Only a railway embankment prevented worse. The meter-high wall, directly behind the sewage treatment plant in Dümpelfeld, slowed the tide so that the water could only flow onto the site through a gate. Even so, it was about a meter and a half high, as you can still see from the dirt trail on the windows of the company building. "After the flood, the mud was as high as a boot, the entire electrical engineering of the plant was broken," says wastewater foreman and operations manager Patrick Kuhl. The employees could only inspect this later, because initially the plant was cut off - the bridge to the neighboring village of Liers had collapsed and the access road to the sewage treatment plant was torn away.

Although the sewage treatment plant was spared the full force of the water, it was initially inoperable after the flood in mid-July. Garbage and rubbish had collected in the clarifier, in which bacteria otherwise clean the wastewater. That no longer worked, or, as the wastewater master says: "The biology was dead." With the support of the Technical Relief Organization (THW), the armed forces and private companies, the basins were emptied, cleaned and refilled. So that the sewage treatment plant was able to resume operations last Thursday, exactly three weeks after the flood. The driveway is also free again: A makeshift bridge for the Bundeswehr now leads to Liers, and a cleared gravel path leads to the sewage treatment plant.

The plant in Dümpelfeld - a capacity of 11,000 cubic meters, designed for 20,000 population equivalents, which is a measure of the amount of dirt in wastewater - is working again.

The coarse and fine rake pulls leaves and stones out of the water, the sand and grease trap works.

“Biology” is also alive again.

A replacement device supplies the bacteria with oxygen.

The water that flows from the system into the Ahr is almost as clean as before.

That is a partial success.

But that still does not solve the wastewater problem after the flood disaster.

Unfiltered into the Ahr

All four sewage treatment plants in the Ahr valley have been affected by. In addition to the one in Dümpelfeld, the “Untere Ahr” facility is currently being rebuilt in Sinzig. The "Mittlere Ahr" systems in Altenahr and Mayschoss have been completely destroyed, says Thomas Müller from the Structure and Approval Directorate (SGD) North based in Koblenz. "Wherever possible, we work there with mobile wastewater treatment plants."

But not only wastewater treatment plants were destroyed by the flood, but also pipes there.

Collector pipes usually arrive in the plants, which bring together the household wastewater and bring it from the localities to the sewage treatment plants.

"Some of these collectors have been completely destroyed," says the deputy plant manager in Dümpelfeld, Bernd Schmitz.

"Many pipelines have been completely washed away, others were filled with rubble to the top."

Two of these lines lead to the sewage treatment plant in Dümpelfeld, one of which was only slightly damaged, the other very badly.

Now it is a matter of restoring these connection collectors either temporarily or permanently.

How long will that take?

“For a very long time,” says Schmitz.

Maybe years.

"These are sometimes difficult routes that are interrupted."