Cesvaine BIO 350 Wastewater Treatment Plant, Cesvaine, Latvia

Cesvaine BIO 350 is a wastewater treatment plant located in Cesvaine, a town in the Madona Municipality of Latvia. The plant was designed to serve a population of 716, reflecting the scale of a small agglomeration in the Baltic region. As a secondary treatment facility, Cesvaine BIO 350 would have met the requirements of the EU Urban Waste Water Treatment Directive (91/271/EEC), which mandates secondary treatment for agglomerations of this size. The plant had a designed capacity of 1,600 m³/day, though its actual discharge volume was 136.65 m³/day, indicating low capacity utilization before closure. The plant's discharge ultimately flows into the local watershed, contributing to the Daugava River basin, which drains into the Baltic Sea. The Baltic Sea is a sensitive marine environment, and secondary treatment helps reduce nutrient loads that can cause eutrophication in coastal waters.

The plant's treated effluent would have entered the local water system, eventually reaching the Daugava River and then the Baltic Sea. The Baltic Sea is a brackish, semi-enclosed sea with limited water exchange, making it highly sensitive to nutrient pollution. Secondary treatment at Cesvaine BIO 350 would have helped reduce organic matter and nutrient loads, supporting the ecological health of downstream aquatic habitats.