Cakovec Wastewater Treatment Plant, Grad Čakovec, Croatia

The Cakovec wastewater treatment plant is located in Grad Čakovec, Međimurska županija, Croatia. It serves the municipal area with secondary treatment, a standard level for inland plants under Croatian and EU regulations. The plant's designed capacity of 91,000 m³/day indicates it handles a significant volume of wastewater from the urban population. As a secondary treatment facility, Cakovec employs biological processes to reduce organic matter and suspended solids. Under the EU Urban Waste Water Treatment Directive (91/271/EEC), secondary treatment is required for agglomerations above 2,000 population equivalent discharging into freshwater. The plant's capacity suggests it serves a medium-to-large agglomeration, likely exceeding 150,000 PE, which would mandate tertiary treatment if discharging into sensitive areas. However, the plant's inland location may not require nutrient removal unless the receiving water body is designated as sensitive. The plant discharges treated effluent into local waterways that eventually drain into the Drava River, a major tributary of the Danube. The Danube flows into the Black Sea, making this plant part of a large transboundary river basin. Effective treatment at Cakovec helps protect downstream aquatic ecosystems and water quality in the Drava and Danube rivers.

The Cakovec plant discharges into local streams that feed the Drava River, a major Danube tributary. The Drava-Danube system supports diverse aquatic life and is an important migratory corridor for fish. The Black Sea receives the final outflow, so nutrient removal at inland plants like Cakovec contributes to reducing eutrophication risks in the sea. The region's continental climate and agricultural land use mean that proper wastewater treatment is essential for maintaining river health.