Danger for Werra and drinking water: Warnings ignored for years

It is a small, inconspicuous salt plant that grows in a meadow in western Thuringia. A plant in the Werratal that is otherwise more likely to be found in the North Sea. The reason: Salty water pushes up from the now brown meadow and forms a puddle – it comes from a company’s disposal.

It is about the disposal of residues from the potash industry in Hesse. For decades, Kali und Salz AG (K+S) had these dumped on heaps, discharged directly into the Werra River as saline waste water, or pressed down into the earth. Around a billion cubic meters of brine have been sunk underground in the last 100 years.

It should actually work like this: The salt water is pressed down through numerous so-called submersible wells into a rock, the so-called plate dolomite. It is porous, partially already filled with slightly salty water. It should serve as a landfill and should not be full by a long shot.

The calculation showed that a large part of the waste water did not fit in at all

But Ute Aragon had already come to a different conclusion in 2007. At that time, she was commissioned by her authority to calculate whether the many millions of cubic meters of brine were actually stored safely in the subterranean rock layer and developed a calculation model for this. Now, for the first time, she is making public what happened back then.

“The balance sheet then revealed that I housed a certain part in the plate dolomite, which was indicated by the measuring point values,” says Ute Aragon, a former employee of the Hessian State Office for Environment and Geology. “And that I have never sunk everything in the plate dolomite due to the dumping quantities that I have sunk so far, but that a certain part must have migrated to another storage facility.”

Ute Aragon calculates that a large part of the submerged brine cannot have been safely deposited in the plate dolomite. Rather, this must have risen into the Buntsandstein, i.e. into the drinking water, or drained underground into the Werra. Nevertheless, the filling continued.

Wastewater: As early as 2007, billions of liters of drinking water and Werra are said to be polluted

To put it less abstractly, Ute Aragon draws an analogy using a cup of milk into which strong coffee is poured. That mixes up and “they displace a mixed water. That’s how I calculated it. It all flows nicely over the edge of the coffee cup, and they can keep sinking and sinking and sinking further.”

If you don’t look to the rim of the cup, nobody wanted to admit that the “coffee cup” was already full. According to Aragon’s calculations, however, more than half of the dumped saline wastewater, i.e. a good 500 million cubic meters, would have been polluting the drinking water or the Werra for a long time – 15 years ago.

In the beginning, Ute Aragon got a lot of approval when she gave her presentation at a meeting of the “Saline Waste Water Coordination Committee”. “Back then, you didn’t see the consequences that come from calculating with halfway realistic numbers.”

Nevertheless, further permits for sinking were issued

MDR did exact research on this: in fact, even the Hessian Ministry of the Environment took up their argument in a lecture in 2008 and explained: “The plate dolomite can no longer be regarded as a secure storage medium.”

The consequence of this should then have been that no further injection permits should be issued by the Kassel regional council. But fewer disposal options mean less potash production. Thousands of jobs would have been threatened.

Then there was a surprising turn for Ute Aragon: “So imagine you are doing a very good job that meets with general approval, that even Kali und Salz AG had checked. And then you were suddenly deducted from your tasks.” , says Ute Aragon. From one day to the next she got new tasks. In 2008, almost a year after her calculations, she suddenly had to hand over all her files. Colleagues turn away, a medical officer is supposed to determine her alleged incapacity. Early retirement follows in 2013.