Environmental Statement volume 4 - Chiltern Evergreen3

F4DEVELOPMENT ACTIVITIES AND IMPACT IDENTIFICATIONF4.1 INTRODUCTIONGeneral development impacts are described below from Sections F4.2.1 toF4.2.5. The impact identification process involved a review of the Europeansites’ (and SSSIs) conservation objectives to identify key sensitivities /vulnerabilities and to link these with potential impacts that could arise fromdevelopment activities through the Scheme.The impact/sensitivity matrix (Table 4.1) displays these links. Potentialimpacts from the implementation of the Scheme that could have likelysignificant effects on the qualifying interests of the European sites are thenidentified and assessed in Chapter 8 of the Environmental Statement.F4.2 POTENTIAL IMPACTSF4.2.1Disturbance / DamageThis category covers physical damage caused by construction activities,operational activities, increased access or erosion which could result in a lossin area of habitat. A small number of the designated sites are partially withinor adjacent to the Scheme boundary and therefore construction activities mayhave the potential to damage or disturb the interest features. Therefore thispotential impact is included within Table 4.1.F4.2.2Air Pollution - Nutrient EnrichmentAn addition of nutrients can cause eutrophication of habitats. This situationcan arise from sources such as exhaust emissions and traffic pollution fromdevelopment. This, in turn, can lead to direct pollution damage, changes invegetation, directly affecting protected habitats and species of flora, orprotected species dependant upon the vegetation.The operational phase of the development could give rise to air pollutionthrough increased exhaust emissions from trains. Therefore this potentialimpact is included within Table 4.1.F4.2.3Water Pollution / Hydrological Change – Changes to Hydrological Regime,Nutrient Enrichment from Run off / SiltationThis category covers changes to botanical composition of habitat reliant on abalanced hydrological regime which in turn is dependent on specific groundand surface water movements, drainage and flooding. Changes to groundand surface water movements, drainage and flooding are aspects which couldin theory be affected by drainage from development or any run off from theworking areas via surface or ground water links.ENVIRONMENTAL RESOURCES MANAGEMENTF15CHILTERN RAILWAYS