KEM-31 Infrasound (<100KHz) generation and observation in The Netherlands

Low frequency noise (LFN) is a nuisance for those affected, and in extreme cases it can negatively impact health. In the Netherlands, the number of LFN-related complaints is increasing, but the phenomenon has not yet been systematically evaluated and there are no standards in place. LFN is a challenging topic because measurements are sparse, LFN can travel long distances and the research must consider technological, medical, social and contextual factors.

This research aims to define methods described in the literature for assessing the generation of LFN, also known as infrasound, by mining activities, particularly gas production, transport and storage, as well as geothermal energy and salt production activities. Specifically, the research aims to: (1) systematically inventory and characterise LFN generated from induced earthquakes, the flow of gas and liquids through pipeline systems and processing facilities, and the potential impact of LFN on people and assets; (2) systematically inventory methods for using technical observational systems, citizen observations, and models to properly assess current or future infrasound generation and exposure; and (3) provide a qualitative overview of the potential environmental and human impacts of LFN, based on literature and observation possibilities, and reference any safety norms.

FULL RESEARCH QUESTION

The project team investigated the origin and impact of low frequency noises (LFN, sometimes called infrasound) related to mining activities, such as the production, transport and storage of gas, geothermal activities, or salt mining. It also addressed monitoring technologies and future trends of this issue in the Netherlands, providing some recommendations to address it. The results of KEM-31 can be found in the final report 'Methods for the Assessment of Low Frequency Noise (LFN) from mining activities in The Netherlands'.

KEM PROJECT FINAL REPORT

This report first introduces (Chapter 2) in understandable way the concepts of LFN and methods to measure and characterize it. Chapter 3 addresses the report exhaustively the various sources of LFN, and the mechanism how LFN are generated and chapter 4 on human perception of LFN, its health effects and societal response is a well-balanced introduction and analysis of the impact of LFN on people and communities. The extensive final conclusions and recommendations section, only missing a cost benefit-based prioritization, of the report is useful, since it lists in a comprehensive way the key findings and points at future research needs.

The report provides for important recommendations for ‘good practice’ monitoring approaches and instrumentation to be used (and not to be used). These can help to define more standardized and higher quality approaches to establishing LFN impact, and at identifying the potential sources of LFN. More harmonized approaches to measuring LFN, as well as more high-quality measurements overall, are needed to better define the scale of the problem and to identify useful mitigation measures.

The KEM scientific expert panel reviewed the project.

KEM PROJECT EVALUATION

The authors were successful in introducing the relevant topics, making the report a useful and understandable reference document for a wide audience. The report is well structured: It clearly outlines the scope of the research question, the methodology used and results of the study. Overall, the quality of the results and reports is fully satisfactory and in lie with KEM expectation. The report represents in essence a good review article, written for a mixed audience, and it useful rationalize the discussions on LFN, and to suggest future needs. A public summary statement will help to bring this topic to the public.

This report on LFN can serve as a useful and impactful reference document on the state of the art in understanding LFN in the Netherlands. The report is valuable for a range of stakeholder: Municipalities faced with LFN concerns, operators planning future activities or responding to complaints, concerned citizens and media, and last but not least also regulators and the public.  To define the next steps and possible follow up projects, it might be most useful to 1) publish this report and bring it to the attentions of stakeholders throughout Netherlands. 2) Invite interested stakeholders from federal/local offices, academia, industry, public, etc. to a dedicated workshop on LFN and its effects on people that discusses and prioritizes future R&D needs; 3) Translate these needs into project ideas that can be discussed, for example, with SODM/EZK/KEM.

State Supervision of MInes published in 2024 on their website a news message discussing the KEM-31 project outcome.