19 May 2020

Council of State rules onnorms for low-frequency noisecaused by Dutch wind farms

Nicolien van den Biggelaar
Jasper van Uden
How to mitigate unpredictable or uncertain risks has become a pressing topic in these uncertain times. During the decision-making process for activities or developments that may entail uncertain risks, public authorities have to assess the level of precaution that should be taken. The Council of State, the highest administrative court in the Netherlands, recently considered whether this "precautionary principle" demands stricter norms than legally required for the creation of wind parks because of potentially adverse health effects of wind turbine noise (lower frequencies of sound). The Council of State ruled that the politically responsible administrative authority is primarily in charge of assessing the need for such stricter norms. In May 2020, the minister asked the National Institute for Public Health and the Environment (RIVM) to formulate a research agenda on low-frequency noise.

Lower frequencies of sound

There are no legal standards in the Netherlands for lower frequencies of sound (<100 Hz). Official Guidelines explain this as follows: "Although research has been carried out into lower frequencies of sound, in particular into possibilities for assessing this noise, no research has yet been conducted into dose-effect relationships. An official standard is therefore not yet available." (from: Handreiking industrielawaai en vergunningverlening, par. 6.3.1) For planning projects and permits concerning wind farms the competent authorities will therefore follow the rules set out in a decree issued under the Dutch Environmental Management Act. This "Activities Decree" is believed to also cover the impact of lower frequencies of sound. This means that in order to prevent or limit noise pollution, a wind turbine, (or a combination of wind turbines), in order to prevent or limit noise pollution, a wind turbine (or a combination of wind turbines) must not exceed 47 dB Lden and 41 dB Lnight on the façade of sensitive buildings. It is settled case law that this is an acceptable approach. Local residents and other stakeholders have, however, contested this view and have demanded stricter norms to be applied in the environmental and planning permission, as recommended by the World Health Organisation (WHO) in its Noise Guidelines.

Stricter norms for low frequencies of sound?

In a recent judgment the Council of State addressed this question. Stricter norms could follow from direct working norms of international law that can set aside the Activities Decree (Article 94 of the Constitution). In another recent judgment the Council of State answered the question whether such stricter norms could follow from the precautionary principle. International law with direct effect The Council of State ruled that stricter norms that have direct effect in the sense that they can set aside the norms laid down in the Activities Decree do not exist. The stricter norm for wind farms (max 45 Lden) recommended by the WHO in its Noise Guidelines does not qualify as having direct effect. The WHO has qualified the recommendation as "conditional" because the quality of the underlying scientific evidence is rated as "low". The precautionary principle So can the precautionary principle oblige public authorities to apply stricter norms for wind farms? Until recently, the Council of State, only held in specific cases – for example in Windpark Drentse monden en Oostermoer – that the precautionary principle "does not extend to the point where the decision should have been taken not to allow for wind turbines in spatial plans". But in the recent ruling, the Council of State explicitly determined how the precautionary principle should be applied in spatial planning environmental permits for wind farms. The ruling The Council of State determined that there is no legal provision that prescribes the application of the precautionary principle when adopting a spatial plan for wind farms. However, the adverse effect of wind turbines (nuisance for local residents / concerns about public health) should be taken into account. Precaution can therefore be of significance in the considerations to be made by the competent authorities when adopting a spatial plan. In determining the significance of precaution in such a case, the Council of State sought alignment with the European Commission's communication on the precautionary principle. According to the Commission the precautionary principle is particularly important for risk management. It should be seen as part of a structured approach to a three-step risk analysis: risk assessment, risk management and risk reporting. The precautionary principle applies when a preliminary objective scientific evaluation shows that there are valid grounds for fearing potentially dangerous effects on the environment or the health of humans, animals or plants to an extent that could be incompatible with a level of protection chosen for the EU. In situations where there is too little scientific data and where the cause-effect relationships are suspected but not demonstrated, the political decision-makers are faced with the choice between acting or not acting. Because of uncertain risks, it can therefore be decided as a precaution whether or not to take measures. Such measures must be proportionate to the desired level of protection. The European Commission states that assessing an acceptable or unacceptable risk to society is primarily the task of the administrative bodies and decision-makers. This is why the Council of State generally respected the assessment made by the competent authority unless it judges that the competent authority could not reasonably have decided to do so. The Council of State assessed whether the decision: - was based on sufficient knowledge of the relevant facts and interests; - was properly explained; and - did not have a disproportionate impact on stakeholders in relation to the goals to be served by the decision. The Council of State concluded that there is no clear scientific consensus on whether wind turbine noise affects human health. A direct cause-effect relationship between wind turbine noise and health has not been established by science so far. Against this background, the Council of State felt unable to say that the competent authority's position on the health effects of low-frequency noise was not based on sufficient knowledge about the relevant facts and interests or lacked adequate explanation. The Council of State, therefore ruled that it could not substitute its own assessment for that of the competent authority.

Precaution: an administrative, political assessment

The Council of State's answer is clear: the assessment is primarily for the competent authorities to make. In March 2020, questions were asked in parliament concerning the noise pollution and adverse health risks caused by wind farms. One of the questions (Q27) explicitly addresses the precautionary principle as a basis to apply stricter norms in spatial planning to address the potential adverse health effects. In May 2020 the Minister stated in his answer that he has asked the National Institute for Public Health and the Environment (RIVM) to formulate a research agenda on low-frequency noise. This agenda is expected in the summer of 2020 and will be developed into a research program in the Autumn. According to the minister new information from RIVM on low-frequency noise is awaited before making a decision on further policy development in this area.

Lessons learned

Wind turbines' noise and the potential adverse health effects is frequently used as the reason for local communities' objection to the installation of wind farms. Local resistance is a threat for timely reaching the renewable energy goals. Stricter norms The recent judgment of the Council of State makes clear that the precautionary principle actually can lead to additional requirements or stricter norms set by the competent authority in the decision-making phase for wind farms. It can even lead to the refusal to adopt a spatial plan for wind farms. In a parallel judgment the Council of State decided on such a decision by a competent authority to refuse to cooperate. In these types of cases, the competent authority should explain (supported by scientific evidence) why the standards laid down in the Activities Decree are unsound. Specific and local circumstances may give rise to a higher level of protection, according to the Council of State. This can be determined in local, municipal policy. The competent authority must properly explain why the current norms do not provide appropriate protection. Without such specific substantiation, a refusal to adopt necessary spatial planning decisions will not be upheld. Sticking to the current norms At the same time: abiding by the current norms will continue to need explicit explanation taking into account the latest scientific publications, obtaining sufficient knowledge of the relevant facts and interests and balancing the impact on stakeholders in relation to the goals to be served by the decision.

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