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 differences 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 different. Some of these challenges are covered below.
Noise monitoring against complex requirements
As highlighted above, some of the noise regulations can be quite complex requiring different limits at different times of day, days of the week and for different land uses. Keeping track of permissible levels and your compliance can be a significant challenge.
Quick response required to monitoring
Drilling activities are going on continuously and permits are granted at short notice requiring immediate response. This needs engineers on call 24/7 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 from other sources
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 traffic, a lawnmower, or in some cases, the effect of wind noise on a measurement microphone. This leads to contamination of the measured noise level. It is not sufficient to just measure the noise, it is necessary to determine if the noise came from the drilling rig or not. Measurement of different noise metrics may be allowed, specifically 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 traffic.
Visibility of compliance
Continuous measurement of noise is important to ensure that operations are compliant. However, being compliant is not sufficient, you have to be seen to be compliant for the benefit 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. For a drilling contractor, doing all of the above, while focusing on the core job of drilling, presents a significant, but necessary burden. The risk of not meeting the challenge can be expensive, not just in lost hours from drilling shutdown, but in the cost of establishing additional mitigation measures and possibly, most significantly, in the loss of trust with communities and regulators which could hamper future drilling applications.