BUT saved more than 360,000 PET bottles last year

Lokni is a Czech network of filtration stations that allow users to fill their own bottles with high-quality drinking water — both sparkling and still. The water passes through carbon filters and is treated with UV-C technology: chlorine, microplastics, pharmaceutical residues, and unwanted bacteria are removed while the water retains its natural mineral composition. The stations were originally launched under the brand Filtermac, which was later renamed Lokni. At participating BUT faculties, the water is free to refill. The stations are operated via the Lokni mobile app, available for Android and iOS — registration is possible with any email address; a university email is not required. In the Lokni network, the stations at BUT are listed as Lokni+, which means every user automatically receives the FREE tariff. With it, users can refill up to 3 liters of sparkling or still water per day free of charge. An instructional video shows how the refilling works in practice.

Faculties at BUT joined the Lokni network as part of an effort to reduce single-use plastics and offer students and staff easier access to drinking water directly in university buildings. And the numbers show that it works. According to Lokni’s 2025 annual report, BUT saved more than 360,000 PET bottles in the past year alone. Since the beginning of the partnership, the total has reached nearly 1.75 million bottles.

Currently, four BUT faculties are involved in the project: the Faculty of Civil Engineering (FCE), the Faculty of Electrical Engineering and Communication (FEEC), the Faculty of Business and Management (FBM), and the Faculty of Information Technology (FIT). The largest user is the Faculty of Civil Engineering with more than 5,600 students, followed by FEEC (3,200), the Faculty of Business and Management (2,630), and the Faculty of Information Technology (2,300). Together, BUT students and staff are saving not only plastic but also CO₂ emissions that would otherwise be produced during the manufacturing and transportation of bottled water.

FEEC also contributes significantly to the university-wide results. In 2025 alone, the use of the stations there saved more than 115,000 PET bottles, 2,885 kg of plastic, and 6,635 kg of CO₂. An interesting metric is the per-student calculation — FEEC reaches the highest value among all participating faculties, about 36 half-liter bottles per student per year. In other words, each student at the faculty “saves” roughly one full shopping basket of plastic annually that never has to be produced.

The principle is simple. All you need is your own bottle and the mobile app — and every time you refill your water, there is one less PET bottle. And it is precisely these small everyday actions that quickly add up across the university.

Related article: Lokni at FEKT: more than 115,000 PET bottles saved per year.