How Czech Engineers Beat Europe’s Toughest Water Test

Blansko’s ozone–carbon system wipes out pharma waste as EU enforces stricter clean-water rules

6 Jun 2025

A quiet shift is underway in the Czech Republic, and it could change how Europe cleans its water. In the town of Blansko, a pilot system that pairs ozone with granular activated carbon has removed more than 90 percent of pharmaceutical residues from treated wastewater. The timing is striking, as the European Union begins enforcing its toughest water standards yet.

The technology is not flashy. It works by adding an ozone treatment step, followed by filtration through activated carbon that traps stubborn chemical traces. Installed at Blansko’s existing treatment plant, the system ran under real world conditions with modest energy use and no major service interruptions.

That practicality matters. Conventional plants were never designed to filter out traces of antidepressants, painkillers, or cosmetic chemicals. Upgrading what already exists is far cheaper and faster than building from scratch.

“This shows we don’t need to rebuild everything. We can upgrade and comply,” said a senior engineer involved in the trial.
The pressure to act is growing. As of March, the EU’s revised Urban Wastewater Treatment Directive requires large plants to introduce advanced treatment to tackle micropollutants. For the first time, pharmaceutical and cosmetic companies will help cover the cost, easing the burden on public utilities and ratepayers.

Blansko’s results offer a roadmap. Municipalities in Flanders and the Netherlands are preparing similar ozone and carbon trials, while others across Europe are studying the Czech data as they weigh their own upgrades. The appeal is clear: a retrofit friendly system that delivers measurable results.

Still, questions linger. Europe will need a steady supply of activated carbon, and operators will be watching long term costs closely. Scaling up from one town to an entire continent is never simple.

Even so, optimism is building among water experts. One regional consultant called the pilot a turning point, proof that meaningful environmental progress does not have to take decades or require billion euro budgets.
As Europe tightens its grip on pollution, Blansko’s experiment suggests that cleaner rivers and safer water may be closer than many thought.