Report published by USKOK links Gospić microplastic pollution to nearby waste dump

Polystyrene provides the key link between Gospić’s groundwater pollution and a nearby illegal waste dump, according to a report published by Croatia’s anti-corruption office, USKOK.

The Institute for Water analyzed water samples from three piezometric wells, known as Trag N, Trag O and Trag K. It used chemical fingerprinting to identify the type and quantity of plastic in the groundwater.

Trag N, the upstream point, showed only minimal background contamination. Researchers found negligible traces of polypropylene and no more hazardous polymers. Trag O, the adjacent point, showed low chemical contamination, with most particles identified through detailed spectral analysis as sediment, minerals and clay rather than plastic.

Trag K presented a sharply different picture. The well contained 89.2% of all priority polymers found in the study, with mass concentrations reaching 737,155 micrograms per liter. Polystyrene, used in foam packaging, food containers and disposable plastics, appeared at Trag K but not at the other two locations.

The report says that distribution indicates the pollution emerges after groundwater passes beneath the waste dump rather than arriving from farther away. It also found that microplastic entered the water in pulses. One sample contained larger particles with high mass, while a later sample taken the same day contained 130 smaller polystyrene particles.

The Institute for Water described this pattern as hydraulic washing. Rainwater moving through the dump can carry and break down plastic through porous soil and underground karst channels before transporting it into the aquifer.

The report describes the current condition but is based on only one sampling cycle. The institute said systematic monitoring remains necessary to establish long-term trends and seasonal changes in groundwater pollution.