Environmental Statement volume 4 - Chiltern Evergreen3

D2EXISTING CONDITIONSD2.1 BASELINE NOISEBaseline noise levels have been measured in order to assess the existing noiseenvironment at 23 receptors locations along the proposed route from Bicesterto Oxford. Noise surveys were carried out between June 2 nd and September11 th , 2009. Receptor locations were chosen to identify the existing noiseclimate in areas likely to be most affected by the Scheme. Figures 6.1a to 6.1qshow the noise monitoring locations.D2.1.1MethodologyMeasurements were made of the existing noise environment during the daytimeand night-time in accordance with BS 7445 (1) . The following Class 1sound level meters have been used: Norsonic 116; Norsonic 140; and Bruel and Kjaar 2260.All sound level meters were within their calibration period. Sound levelmeters were calibrated before use, and the calibration levels were checkedafter surveying. No deviation of greater than 1 dB was noted. Noisemonitoring equipment was mounted on a tripod so that the microphone wasin a free-field position approximately 1.5 m above ground level adjacent to thereceptor, except for at the following locations;Cox’s Ground, Oxford (NML 17). Free-field measurements were made fromthe level of the second floor bedrooms using a tall tripod, to preventscreening of the railway by a high wooden fence.William Lucy Way, Oxford (NML 19). Long term unattended free-fieldmeasurements at this location were made from the level of the secondfloor bedrooms using a tall tripod, to prevent screening of the railway by ahigh wooden fence.Southern end of Rewley Road, Oxford (NML 21). Long term unattendedmeasurements at this location were made from a third floor window ofthese four storey blocks of flats, overlooking the railway, at a distance of1 m from the façade. The measurements presented here have beencorrected to represent free-field measurements (by subtracting 2.5 dB).Long term unattended noise measurements were carried out at threelocations. Two locations south of the North Oxford Junction (the southernend of Rewley Road (NML 21) and William Lucy Way (NML 19)), were chosen(1) British Standard (BS) 7445: Description and measurement of environmental noise, Part 1, Guide to quantities andprocedures (2003)ENVIRONMENTAL RESOURCES MANAGEMENTD-2CHILTERN RAILWAYS