by field mapping. Such a method would be invaluable to any of the three local authorities since they would be able to prioritise sources that are most at risk from pollution, using simple techniques of chemical sampling, and statistical analysis. For each spring a detailed geological, hydrogeological and hydrochemical study was carried out. Individual catchment areas were determined with a water balance/budget and groundwater tracing. The subsoils geology for each spring catchment were mapped at the 1:10,560 scale and digitised to the 1:25,000 scale with AutoCad™ and Arclnfo™. The vulnerability of each spring was determined using the Geological Survey's vulnerability guidelines. Field measurements and laboratory based chemistry analyses of the springs were undertaken by personnel from both the EPA Regional Laboratory in Castlebar, Co. Mayo, and the Environment Section of Roscommon Co. Council. Electrical conductivity and temperature (°C) were sampled fortnightly, in the field, using a WTW microprocessor conductivity meter. A percentage (%) vulnerability was applied to each spring in order to indicate the areal extent of the four main classes of vulnerability (Extreme, High, Moderate, and Low) which occurred within the confines of each spring catchment. Hydrochemical variation for the springs were presented as the coefficient of variation of electrical conductivity. The results of this study show that a clear relationship exists between the degree of vulnerability of each catchment area as defined by the subsoil cover and the coefficient of variation of EC, with the coefficient of variation increasing as the vulnerability increases. The coefficient of variation of electrical conductivity is considered to be a parameter that gives a good general reflection of the degree of vulnerability occurring in a spring catchment in Ireland's karstic lowlands.

Development of a data acquisition system to characterise sustainable energy technologies and to support Web-Based learning (DAQ-WBL)

Driven by concerns about rising energy costs, security of supply and climate change a new wave of Sustainable Energy Technologies (SET’s) have been embraced by the Irish consumer. Such systems as solar collectors, heat pumps and biomass boilers have become common due to government backed financial incentives and revisions of the building regulations. However, there is a deficit of knowledge and understanding of how these technologies operate and perform under Ireland’s maritime climate. This AQ-WBL project was designed to address both these needs by developing a Data Acquisition (DAQ) system to monitor the performance of such technologies and a web-based learning environment to disseminate performance characteristics and supplementary information about these systems. A DAQ system consisting of 108 sensors was developed as part of Galway-Mayo Institute of Technology’s (GMIT’s) Centre for the Integration of Sustainable EnergyTechnologies (CiSET) in an effort to benchmark the performance of solar thermal collectors and Ground Source Heat Pumps (GSHP’s) under Irish maritime climate, research new methods of integrating these systems within the built environment and raise awareness of SET’s. It has operated reliably for over 2 years and has acquired over 25 million data points. Raising awareness of these SET’s is carried out through the dissemination of the performance data through an online learning environment. A learning environment was created to provide different user groups with a basic understanding of a SET’s with the support of performance data, through a novel 5 step learning process and two examples were developed for the solar thermal collectors and the weather station which can be viewed at http://www.kdp 1 .aquaculture.ie/index.aspx. This online learning environment has been demonstrated to and well received by different groups of GMIT’s undergraduate students and plans have been made to develop it further to support education, awareness, research and regional development.