Kilworth Water Supply Scheme - Geological Survey of Ireland

Table of contents1 INTRODUCTION........................................................................................................................................ 12 LOCATION, SITE DESCRIPTION AND WELL HEAD PROTECTION............................................ 13 SUMMARY OF BOREHOLE DETAILS.................................................................................................. 14 METHODOLOGY....................................................................................................................................... 14.1 DESK STUDY............................................................................................................................................ 14.2 SITE VISITS AND FIELDWORK.................................................................................................................... 14.3 ASSESSMENT............................................................................................................................................ 25 TOPOGRAPHY, SURFACE HYDROLOGY AND LAND USE ............................................................ 26 GEOLOGY ................................................................................................................................................... 26.1 INTRODUCTION ........................................................................................................................................ 26.2 BEDROCK GEOLOGY ................................................................................................................................26.3 SUBSOIL (QUATERNARY) GEOLOGY ........................................................................................................ 36.3.1 River Alluvium................................................................................................................................. 36.3.2 Till (Boulder Clay) .......................................................................................................................... 36.3.3 Depth to Bedrock............................................................................................................................. 37 HYDROGEOLOGY .................................................................................................................................... 37.1 INTRODUCTION ........................................................................................................................................ 37.2 RAINFALL, EVAPORATION AND RECHARGE ............................................................................................. 47.3 HYDROCHEMISTRY AND WATER QUALITY .............................................................................................. 47.4 GROUNDWATER LEVELS, FLOW DIRECTIONS AND GRADIENTS................................................................ 57.5 AQUIFER CHARACTERISTICS.................................................................................................................... 57.6 CONCEPTUAL MODEL .............................................................................................................................. 68 DELINEATION OF SOURCE PROTECTION AREAS ......................................................................... 78.1 INTRODUCTION ........................................................................................................................................ 78.2 OUTER PROTECTION AREA ...................................................................................................................... 78.3 INNER PROTECTION AREA........................................................................................................................ 79 GROUNDWATER VULNERABILITY.....................................................................................................810 GROUNDWATER PROTECTION ZONES............................................................................................. 811 POTENTIAL POLLUTION SOURCES.................................................................................................... 912 CONCLUSIONS AND RECOMMENDATIONS ..................................................................................... 913 REFERENCES............................................................................................................................................. 9APPENDIX 1 GEOLOGICAL LOGS OF THE AUGER BOREHOLES. .................................................... 11APPENDIX 2 HYDROCHEMICAL ANALYSES FOR DOWNING BRIDGE BOREHOLE.................... 11APPENDIX 3 GRAPH OF NITRATE LEVELS AT DOWNING BRIDGE. ............................................... 13FIGURE 1 GROUNDWATER VULNERABILITY AROUND KILWORTH .................................................................... 11FIGURE 2 GROUNDWATER SOURCE PROTECTION AREAS FOR KILWORTH....................................................... 12FIGURE 3 GROUNDWATER SOURCE PROTECTION ZONES FOR KILWORTH....................................................... 13List of TablesTable 1 Matrix of Source Protection Zones at Downing Bridge............................................................................. 8