RSRL Integrated Waste Strategy - Issue 5- Oct 2012.pdf

NOT PROTECTIVELY MARKED4.4.1.1 Harwell Contaminated Land and Groundwater144. The land and associated groundwater on the Harwell site have been surveyed over anumber of years in order to determine the extent and concentration of contaminated landand groundwater. Results of these surveys are documented and processed using aGeographical Information System (GIS) based records management system developed toenable the systematic collection, interpretation and assessment of associated data. Thesystem is known as IMAGES - Information Management and Geographical EvaluationSystem.145. Operations on the site have resulted in contaminated land liabilities associated with thebuildings, services and open areas. These liabilities continue to be surveyed andremediated to a “no danger from ionising radiation” standard, in line with good practicechemical standards, and conditions suitable for re-use in accordance with sustainabilityprinciples.146. Radioactive contaminated land associated with individual facilities may be present dueto historic spills involving liquids. This contaminated land will be remediated as part of theindividual facility’s decommissioning and site remediation programme prior to final survey forde-licensing. Radiologically contaminated land that lies between facilities on the Harwellsite is either a legacy associated with a facility already decommissioned and removed or anarea where material has been moved from one part of the site to another, such as theMeashill Trenches.147. The main non-radioactive chemical contamination of land is at the Western Storage Area(WSA) which was used for the licensed sorting, treatment and landfill burial of chemicalwastes from Harwell and other laboratories in the period 1965-1996. The disposal ofhazardous chemical wastes into shallow unlined chalk pits resulted in a serious aquiferpollution incident stretching 8 km offsite. The chemical pits were remediated in 2005 andthe resultant chemically contaminated wastes have been removed for off-site disposal atsuitably licensed waste disposal facilities.148. The chemically contaminated groundwater from the WSA has been subject to amonitoring programme since 1989 and pump/treat groundwater containment since 1993.During 2011/12 the Unsaturated Zone Remediation Project completed its work to removeover 3000kg of pollutants from the area. The strategy going forward is to:• continue to pump and treat groundwater using the WSA Groundwater ContainmentPlant until 2025• continue a monitoring programme from 2025 to 2050• continue a programme of “monitored natural attenuation” until the entire plumeimproves to better than drinking water standards149. It is possible that a liability will remain for groundwater from the WSA at the end of thesite restoration programme.4.4.2 WinfrithWinfrith End State150. The Winfrith site will be closed at the Interim End State then passively managed byapplying land use restrictions whilst residual radioactivity decays. After a period of time(envisaged to be decades), the site will reach a condition when it can be de-licensed thende-designated at which pint the land use restrictions will no longer be required.RSRL IWS (Issue 5 – October 2012)40