f2260f30-5434-48ea-aed4-e062ab69f117 GIS Team Environmental Protection Agency +353-53-9160600 +353-53-9160601 PO Box 3000 Johnstown Castle Estate Wexford Co. Wexford Ireland gis@edenireland.ie http://gis.epa.ie 2023-08-21T14:00:59.489Z ISDI Metadata Profile 1.2 EPSG Geodetic Parameter Dataset EPSG 2009-11-25 http://www.opengis.net/def/crs/EPSG/0/29902 GSI Source Protection Areas IE.GeologicalSurveyIreland.SourceProtectionAreas 2012-01-12T00:00:00 2020-01-16T00:00:00 GE.IE.EPA.GEOL.VECTOR.SDE.GEOL_SourceProtectionAreas Areas surrounding individual groundwater sources are termed source protection areas (SPAs). Two source protection areas are recommended for delineation: Inner Protection Area (SI); Outer Protection Area (SO), encompassing the remainder of the source catchment area or ZOC. Inner Protection Area (SI) This area is designed to protect against the effects of human activities that might have an immediate effect on the source and, in particular, against microbial pollution. The area is defined by a 100-day time of travel (TOT) from any point below the water table to the source. (The TOT varies significantly between regulatory agencies in different countries. The 100-day limit is chosen for Ireland as a relatively conservative limit to allow for the heterogeneous nature of Irish aquifers and to reduce the risk of pollution from bacteria and viruses, which in some circumstances can live longer than 50 days in groundwater.) In karst areas, it will not usually be feasible to delineate 100-day TOT boundaries, as there are large variations in permeability, high flow velocities and a low level of predictability. In these areas, the total catchment area of the source will frequently be classed as SI. Outer Protection Area (SO) This area covers the remainder of the ZOC (or complete catchment area) of the groundwater source. It is defined as the area needed to support an abstraction from long-term groundwater recharge i.e. the proportion of effective rainfall that infiltrates to the water table. The abstraction rate used in delineating the zone will depend on the views and recommendations of the source owner. A factor of safety can be taken into account whereby the maximum daily abstraction rate is increased (typically by 50%) for expansion of the ZOC in dry periods, and possibly to allow for possible future increases in abstraction. In order to take account of the heterogeneity of many Irish aquifers and possible errors in estimating the groundwater flow direction, a variation in the flow direction (typically ±10-20°) is frequently included as a safety margin in delineating the ZOC. In delineating the inner (SI) and outer (SO) protection areas, there are two broad approaches: first, using arbitrary fixed radii, which do not incorporate hydrogeological considerations; and secondly, a scientific approach using hydrogeological information and analysis, in particular the hydrogeological characteristics of the aquifer, the direction of groundwater flow, the pumping rate and the recharge. The SPAs in this dataset are based on scientific, hydrogeological mapping. There are several hydrogeological methods for delineating SPAs. They vary in complexity, cost and the level of data and hydrogeological analysis required. Four methods, in order of increasing technical sophistication, are used: (i) calculated fixed radius; (ii) analytical methods; (iii) hydrogeological mapping; and (iv) numerical modelling. The GSI and EPA use the latter three methods for Source Protection Area delineation for public supplies. Even with relatively good hydrogeological data, the heterogeneity of Irish aquifers will generally prevent the delineation of definitive SPA boundaries. Consequently, the boundaries must be seen as a guide for decision-making, which can be reappraised in the light of new knowledge or changed circumstances. The boundaries of the SPAs are based on the horizontal flow of water to the source and, in the case particularly of the Inner Protection Area, on the time of travel in the aquifer. Consequently, the vertical movement of a water particle or contaminant from the land surface to the water table is not taken into account. This vertical movement is a critical factor in contaminant attenuation, contaminant flow velocities and in dictating the likelihood of contamination. It can be taken into account by mapping the groundwater vulnerability to contamination. Groundwater sources, particularly public, group scheme and industrial supplies, are of critical importance in many regions. Consequently, the objective of source protection zones is to provide protection by placing tighter controls on activities within all or part of the zone of contribution (ZOC) of the source. Groundwater Section Geological Survey Ireland Beggars Bush Barracks Haddington Road Dublin 4 Ireland info@gsi.ie water geology groundwater groundwater quality water quality water geographic groundwater pollution hydrogeology GEMET - Concepts, version 2.4 GEMET 2010-01-13 Geology GemetInspireTheme GEMET 2008-12-05 waterbody groundwater hydrology source protection area groundwater protection schemes subsoil permeability groundwater quality water contamination Environmental Protection Agency EPA 2014-06-23 IE ISO 3166 ISO 1974-12-31 Data is for public use under Creative Commons CC-By 4.0 https://creativecommons.org/licenses/by/4.0/ 50000 environment -10.47472 -6.01306 51.44555 55.37999 2012-01-12T00:00:00 2012-01-12T00:00:00 0 1014 An Ordnance Datum or OD is a vertical datum used by an ordnance survey as the basis for deriving altitudes on maps. A spot height may be expressed as AOD for "above ordnance datum". Usually mean sea level (MSL) is used for the datum. Malin Ordnance Datum Derivation of vertical height or depth (in metres) In the Republic of Ireland, OD for the Ordnance Survey of Ireland is Malin Ordnance Datum: the Mean Sea Level (MSL) at Portmoor Pier, Malin Head, County Donegal, between 1960 and 1969. 5731 EPSG Projection 5731 - Malin Head height Metres Derivation of Altitude OD based on Mean Sea Level, Malin Head 1960-1969 ESRI Shapefile 10.x Groundwater Section Geological Survey Ireland +353-53-9160600 +353-53-9160601 PO Box 3000 Johnstown Castle Estate Wexford Co. Wexford Ireland info@gsi.ie INSPIRE Data Specification on Geology INSPIRE Data Specifications v3.0 2014-04-17 The INSPIRE Directive or INSPIRE lays down a general framework for a Spatial Data Infrastructure (SDI) for the purposes of European Community environmental policies and policies or activities which may have an impact on the environment. false COMMISSION REGULATION (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services INSPIRE Interoperability Regulation 2010-12-08 Level of conformance with the COMMISSION REGULATION (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services false Areas surrounding individual groundwater sources are termed source protection areas (SPAs). Two source protection areas are recommended for delineation: • Inner Protection Area (SI); • Outer Protection Area (SO), encompassing the remainder of the source catchment area or ZOC.