Germany – Feasibility study, advisory service, analysis – Zusammenschluss von Kläranlagen an der Wied und Errichtung einer vierten Reinigungsstufe

On 17.03.2025, the Ministry for Climate Protection, Environment, Energy and Mobility Rhineland-Palatinate (MKUEM) informed that a list of 65 wastewater treatment plants has been compiled at the state level, for which the establishment of a fourth treatment stage is considered sensible according to the federal orientation framework. This list includes both the two "large" wastewater treatment plants of the Altenkirchen-Flammersfeld municipal utilities – the Altenkirchen-Leuzbach wastewater treatment plant and the Peterslahr wastewater treatment plant – as well as the planned new construction of the Mudenbach wastewater treatment plant of the Hachenburg municipal utilities. The existing wastewater treatment plants Mudenbach, Hachenburg and Steinebach a.d.W. are to be combined in the Mudenbach wastewater treatment plant, including the wastewater from the Westerwald Brauerei Hachenburg. This project already has studies available. These will be referred to subsequently as Mudenbach(neu). Investigations into the 4th treatment stage were also already considered and are available as part of the study. On 16.02.2026, the Structure and Approval Directorate North, Regional Office Montabaur (SGD North), as the Higher Water Authority, informed that a merger of the Mudenbach (neu), Altenkirchen-Leuzbach and Peterslahr wastewater treatment plants is expected to yield considerable economic and water management synergies, particularly with regard to the establishment of a fourth treatment stage. The SGD North therefore recommends examining a merger of the wastewater treatment plants and commissioning a corresponding study. The Altenkirchen-Flammersfeld municipal utilities and the Hachenburg municipal utilities intend to award this study. The aim of this request is to negotiate the framework conditions for the scope of services and the costs of the study.

1. Objective of the investigation

The central question of the study is: Is it economically and water management-wise sensible to merge the Mudenbach (neu), Altenkirchen-Leuzbach and Peterslahr wastewater treatment plants?

2. Variants to be investigated

Under the premise that a fourth treatment stage is planned for all three wastewater treatment plants, the following variants are to be investigated:

1. Connection of the Mudenbach (neu) and Altenkirchen-Leuzbach wastewater treatment plants to the Peterslahr wastewater treatment plant

2. Connection of the Mudenbach (neu) wastewater treatment plant to the Altenkirchen-Leuzbach wastewater treatment plant; the Peterslahr wastewater treatment plant remains independent

3. Connection of the Altenkirchen-Leuzbach wastewater treatment plant to the Peterslahr wastewater treatment plant; the Mudenbach (neu) wastewater treatment plant remains independent

4. Continued operation of all three wastewater treatment plants as independent plants

The variants are to be investigated both in terms of water management impacts – particularly on the receiving water Wied – and in terms of economic impacts. For the economically preferred variant (excluding variant 4), it is to be additionally examined whether a merger is also sensible without the establishment of a fourth treatment stage.