Lomza Wastewater Treatment Plant, Piątnica Poduchowna, Poland

The Lomza wastewater treatment plant is located in Piątnica Poduchowna, a village in the gmina of Piątnica, powiat łomżyński, województwo podlaskie, Poland. The facility serves a population equivalent of 113,688, classifying it as a large agglomeration under EU regulations. Its location near the Narew River places it within the Vistula River basin, which ultimately drains into the Baltic Sea. As a large agglomeration, the plant is expected to provide at least secondary treatment under the EU Urban Waste Water Treatment Directive (91/271/EEC). For sensitive areas, tertiary treatment may be required to reduce nutrient loads. The regulatory framework ensures compliance with discharge standards to protect the receiving water body. The treated effluent likely discharges into the Narew River, a tributary of the Vistula, which flows into the Baltic Sea. This water body supports diverse aquatic life and is part of an important ecological corridor. The plant's operation helps maintain water quality in the region, reducing nutrient pollution and safeguarding downstream ecosystems.

The plant discharges into the Narew River, a major tributary of the Vistula River, which flows into the Baltic Sea. The Narew River valley is ecologically sensitive, supporting diverse aquatic habitats and migratory bird populations. Nutrient reduction from wastewater treatment is critical to prevent eutrophication in the Baltic Sea, a semi-enclosed sea already under pressure from agricultural and urban runoff.