COV Vranov Lomnica Wastewater Treatment Plant, Vranov nad Topľou, Slovakia

COV Vranov Lomnica is a municipal wastewater treatment plant located in the Čemerné area of Vranov nad Topľou, in the Prešovský kraj region of eastern Slovakia. The facility serves a population of approximately 18,422, classifying it as a medium-sized agglomeration under EU regulations. As a plant in an EU member state, COV Vranov Lomnica is subject to the Urban Waste Water Treatment Directive 91/271/EEC, which requires secondary treatment for agglomerations between 10,000 and 150,000 population equivalent. The directive also mandates more stringent treatment if the receiving waters are designated as sensitive areas. The plant discharges treated wastewater into the local watershed, which ultimately drains into the Topľa River, a tributary of the Ondava River, part of the Bodrog River basin that flows into the Tisza River and eventually the Danube River and Black Sea. The facility plays a key role in protecting water quality in this region, supporting aquatic life and downstream ecosystems.

The treated effluent from COV Vranov Lomnica enters the Topľa River, which flows into the Ondava River, a major watercourse in eastern Slovakia. The Ondava joins the Latorica to form the Bodrog River, which crosses into Hungary and feeds the Tisza River, a tributary of the Danube. This river system supports diverse aquatic habitats and is important for migratory fish species. The plant's operation helps maintain water quality standards in this transboundary basin, reducing nutrient loads that could otherwise contribute to eutrophication in downstream lakes and the Black Sea.