**Document:** Technical Note Noise Condition **Application:** 03/01843/B — Extension of existing quarry in an easterly direction for the extraction of mineral reserves. (Full description see file) **Decision:** Permitted **Decision Date:** 2004-04-20 **Parish:** German **Document Type:** report / planning_statement **Source:** https://planningportal.im/a/74882-german-poortown-quarry-extension/documents/1587029 --- # Technical Note Noise Condition TECHNICAL NOTE - POORTOWN QUARRY EXPANSION NOISE CONDITION 21(a) Prepared by: Bureau Verltas Acoustic Technology Author: Bernard Postlethwaite Date: 5th July 2005 Ref: 5637661BCP/24619/1 - 1 INTRODUCTION This technical note is in relalion to Condition 21(a) of the Schedule of Conditions given in the Inspector's report dated 8th April 2005 of the Inquiry held on 19111and 20th January 2005 in connection with the proposed extension to Poortown Quarry. The condition, as phrased. contains an oxymoron which could cause confusion in the future, if not clarified now. This is in the mixed use of Ihe terms "free field~ and ~falfade~when referring 10noise limits. - 2 COMMENTS ON CONDITION 21a The condition, as currently worded reads: "Apart from during blasting operations, noise ernifled from the site shall not exceed 56 dB LA9q(1 hour}(frefl foeJd) when measured 1 m from the faqade of any noise sensitive property. except from the removal of soil and construction or removal of landscape or baffle mounds. at which time noise (rom these activities shall not exceed 70 dB LA9q (1hoot) (free rl8ldJ when measured 1 m from the taqade of any noise sensitive property~. The difficulty arises in mixing up the terms "free field" and "fa<;:ade~levels. The term "free field- means an environment which does not give rise to significant reflection of sound apart from the ground. The distance at which a reflector ceases to be of significance varies according to the size of the reflector and the frequency of Ihe sound in question, but it is often taken to be a minimum distance of 3.5 m away from the fa<;:adeof a property. A "fa<;:ade- noise level is one measured close to the fa<;:adeof the building and typically at a distance of 1 m from it. In accordance with good practice, as given for example in the UK Government's Minerals Planning Guidance MPG 11 (Ref 1) and now replaced by Minerals Policy Statement MPS 2 (Ref 2), all of the calculations which were undertaken for the Environmental Statement for the Poortown Quarry expansion, and which were subsequently given as evidence at the Inquiry were "free field- levels Le. not taking into account localised reflection effects. The Inspector acknowledges in paragraph 137 of his report thai the noise levels prescribed in Conditlon 21a correlate with ~established guidelines" for maximum limits adjusted to take into account predicted levels at noise sensitive property contained in the EIA Volume B Section 8. By "established guidelines. it would be assumed that the Inspector is referring to MPG 11 or MPS 2. As such, it should be noted that the noise limits given in MPG 11 and MPS 2 relate to "free-field" levels. Paragraph 2A.2 of Appendix 2A 01MPS 2, "Understanding Noise~ states: "Noise emissions are measured using sound level meters, which detect and record changes in sound pressure. Integrating meters also perform statistical analysis and descriptors of interest (e.g. LA90. T. LAI!tq. T) can be determined directly from the meter. Noise from any particular source is reffected by any faqade that directly (aces that source. Thus a microphone 1-2 m in front of a building would typically yield a level 3 dB(A) higher than a free-field measurement (i.e. at least 3.5 m away from a faqade). 563766JBCP1246 t 9/1 ## I There are two main reasons for using "free field" rather than "far;ade levels" in setting noise limits. The first is that fa9ade effects can be complex, and can give fise 10 varying degrees of reflection, sometimes greater than 3 dB. The second is that it is usual practice to agree a procedure for verification of a limit at a position or positions that are freely accessible to all parties. In this respect locations are usually chosen that are close 10the property in question bul at public locations, and this would normally be away from the fa9ade of the property. It is suggested that 10avoid any confusion, Condition 21a could be reworded as follows: Suggested amendment to Condition 21a: ~Apart from during blasting operations. noise emitted from the site shall not exceed 56 dB LAeqfl hour) ("&11 field) when measured at least 3.5 m from the fat;ade of any noise sensitive property, except from the removal of soil and construction or removal of landscape or baffle mounds, at which time noise from these activities shall not exceed 70 dB LAeq (I houri l!reft flfJld) when measured at least 3.5 m from the far;ade of any noise sensitive property". Alternatively, if rewording of a condition causes difficultly at this stage, a memorandum of understanding could be drafted and agreed between the relevant parties. It should also be noted thaI a noise and vibration monitoring scheme will shortly be prepared and agreement sought on this with the authorities. Clarification of the intent of the noise limit could also be included in this monitoring scheme. REFERENCES - (1) Department of the Environment, Welsh Office ~Minerals Planning Guidance: The Control of Noise at Surface Mineral Workings. MPG 11 April 1993 - (2) Office of the Deputy Prime Minister ~pranning Policy Statement 2: Controlling and Mitigating the Environmental Effects of Minerals Extraction in England - Annex 2: Noise" --- *Data sourced from the Isle of Man public planning register under the [Isle of Man Open Government Licence](https://www.gov.im/about-this-site/open-government-licence/).* *Canonical page: https://planningportal.im/a/74882-german-poortown-quarry-extension/documents/1587029*