COV Dolna Marikova Wastewater Treatment Plant, Považská Bystrica, Slovakia

COV Dolna Marikova is a municipal wastewater treatment plant located in the Horný Milochov area of Považská Bystrica, in the Trenčiansky kraj region of western Slovakia. The plant serves a small population of 510 residents, reflecting its role in a rural or suburban setting within the Váh River basin. The plant provides secondary treatment, which is the standard biological treatment required under the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations with a population equivalent (PE) between 2,000 and 10,000. Although the plant's population served is below 2,000 PE, the secondary treatment level ensures effective removal of organic matter and suspended solids. The designed capacity of 750 m³/day indicates the plant's potential to handle higher loads, while the current discharge volume of 104.37 m³/day suggests ample reserve capacity. The treated effluent is discharged into the local hydrological network, which ultimately drains into the Váh River, a major tributary of the Danube. The Váh River flows southwest through Slovakia before joining the Danube near Komárno, which then empties into the Black Sea. This connection highlights the plant's role in protecting downstream water quality in the Danube basin, a region of significant ecological and economic importance.

The plant discharges into the Váh River catchment, which flows into the Danube River and eventually the Black Sea. The Váh River supports diverse aquatic life and is an important migratory corridor for fish species. The secondary treatment provided helps reduce organic pollution and nutrient loads, contributing to the ecological health of the downstream water bodies.