Environmental staf f in front of noise monitoring screens 3 V iolation of any of these requirements can trigger a fne of around US2000 per day that the breach is present In the UK where shale gas drilling is still in the preliminary exploratory phase noise regulations were imposed as part of planning permission for the exploration site in Balcombe in Sussex granted in 2010 The restriction required that noise levels should not exceed 55dB for nearby residents between 730 am and 630 pm Monday to Friday and not to exceed 42dB at all other times A number of complaints about the noise were received and measurements taken by independent experts indicated that noise levels were nearing the prohibited levels prompting calls for the site to be shut down The exploration company immediately stopped work in order to ft sound baffes to reduce noise levels Noise monitoring challenges Noise monitoring is a relatively common requirement for noisy industry and is usually achieved through the installation of a noise monitoring system However shale gas drilling has a number of important dif ferences which raise particular challenges Firstly it s not permanent noise monitoring usually only being required for the construction drilling and fracking process It frequently relocates to the next drilling site where regulations can be dif ferent Some of these challenges are covered below Noise monitoring against complex r equir ements As highlighted above some of the noise regulations can be quite complex requiring dif ferent limits at dif ferent times of day days of the week and for dif ferent land uses Keeping track of permissible levels and your compliance can be a signifcant challenge Quick r esponse r equir ed to monitoring Drilling activities are going on continuously and permits are granted at short notice requiring immediate response This needs engineers on call 247 with equipment ready to deploy If complaints are received then a very rapid response to commence monitoring at the complaints location is needed within 24 hours Noise fr om other sour ces Permissible noise levels from the drilling activities can be small relative to other noise sources in the community For example a level of 55dB can be much lower than road traffc a lawnmower or in some cases the ef fect of wind noise on a measurement microphone This leads to contamination of the measured noise level It is not suffcient to just measure the noise it is necessary to determine if the noise came from the drilling rig or not Measurement of dif ferent noise metrics may be allowed specifcally the L90 the level exceeded 90 of the time This can be a valid way of assessing drilling noise which is generally continuous and separating it from intermittent noise such as wind or road traffc V isibility of compliance Continuous measurement of noise is important to ensure that operations are compliant However being compliant is not suffcient you have to be seen to be compliant for the beneft of regulation to be understood How you communicate compliance to communities is a major challenge when faced with complex varying limits of technical measures such as decibels Noise Sentinel captur es all the noise data and pr esents it in forms that ar e easy for the compliance manager to understand and compr ehensive enough for r egulators to see compliance Greg Bracci Business Development Manager Bruel Kjr