In this 3 part article, Acoustic Consultant Teli Chinelis discusses environmental noise monitoring and the steps you should take when conducting one.
This first part concentrates on the assessment of noise impacts.
The Frontiers Report published by the UN Environment Programme (UNEP)[1] in February 2022 identified noise pollution as one of three looming environmental issues (alongside wildfires and disruptive timing of life cycles) that merit attention and action from governments and the public at large. As such, control of noise pollution is a significant component of sustainable development.
In most noise pollution matters, Environmental Noise Monitoring is an essential part of the process and this may relate to new industrial, infrastructure, commercial and residential developments, planning, licensing and dispute resolutions.
Environmental Noise Monitoring is usually required to:
1 make a record of the levels and sources of prevailing ambient/background noise around a proposed site, so that appropriate noise criteria can be recommended for noise emitted from a completed development;
2 quantify the levels of environmental noise incident upon proposed building façades so that the sound insulation requirements can be established;
3 calibrate a computer 3D noise map model;
4 investigate noise complaints;
5 understand noise trends (whether noise levels decrease or increase over time);
6 comply with a requirement (e.g. IPPC[2], planning or licensing condition);
7 quantify the emissions from noise sources to allow assessment/modelling.
Assessment of Noise Impacts
The science of Acoustics is often called “black” art, and this may be due to the lack of a clear relationship between sound levels and human reaction and no clear definition of what constitutes an unacceptable impact or a significant effect. As such, great professional care is required in order to link monitored noise levels with the effects on humans (and these include physiological as well as behavioural effects). However, noise can be an important contributor to other environmental effects acting either directly, indirectly or in combination. For instance, noise may disturb wildlife, alter the character of the landscape, and air overpressure cause structural damage.
Noise impact assessments are complex and can vary greatly with every site needing a bespoke solution. There is a dearth of specific guidance on how to undertake a noise impact assessment and whilst relevant guidance is available, it has not been specifically developed to assist with the process of undertaking a noise impact assessment. The process of a noise impact assessment is an iterative process in which there are multiple feedback loops. This means that while there is a series of commonly accepted and well-understood steps, their application will vary between individual assessments.
In the UK, planning and noise impact assessment work within a complex land use planning decision-making process. Planning attempts to mediate between conflicting interests in the use and development of land.
UK planning is a complex system which is presently defined by:
- Legislation:
– TCPA 1990, Planning Act 2008, Localism Act 2011, Transport and Works Act 1992, Scotland, Wales, Northern Ireland;
- Regulation and Orders:
– EIA Regulations, Infrastructure Planning EIA Regulations 2009, Scotland Regulations, 2011 etc.;
- Judicial and appeal precedence; and
- National policy and advice:
– NPPF, NPS and Planning Practice Guidance, NPF, PPW, SPSS;
– Local policy and guidance.
In a noise impact assessment relating to new development, the existing noise levels will be assessed in conjunction with the predicted noise levels introduced due to the development proposals in order to review the nature and extent of the associated noise impact. Apart from an assessment of the change in noise levels, other factors of the change may need to be considered to determine the extent of any effect and its significance.
A noise impact assessment adhering to good practice principles should be:
- transparent, for instance, the reporting ought to be in a format that is understandable to the layman, the terminology defined, the methodology described, limitations and uncertainties identified and constraints explained;
- focused on the identification of key issues;
- practical by producing information that is sufficient, relevant and reliable for use in decision-making; environmental noise monitoring data and analysis should be achievable within the limits of available data, time, resources and methods considered robust and tested;
- participative by including consultation with a range of stakeholders (although not possible in all cases);
- credible by being objective, impartial, rigorous, balanced, fair and ethical;
- thorough by including an assessment of alternatives, where appropriate, including where appropriate alternative sites, design, technology and mitigation measures; the assessment also ought to include an assessment of a viable worst-case scenario.
The subjective nature of noise in conjunction with the difficulties encountered with linking sound levels with human effects, makes it impossible to set out a prescriptive methodology for noise impact assessments. As such, a degree of professional judgement is required where the assessor must set out the approach taken for a particular project, which has to be bespoke to the constraints and opportunities of the issue at hand.
If you want to discuss anything you have read here please email [email protected]. Keep an eye out for part two and three, coming soon! te
[1] https://www.unep.org/news-and-stories/press-release/deadly-wildfires-noise-pollution-and-disruptive-timing-life-cycles
[2] Environmental permitting guidance: Integrated pollution prevention and control (IPPC) directive