8 AIR AND CLIMATE Introduction

Transcription

1 Table of contents 8 AIR AND CLIMATE Introduction Scope of the Assessment Methodology Assessment Criteria for Air Quality National Legislation and Policy on Climate Change Existing Environment Air Quality Climate Likely Significant Impacts Air Quality Climate Mitigation Air Quality Monitoring Climate Residual Impacts Conclusion

2 8 AIR AND CLIMATE 8.1 INTRODUCTION This chapter describes the potential impacts to the ambient air quality from the proposed Silverbirch wind farm. The construction and operational activities have been examined to identify those that have the potential to impact negatively on air quality. The main potential for deterioration of the local air quality will arise during the construction phase, in particular from: Dust generated during earth works and transportation and importation of fill material, and Exhaust emissions from plant and machinery and construction related traffic. Once operational, there will be no direct emissions to the atmosphere. In fact, in a national, European and global context the proposed development will contribute to an improvement in air quality, by displacing energy that would otherwise have been generated by burning polluting fossil fuels Scope of the Assessment Local Air Quality The scope of this assessment focuses on the likely significant impacts to the existing local air quality. Considering the short duration and temporary nature of the construction works the impact on regional and national air quality will be negligible. The assessment focuses on the construction phase as there will be no emissions to atmosphere once the wind farm is constructed Climate Change Should the wind farm be constructed, any impact on global warming and climate change would be positive. The electricity produced by wind turbines offsets the CO 2 emissions that would otherwise have been generated from fossil fuel powered generators Methodology The methodology to assess the impacts on air quality and climate involved a site visit, determination of baseline air quality, review of construction practices and a desktop assessment of all relevant guidance, best practice and legislation Site Visit Mapping, aerial photography and a site visit identified the nearest sensitive receptors, the land use in the area and the local topography. In addition, existing sources of air pollution were noted. 8-1

3 Desk top Assessment A desktop assessment was carried out and this involved: Review of the thirty year average meteorological data at the nearest synoptic weather station, Identification of sensitive receptors in proximity to the study area, Review of relevant assessment criteria, guidelines and best practice to assess the potential impact of the proposed development on air quality (at sensitive receptors) and climate, Review of the general construction methodology and its potential for dust generation Assessment Criteria for Air Quality Potential pollutants arising from the construction phase will arise predominantly from exhaust emissions and fugitive dust. The statutory instruments, regulations and guidance in place to protect ambient air quality on a local scale are described below Air Quality Standards Regulations These Regulations transpose the Directive on ambient air quality and cleaner air for Europe (CAFE) into Irish law. They introduce a limit value to PM2.5 in addition to the existing limit values for PM10, nitrogen dioxide and oxides of nitrogen, sulphur dioxide, lead, ozone, carbon monoxide and benzene. Table 8-1 Relevant Air Quality Standards (Source -NRA 2011) Table 8-2 Relevant Limit Values for PM 2.5 (Source -NRA 2011) 8-2

4 Guidelines for the Treatment of Air Quality during the Planning and Construction of National Road Schemes, The National Roads Authority (NRA), (Transport Infrastructure Ireland), has published guidance for assessing dust impacts from road construction ( Guidelines for the Treatment of Air Quality during the Planning and Construction of National Road Schemes ). This has been used to determine the potential impacts from the proposed construction site operations. Presented in Table 8-3 is a list of distances at which dust could be expected to result in a nuisance from construction sites for impacts such as soiling, PM 10 deposition and vegetation effects. These distances present the potential for dust impact with standard mitigation in place. Table 8-3. Assessment Criteria for the impact of dust from construction with standard mitigation in place Source Potential distance for significant effects (distance from source) Scale Description Soiling Note PM 10 Vegetation Major Large construction sites, with high use of haul roads 100m 25m 25m Moderate Moderate sized construction sites, with moderate use of haul 50m 15m 15m roads Minor Minor construction sites, with limited use of haul roads. 25m 10m 10m Note: Significance based on the 2005 standard which allows 35 daily exceedences/ year of 50 ug/m National Legislation and Policy on Climate Change The National Policy Statement on climate change (DECLG, 2014) sets out a framework for Ireland to transition to a low carbon and climate-resilient and environmentally sustainable economy by This is based on an aggregate reduction in CO2 emissions of at least 80% (relative to 1990 levels) by 2050 across the electricity generation, built environment and transport sectors. The Climate Action and Low Carbon Development Act 2015 provides for approval of plans by the Government in relation to climate change mitigation and adaptation for the purpose of pursuing this transition and meeting international obligations and targets to 2020 and Ireland has signed up to the United Nations Framework Convention on Climate Change and its Kyoto Protocol. Ireland attended the Lima conference of December 2014, which resulted in the Lima call for climate action. This fed into the Paris Agreement on climate change, which was adopted at the COP21 conference in December 2015 and is due to come into effect in The Paris Agreement is an agreement within the United Nations Framework Convention on Climate Change dealing with greenhouse gases emissions mitigation, adaption and finance starting in the 8-3

