Noise Assessment Report

04/00807/B - Creation of a facility to accept, crush and screen inert construction waste, Land at the Technical Site, The Old Airfield, Andreas. 0. Index 1. Summary On 18 October noise measurements were taken of a Chieftan 600 Powerscreen, which was found to be approximately 15 dB(A) quieter than the concrete crusher as detailed in my report dated 21 Sept 04. During monitoring it was not possible to measure noise from the Screen at closest residential premises due to noise from Nothern Scrap Metals, which would indicate that a level of 50 dB(A) may be acceptable, at least for short periods, to residents at this location. By calculation I predict that the Powerscreen, with appropriate acoustic screening (earth bunds) and by pointing the screen towards Woodside/Woodcroft Cottages in its least noisy direction, that a level of LAeq, 1 hour of 45 dB(A) could be achieved at the boundary of these residential premises. According to 'Mineral Planning Guidance 11: Control of noise at surface mineral workings', such a limit should prove tolerable to most people in rural areas. It is recommended that waste disposal operations at the site should not commence without an appropriate Waste Disposal License, as this is an offence under section 57 of the Public Health Act 1990. Also, that the issues of dust should be controlled under such a license. Given, in my previous report, an attenuation a measured of 38 dB(A) between the concrete crusher and Woodside/Woodcroft Cottages measurements would indicate a level of 50 dB(A) (88 - 38 = 50 dB) from the Powerscreen and therefore a need to reduce this {{table:514408}} by a further 5 dB(A) by considering siting, use of acoustic barriers and orientation of the powerscreen towards these residential premises. ### 2. Noise Level Measurements and Calculations Noise from a crane at Northern Scrap Metal was 50 dB, consequently by logarithmic subtraction noise from screen could have been as low as 51 – 50 = 44 dB. The noise from the Powerscreen was perceptively quieter than that from the crane at Manx Metals next door and would no doubt be quieter than their car crusher. However, the Powerscreen is likely to be operated for longer periods during the day. By simple calculation I would estimate noise levels from the Powerscreen to be: {{table:514409}} Using Ls – Lr = 20 log Rs / Rr Ls = noise level at distance Rs from source. Rs = distance between source and Ls measurement position. Lr = noise level at distance Rr from source. Rr = distance between source and Lr measurement position. From manufacturer's data attached and using BS 5228: Part 1: 1997 Noise and Vibration control on construction and open sites: {{table:514410}} Attenuation Ks = (25 log10 R/10) – 2 where R is distance from point of interest. {{table:514411}} Calculations indicate that it should be possible to keep noise levels below 45 dB(A) and that the plant should be orientated with the quietest part of the plant in the direction of Woodside, Woodside Cottage and Woodcroft Cottage. ## 3. Noise Limit Criteria Considerations Noise Assessment in Accordance with BS 4142: 1997 Method for rating industrial noise affecting mixed residential and industrial areas. ### Likelihood of complaints: The greater the difference between the rating level and background noise level, the increased likelihood of complaints. indicates that complaints are likely. is of marginal significance. If the rating level is more than 10 dB below the measured background noise level then this is a positive indication that complaints are unlikely. For a rating level of LAeq and background of LA90 this would indicate complaints are likely, but consideration also has to be taken of MPG 11. Mineral Planning Guidance 11: Control of noise at surface mineral workings recommends the following noise limits: 38. In exceptionally quiet rural area where the daytime background noise level is below , a condition limiting mineral operators to a 10 decibel excess over the existing background noise level is likely to be both difficult to achieve and unduly restrictive. It would not normally be appropriate to require a daytime limit below 45 dB LAeq, 1 hour, as such a limit should prove tolerable to most people in rural areas. By calculation, the Powerscreen with an effective acoustic barrier (earth bund) should be able to meet a limit of 45 dB LAeq, 1 hour. Although MPG11 recommends noise limits at the noise-sensitive property, I recommend noise limits at the noise-sensitive premises boundary as people also have a right to enjoy the peace and quiet of their gardens.