Wertheim starts phosphorus rescue operation: 40 communities pitch in!

Wertheim starts phosphorus rescue operation: 40 communities pitch in!

The sustainable use of sewage sludge is the focus of a newly founded initiative in Würzburg. On July 4, 2025, the Main-Tauber-Aisch sewage sludge utilization association was founded, in which around 40 communities from several districts are involved. The aim is to recover phosphorus from sewage treatment plants, which not only makes ecological sense but is also a legal requirement. From 2029, municipalities will be legally obliged to use phosphorus.

The city of Wertheim, represented by Mayor Markus Herrera Torrez, plays a special role in this municipal association and brings together eleven communities from the Main-Tauber district. Finally something is happening – and on a broad front. The legal basis for this cooperation was signed and approved at the end of April. In this way, the region shows that it has a good knack for environmentally friendly solutions.

Sewage sludge treatment in Würzburg

In order to process the sewage sludge efficiently, a new drying plant is being built in Würzburg. A total of 57,000 tons of dewatered sewage sludge are to be processed there. The treated sewage sludge is then burned in the Scheinfurt community power plant, whereby the valuable phosphorus is recovered from the ash. This is not only a win for the environment, but also a wise use of resources that would otherwise be lost.

The legal regulation for the reorganization of sewage sludge utilization (AbfKlärV), which has been in force since September 27, 2017, shows how important the recovery of phosphorus is. Municipalities with a phosphorus content in sewage sludge of 2% or more are obliged to recover it, with higher levels even having to recover up to 80%. This makes phosphorus a critical resource that is essential not only for fertilizer production but also for life itself.

A climate-friendly resource

According to the Bavarian State Office for the Environment, sewage sludge contains an average of 3.1% phosphorus in dry matter. In Bavaria, around 270,000 tonnes of sewage sludge are produced every year, which corresponds to around 8,600 tonnes of phosphorus per year. This is not only important for agriculture, but also offers potential for sustainable fertilizers. The consolidation of these resources is not just an environmental policy measure, but can also be economically advantageous.

In addition, various pilot projects for phosphorus recovery are underway in Bavaria in order to further refine the technology. Government support for large-scale technical implementations is planned until 2026 in order to advance the projects. The industry is required to become more efficient, and this could also reduce the burden on wastewater fees if the costs of recovery are passed on to the fees.

The dialogue in the industry will continue intensively. A conference of environmental ministers in December 2023 confirmed clear targets and obstacles to implementation need to be analyzed. The Fertilizer Ordinance is also in question, as it needs adjustments to support the promotion of phosphorus recyclates.

The new initiative in Würzburg not only focuses on the recovery of valuable raw materials, but also actively contributes to environmental protection and resource conservation. The coming year 2029 will be a crucial year in which the legal obligation to recover phosphorus must be put into practice. We can't wait to see what the region will do for its sustainable future.

If you would like to find out more about phosphorus recovery and sewage sludge utilization, you can find further information at Press service, Bavarian State Office for the Environment and IWU.