Questions to legal basis

The applicable principles of water protection legislation are the duty of care, the polluter pays principle and the pollution ban. Annex 3.2 of the Water Protection Ordinance (WPO) also sets out requirements for industrial wastewater and the principle of the state of the art (more on the state of the art in the FAQ “What is the state of the art?”). This means that the production processes and wastewater treatment of industrial and commercial enterprises must comply with the current state of the art.

In addition, every company that discharges industrial wastewater into a body of water or into the public sewer system requires a permit from the competent cantonal authority. This authority periodically checks whether the company is complying with the requirements. The so-called discharge permit often only contains the requirements according to Annex 3.2 WPO. These include heavy metals for example. The competent authority can tighten or ease these requirements. They are tightened, for example, if the central wastewater treatment plant can no longer meet its requirements due to the operational wastewater.

In the case of micropollutants, the competent authority must define specific requirements for each individual case. It derives them, among other things, on the basis of the current state of the art. Because micropollutants relevant to water bodies are often not even known, this process is extremely demanding. For this reason, discharge permits with specific requirements for micropollutants have only been issued in individual cases to date.

The state of the art according to Annex 3.2 No. 1, second paragraph of the WPO means a certain technological level with an advanced state of development that evolves over time. The technical processes must have proven themselves in practical application or must be safely practicable. In addition, the procedures must be economically viable. This is not identical with individual economic reasonableness – i.e. implementation must be assessed on a case-by-case basis. The “state of the art” is thus an undefined legal term and it is constantly evolving. For this reason, the VSA documents the current state of the art within the framework of guidelines and information sheets (see also the information sheet on the state of the art in German or French). This harmonizes enforcement throughout Switzerland and helps to disseminate a uniform state of the art within an industry. Do you have specific questions about the state of the art for industrial and commercial wastewater? You can find more information here.

Other themes

Micropollutants from industry and commerce