FiW revises fee model with pollution surcharge for the city of Freiburg

The assessment of wastewater charges is a sovereign task of the municipalities and is subject to certain requirements and must be updated regularly. After an initial review of the previous assessment methodology from the 1990s, FiW recommended that the city of Freiburg fundamentally revise its municipal fee model and thus adapt it to current legal and technical requirements. The aim here is to achieve transparent and fair fee assessment. As a result, a new calculation formula was developed, which will be used to allocate wastewater fees from next year onwards.

In order to review the existing calculation formula, all relevant documents were examined and checked for compliance with current legal and technical requirements. However, developments in the underlying technical regulations and court rulings on the pollution surcharge in recent years were no longer adequately reflected in the model from the 1990s. For this reason, FiW recommended that the city of Freiburg fundamentally revise its assessment methodology, including a differentiated derivation and documentation of the calculation formula.

To this end, a detailed analysis of the wastewater treatment plant process technology was first carried out in consultation with the wastewater association „Breisgauer Bucht“. The purpose of this was to identify the pollution parameters relevant to the costs incurred on the basis of the specific local conditions and to allocate the costs incurred to the parameters. At the same time, a measurement guideline was developed that formulates the regulations applicable in connection with the pollution surcharge. Among other things, regulations on the type and frequency of sampling, the determination of representative annual values, the handling of special operating conditions, and finally the new calculation formula were established in cooperation with the city of Freiburg. The findings from the cost determination and allocation of the process engineering were then also incorporated into the development of the calculation formula.

In order to enable a forecast of the development of pollution surcharges for the municipality and to ensure fee stability, comparative calculations were then carried out with regard to the previous wastewater fees for the indirect dischargers concerned. Since this inevitably leads to both positive and negative changes in the fee amount, these were justified on technical grounds in order to ensure acceptance by the businesses concerned.

As a result, the city of Freiburg now has a calculation formula for assessing wastewater fees that complies with current case law and all technical regulations and has been enshrined in its statutes. Thanks to the accompanying measurement guidelines and detailed derivation and documentation of the formula development, the municipality now implements an updated, transparent, and polluter-pays wastewater fee assessment.