Environmental Statement volume 4 - Chiltern Evergreen3

• records held by the British Geological Survey, the Environment Agencyand the local authorities (to identify both geological information,abstractions in the locality and the current groundwater quality);• Environment Agency water quality and discharge records;• Environment Agency flood maps;• site investigation reports; and• Local Authority private water supply records (if readily available).4.9.3 For contaminated land to exist, a valid contaminant linkage must be present.That is, there should be a source of contamination, a pathway by which thecontamination may migrate and a target where there is “significant harm”, ora “significant possibility” of such harm, being caused; or where there issignificant pollution of controlled waters, or a significant possibility of suchpollution being caused. Should any element of this contaminant linkage notbe present (or severed) then the land may not be regarded as contaminatedland, as defined in Part IIA of the Environment Protection Act 1990(amended).4.9.4 The potential sources and pathways which may be affected by the Scheme willbe identified. The sensitive receptors that may be significantly harmed orpolluted by potential contaminative materials (if present) are considered to be:• groundwater;• surface water;• ecology; and• local residents, maintenance and construction workers.4.9.5 In order to assess the potential nature and spatial extent of contamination onthe Scheme, historical mapping and a desktop study of available informationincluding intrusive investigations will be reviewed. These documents shouldprovide information on the historical uses along the scheme and identify areasof contamination.4.9.6 The following potential impacts will be identified and reviewed with regardto the Scheme:• disturbance of potential contaminated soils and groundwater;• generation of waste materials where excavation is required; and• introduction of construction traffic, with possible associated fuel facilitiesand potential leakages.4.9.7 The potential impacts identified above are most likely to occur duringconstruction when there is a substantial interaction with the land. Duringoperation, interaction is less likely.4.9.8 The EIA process will identify the potentially contaminated waste materialfrom the scheme. In order to ensure that there are no significant residualimpacts from waste from the construction of the scheme the followingmitigation measures will be identified:ENVIRONMENTAL RESOURCES MANAGEMENT 66 CHILTERN RAILWAYS LTD