Evaluation of Wastewater Discharge Reduction Scenarios in the Buenaventura Bay

Abstract

Buenaventura Bay is facing severe pollution due to the direct discharge of untreated wastewater from 695 outlets along the coast, which serves 500,000 people. To address this issue, a study was conducted using the RMA11 water quality model, which was previously calibrated and validated, coupled with the RMA10 3D hydrodynamic model to assess sanitation scenarios in the bay. Five effluent reduction scenarios were proposed and compared based on fecal coliform concentration as an indicator, with evaluation also based on areas where fecal coliform concentrations exceeded the standard for primary contact. The model results revealed poor water quality in the bay, indicating that immediate action was necessary to prevent further deterioration. The proposed staged reduction in discharges would initially have more severe effects than the current situation, but this would improve when the treatment plant became operational. However, even with the plant in operation, the complete sanitation of the bay cannot be achieved, and further measures are required. This study emphasizes the urgent need for effective and sustainable measures to improve water quality in Buenaventura Bay and demonstrates the usefulness of the modeling approach in identifying effective sanitation scenarios to achieve this goal. The results highlight the need for a comprehensive management strategy to tackle pollution in the bay and provide insights for other regions facing similar challenges.

Keywords

• hydrodynamic model
• water quality model
• Colombian Pacific coast
• marine pollution
• fecal coliforms