5 year The agreement was negotiated by 195 countries and agreed in December 2015 and ratified in October The agreement went into effect on 4 th November The Paris Agreement s central aim is to strengthen the global response to the threat of climate change by keeping a global temperature rise this century well below 2 degrees Celsius above preindustrial levels and to pursue efforts to limit the temperature increase even further to 1.5 degrees Celsius. 8-4

6 8.2 EXISTING ENVIRONMENT Air Quality Air quality in Ireland is generally very good given its location on the western side of the European Continent and our exposure to prevailing winds off the Atlantic Ocean to the west. EU legislation on air quality requires that Member States divide their territory into zones for the assessment and management of air quality. The zones in place in Ireland comprise Zones A, B, C and D. Zone A is the Dublin conurbation, Zone B is the Cork conurbation with Zone C comprising 23 large towns in Ireland with a population >15,000. Zone D is the remaining area of Ireland. The Silverbirch Wind Farm site lies within Zone D. The EPA is the designated competent authority for the implementation of all Irish and EU ambient air quality legislation. It is assisted in its role by the local authorities, and it carries out ambient air quality monitoring, which contributes to what is known as the National Ambient Air Quality Monitoring Network. The EPA manages this monitoring network and is responsible for all reporting to stakeholders which include the public and the EU. The EPA is also the National Reference Laboratory (NRL) for air quality for Ireland. The ambient air quality at the proposed Silverbirch Wind Farm site is likely to be very high and characteristic of the rural environment. There are no significant point sources of industrial atmospheric pollution in the vicinity of the site. Minor contributions of atmospheric pollutants in the area will arise through smoke from open fires, domestic boilers and vehicle exhausts. Levels of sulphur dioxide and oxides of nitrogen at the site are expected to be low and in line with typical rural measurements for those parameters. Dust deposition rates in the vicinity of the site are expected to be typical of agricultural land use carried out in the area, with yearly average dust deposition (expressed as a rate in mass per unit area per day) rates of less than 30 mg/m2/day. Given the separation distances between the wind farm infrastructure and the nearest dwellings, there will be no significant effects beyond 50 m (Table 8-3). 8-5

7 8.2.2 Climate Mean climatalogical data for the 30 year period from 1981 to 2010 for the closest representative meteorological station which is located at Shannon Airport, approx. 60km north of the proposed development is summarised in Table 8-4 below. Table 8-4 Mean and Extreme Climatic Values for Shannon Airport ( ) (Source: Met Eireann) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year TEMPERARTURE ( o C) Average mean daily max mean daily min mean temperature absolute max absolute min RELATIVE HUMIDITY (%) Average mean at 0900UTC mean at 1500UTC SUNSHINE (Hours) Average mean daily duration greatest daily duration mean no. of days with no sun RAINFALL (mm) Total mean monthly total greatest daily total WIND (Knots) Average mean monthly speed max. gust mean num. of days with gales WEATHER (Mean no. of days with ) Total snow or sleet snow lying at 0900UTC hail thunder fog

8 The minimum mean monthly rainfall in the period was 59.2 mm in April and the maximum was mm in October. Average annual rainfall in the period was mm and the greatest daily rainfall was 52.3 mm. Temperature ranges between an absolute minimum of C and an absolute maximum of 30.6 C. Annual mean daily temperatures are 10.7 C with a range between 6.0 C and 16.4 C. The annual average relative humidity ranges from 83.6% for the morning recording period to 71.9% for the afternoon recording period. Over the 30 year return period, the mean daily sunshine was 3.5 hours, with an annual average of 59.8 days with no sun. Annual average wind speeds are 9.1 knots with a mean monthly wind speeds range of 8.6 knots to 11 knots. The maximum gust wind speed was 93 knots, with an annual average of 9.8 days with gale force winds recorded. The annual average number of days with hail is 22 days, fog is 32 days and with snow or sleet is 11 days. 8.3 LIKELY SIGNIFICANT IMPACTS Air Quality The main potential impact of the proposed Silverbirch Wind Farm development on air quality in the receiving environment during the construction stage of the wind farm comprises fugitive dust and vehicle emissions associated with the following activities: Extraction of stone from the 3 no. temporary borrow pits for use in the construction of the wind farm; Earthworks associated with the construction of the wind farm infrastructure; Transportation and unloading of crushed stone around the site; Vehicular movement over potentially hard dusty surfaces such as freshly excavated and constructed access tracks and crane hardstanding areas; Vehicular movement over material potentially carried off site and deposited on public roads. There should be no potential impacts on air quality during the operational phase of the development as there are no emissions to atmosphere. 8-7

