02-ZII-Environmental technologies Report.docx

The Environmental Technologies report presents a plan to mitigate pollution in the Yahuarcocha Lagoon, located in Ecuador's Imbabura province. The report focuses on Zone Two of the micro-basin, an area with approximately 10,991 inhabitants that currently lacks a sewer system. The lagoon is affected by various contaminants, including domestic and agricultural wastewater, which has led to significant eutrophication. To address this, the proposed solution involves a two-stage wastewater treatment system using nature-based solutions. First, a two-chamber septic tank will serve as a primary treatment to remove solids and prevent clogging. Second, the effluent will be treated using horizontal flow constructed wetlands (HF CWs). This system was chosen because it effectively treats wastewater and provides a nutrient-rich effluent that can be repurposed for agricultural irrigation, the main economic activity in the area. The report details three distinct wetland designs for population clusters of 5, 30, and 115 households, providing specific dimensions and calculations for each. The plan also recommends using local vegetation such as reeds (<i>Phragmites australis</i>) and cattails (<i>Scirpus californicus</i>) in the wetlands, as these plants are native to the region and do not pose an invasive risk. The overall goal is to reduce pollutant loads, support local agriculture, and foster the long-term ecological recovery of the Yahuarcocha ecosystem.