Herrera de Pisuerga Wastewater Treatment Plant - Castilla y León, Spain

The Herrera de Pisuerga wastewater treatment plant is located in the town of Herrera de Pisuerga, in the province of Palencia, within the autonomous community of Castilla y León, Spain. The plant serves a population of approximately 5,000 residents, providing essential wastewater treatment for this inland community. The plant operates with secondary treatment, which is the standard level required under the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations with a population equivalent between 2,000 and 10,000. Secondary treatment typically involves biological processes to reduce organic matter and suspended solids. The plant has a designed capacity of 5,000 cubic meters per day, matching the population served, and reports a discharge volume of 745 cubic meters per day. The treated effluent is discharged into the local environment, likely into the Pisuerga River or a tributary, which flows through the region. The Pisuerga River is a major tributary of the Duero River, which ultimately drains into the Atlantic Ocean near Porto, Portugal. The plant plays a key role in protecting the water quality of the Pisuerga and Duero river systems, supporting aquatic life and downstream water uses.

The plant discharges into the Pisuerga River basin, which is part of the larger Duero River watershed. The Duero River flows westward through Spain and Portugal, emptying into the Atlantic Ocean. The receiving waters support diverse aquatic ecosystems, including fish species such as barbel and trout. The plant's secondary treatment helps reduce organic pollution and nutrient loads, contributing to the ecological health of the river system and preventing eutrophication in downstream reservoirs and coastal areas.