9 The movement of machinery, construction vehicles and the use of generators during the construction phase will generate exhaust fumes containing predominantly sulphur dioxide (SO 2 ), nitrogen oxides (NO x ), carbon monoxide (CO), and particulate matter (PM 10 ). However exhaust emissions from construction equipment and delivery vehicles will not have an adverse impact on air quality during the construction phase of the development given the exposed nature of the site, the high levels of dispersion and the limited extent and duration of the works. Given the limited extent and duration of earthworks associated with the construction phase of the development and the mitigation measures to be implemented to control fugitive dust emissions from the site, as well as the distance of most sensitive receptors from the site and the presence of forestry between many of the surrounding residences and the works, it is very unlikely that any will be affected by fugitive dust emissions during the construction stage of the development or that these will have an adverse impact on ambient air quality in the surrounding area. On a national scale the project will have a positive impact on air quality in terms of the reduction of greenhouse gases emissions (GHG) when compared with conventional sources of electricity generation Climate There should be no potential impacts on climate associated with either the construction or operational phases of the development. The scale and nature of the development on the site is such that it does not give rise to the presence of massive structures that may have a local microclimatic effect. As there will be no atmospheric emissions from the site once operational, the development will not give rise to adverse impact on the climate. Wind energy is a renewable resource and does not give rise to the emission or discharge of greenhouse gases or other waste by products. 8-8

10 8.4 MITIGATION Air Quality A Construction and Environmental Management Plan (CEMP) will be implemented for the project and will include appropriate mitigation measures to minimise the potential for fugitive dust emissions during the construction stage of the development. These will include: Use of a water bowser to spray access tracks and crane hardstanding areas during any extended dry periods when fugitive dust emissions could potentially arise; Control of vehicle speeds passing over access roads and crane hardstanding areas within the site; Wheel wash facilities at entrances to site off public road to facilitate removal of any material collected by vehicles passing through the site and preventing its deposition on public roads; Use of appropriately covered trucks for delivery of materials along the public road; Monitoring A provision for dust deposition monitoring will also be included in the CEMP. Fugitive dust emissions will be monitored at locations which will be identified in agreement with Kerry County Council prior to construction, typically at boundary locations. Construction dust levels will be monitored monthly in line with dust deposition guidelines and in the unlikely event of being found to exceed 350 mg/m2/day, mitigation measures will be enhanced. There is no national or EU guideline for dust deposition. In this absence, the recognised guideline for total dust deposition levels is 350mg/m2 /day as detailed in the TA Luft Technical Instructions on Air Quality Control, 27 July Climate Given the lack of potential impacts on climate from either the construction or operation phases of the development no mitigation measures are proposed. 8-9

11 8.5 RESIDUAL IMPACTS Once operational there will be no emissions to atmosphere. The significance of zero emissions in terms of regional and global climatic effects is twofold: 1) Energy generation without GHG emissions contributes positively to national and international policy on reducing potential climate change effects. 2) As wind farms do not emit SO2 into the atmosphere, there is a positive impact in terms of reduction in acid rain precursors. 8-10

12 8.6 CONCLUSION There is the potential for dust nuisance to occur during the construction phase. However, considering the separation distance to nearby dwellings in addition to strict adherence to best practice any impact on local air quality will not be significant. Once operational, there will be no direct emissions to the atmosphere. On a national, European and global context the proposed Silverbirch Wind Farm will contribute to an improvement in air quality, by displacing energy that would otherwise have been generated by burning polluting fossil fuels. The construction of the Silverbirch wind farm would represent a positive impact on global warming and climate change. The electricity produced by wind turbines offsets the CO 2 emissions that would otherwise have been generated from fossil fuel powered generators. 8-11