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Water quality in Lis river, Portugal
Judite Vieira1, André Fonseca, Vítor J P Vilar
1LSRE-Laboratory of Separation and Reaction Engineering - Associate Laboratory LSRE/LCM, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias s/n, 4200-465 Porto, Portugal.
Environmental Monitoring and Assessment
|January 31, 2012
Summary
Untreated wastewater from pig farms has severely degraded Lis river water quality over 30 years. This study assessed pollution sources and water quality, highlighting the urgent need for watershed management to protect this vital water resource.
Area of Science:
- Environmental Science
- Water Resource Management
- Ecology
Background:
- The Lis river basin has experienced persistent ecological issues for three decades.
- Untreated wastewater discharges, primarily from piggery operations, are the main cause of pollution.
Purpose of the Study:
- To assess the impact of domestic, agricultural, and industrial activities on Lis river water quality.
- To develop a watershed management plan for protecting and managing surface water resources.
Main Methods:
- Water quality was monitored at 16 stations along the Lis river and its tributaries.
- Sampling occurred across six periods between 2003 and 2006.
- Analysis included organic matter, nutrients, chlorophyll, and pathogenic bacteria.
Main Results:
- The Lis river generally exhibits poor water quality, failing to meet environmental standards.
- Key indicators of poor quality include low dissolved oxygen, high biochemical oxygen demand, elevated total nitrogen, and excessive fecal coliform counts.
- Pollution is predominantly linked to contamination from pig-breeding farms.
Conclusions:
- Pig farm wastewater is the primary driver of the Lis river's degraded water quality.
- Effective watershed management strategies are crucial for mitigating pollution and restoring the river's ecological health.
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