Liepas ciema NAI Wastewater Treatment Plant, Liepas pagasts, Latvia

Liepas ciema NAI is a wastewater treatment plant located in Liepas pagasts, Cēsu novads, Latvia, within the boundaries of Gauja National Park. The plant serves a population of approximately 4,052, placing it in the small-to-medium agglomeration category under EU classification. The plant employs advanced treatment technology, which goes beyond the secondary treatment standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for sensitive areas. With a designed capacity of 2,000 m³/day and a discharge volume of 444.85 m³/day, the facility operates well within its capacity, ensuring effective treatment of municipal wastewater. The treated effluent is discharged into the Gauja River basin, which flows through Gauja National Park and eventually into the Baltic Sea. The advanced treatment level helps protect the park's sensitive aquatic ecosystems and supports the ecological health of the Gauja River, a key waterway in northern Latvia.

The plant discharges into the Gauja River basin, which flows through Gauja National Park and eventually reaches the Baltic Sea. The Gauja River supports diverse aquatic life and is an important migratory corridor for fish species. The advanced treatment level helps minimize nutrient loading and protects the sensitive downstream environment, including the park's wetlands and forests.