Wastewater Services

Wastewater treatment at Chemelot.

The wastewater treatment facilities at Chemelot are impressive. With a capacity equivalent to treating the wastewater of approximately 1 million households, our infrastructure leads the way in size and efficiency. The Chemelot site, which extends over 800 hectares, includes 290 kilometers of sewers, several buffer basins, pre-treatment units and the prominent wastewater treatment plant.


Circle Infra Partners operates the Integral Wastewater Treatment Plant at Chemelot, known as the “IAZI. This biological treatment plant treats process water from more than 60 different plants at Chemelot. In addition, the IAZI also treats sewage from the buildings on the site, as well as rainwater and cooling water. Using biomass (bacteria), wastewater is treated in a complex biological process. After treatment, the treated water, also called the effluent, is safely discharged into the Ur River, a river connected to the Meuse River. This process is closely monitored to ensure that the water entering the environment meets all environmental standards and contributes to the protection of our water resources.

Water quality for humans and the environment.

For more than 40 years, we have been committed to clean surface water and good water quality for people and the environment. The IAZI is vital to the Chemelot site. Wastewater may contain a wide range of contaminants, in micrograms per liter or lower concentrations. As operator of the Chemelot umbrella water permit, we bear the responsibility of meeting all permit requirements and operating within the established standards, with great care and every day. We are also closely monitoring the ecological effects on the Natura 2000 area of Grensmaas.

The biological treatment in the IAZI has state-of-the-art removal efficiency and is considered the “best available technology” for process water treatment. The sewer network and the IAZI are continuously monitored with in-line analytical instruments and a bio-monitor to ensure effluent quality and quantity. During incidents, emergencies or extreme weather conditions, process water is stored in temporary basins to prevent potential disruptions to the IAZI’s operations.

Forerunner in water treatment and permitting.

To treat and discharge the treated wastewater to the Ur, Circle Infra Partners manages the Chemelot water permit, one of the strictest and most transparent permits in Europe. For Chemelot, managing the water permit means managing an essential part of the “License to Operate. To this end, we employ permit experts, chemists and chemical technologists in addition to an experienced operations team. These experts specialize in wastewater treatment and know water permit laws and regulations like no other. There are also strategic partnerships and memberships in specialized communities to keep abreast of the latest trends and technologies.

Future-proof water management at Chemelot takes shape.

The transition to renewable energy and green resources cannot be separated from a sustainable approach to industrial water use. Therefore, water transition is also high on the agenda. For example, we are identifying various options for reducing water use and emissions to surface water, taking into account the stricter regulations around water permits and major process changes that will occur at the site as a result of sustainability steps.

Latest news and updates.

Circle Infra Partners – Press Release

Circle Infra Partners – Press Release

Geleen, July 11, 2024 – Circle Wastewater Services B.V. (Circle), as permit holder, is satisfied with the recent ruling of the Limburg District Court in connection with the lawsuit against decisions of the Limburg Water Board. The case was brought because of some unworkable regulations in its permit.

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