City council strives for comparable water quality throughout Offenbach

Since August 2025, the water supplier ZWO has been receiving additional drinking water from Hessenwasser to ensure the supply of drinking water to the Offenbach city area. This water, which is fed into the Offenbach pipeline network at Kaiserlei, is already slightly chlorinated on Frankfurt city territory as a precautionary measure in coordination with the Frankfurt City Health Department. It fully complies with the legal requirements of the German drinking water supply and is hygienically flawless. However, this chlorination is still noticeable on some days, particularly in the harbor district. The city is therefore endeavoring to find solutions to eliminate the smell of chlorine as completely as possible.

In the meantime, Hessenwasser has changed the admixture of the water that is supplied to Offenbach via Frankfurt. As a result, the chlorine can only be smelled in the port on some days. "This has certainly led to improvements, but the quality cannot be reliably guaranteed for every day. I have been to the port myself a few times to taste the water and am in regular contact with some of the residents. Of course, the health department also continues to check the water quality. We need a permanent solution," explains Mayor Groß. "That's why we see a need for further action on the part of the city." This is also confirmed by Lord Mayor Dr. Felix Schwenke, who makes it clear that the full-time municipal council is united in its efforts to find a permanent solution: "We don't just want formally and hygienically flawless water that complies with the Drinking Water Ordinance. We also want the water quality to be largely the same everywhere in Offenbach in the future. Because in the coming years, we will need even more supplied water in the middle of the growing Rhine-Main region, just like Frankfurt or Hanau, for example."

In recent weeks, the ZWO has already examined technical solutions at the request of Offenbach's municipal authorities, in particular the installation of a central activated carbon filter at Kaiserlei, venting of the port pipeline and the extension of the port pipeline to form a ring pipeline. Due to the location of the harbor island, the harbor pipeline is currently a "dead-end pipeline" - the chlorinated water there cannot mix with the chlorine-free ZWO water in the pipeline network as it can in the rest of the city.

However, all tests to date still leave open the question of what is effective and feasible. With regard to a central activated carbon filter at Kaiserlei, for example, it needs to be examined in greater detail at which location this can be built at all. Mayor Groß adds: "We want to find out what is really effective and where, and in the end we also need an affordable solution. The city is now preparing to commission external experts in order to reliably clarify the open questions together with the ZWO and, if necessary, find further solutions. Although this will take some time, we will then have a sound basis on which to make a responsible decision, also with regard to costs."