Impact of Domestic Wastewater on Lotic Surface Water Quality: A Literature Review

The contamination of lotic surface waters, defined as freshwater bodies with continuous flow, such as rivers and streams, by domestic wastewater represents an urgent and growing threat to both human and environmental health. The objective was to analyze the scientific literature related to the impact of domestic wastewater on the quality of lotic surface waters, using a comparative approach by geographic region, to identify degradation factors, ecological impacts, and technological strategies applied for their treatment. The analysis focuses on the Americas, the area with the highest number of available studies, and is complemented by evidence from Africa, Europe, and Asia. Common patterns and regional differences are identified in the degradation factors, environmental impacts, and technological strategies used for wastewater treatment. The results demonstrate the priority of integrated approaches that consider technical, community-based and regulatory aspects. These approaches are crucial for addressing the critical factors, including untreated discharges, low sanitation coverage, and contamination by nutrients and pathogens. Documented impacts include eutrophication, biodiversity loss, and associated diseases. The technologies applied vary by region, ranging from conventional systems to natural and advanced solutions. Gaps persist in the integration of these approaches. This study contributes to a stronger global understanding of the impacts of domestic wastewater. It provides a scientific foundation for designing public policies, sanitation strategies, and community-based actions aimed at improving the sustainable quality of water.