Apoyo en la elaboración del documento técnico para la determinación del tiempo T90, como parámetro de diseño para un emisario submarino

Abstract

The increasing urbanization and population growth in coastal areas have challenged the capacity of traditional basic sanitation infrastructure, creating an urgent need for innovative solutions to ensure proper wastewater disposal. In this context, the optimization of the current discharge infrastructure at the Santa Marta Airport is considered. The airport is a significant generator of domestic wastewater resulting from the use of sanitary facilities, infrastructure cleaning, food preparation, and other activities. To improve the existing system, it is essential to consider the requirements established in the most recent renewal of the discharge permit (Resolution 2924 of July 15, 2019), which mandates "improving the structure of the treated domestic wastewater discharge pipe into the Caribbean Sea, ensuring it remains connected and buried along the beach sector, and submerged with ballast in the sea." Currently, the discharge pipeline does not meet optimal conditions and is located on public use land under the jurisdiction of the General Maritime Directorate (DIMAR). Therefore, it is necessary to obtain a maritime concession from the Colombian Maritime Authority to fulfill all the requirements set forth in Article 65 of Decree 2106 of 2019 and the aforementioned resolution. In light of this, the present document develops a technical study aimed at fulfilling one of the requirements for the legalization of a submarine outfall, as stipulated in Article 203 of Resolution 0330 of 2017. This article outlines the preliminary studies needed before designing a submarine outfall, including the determination of T90, which is the main focus of this study. T90 refers to the time required for 90% of coliform bacteria in the receiving water body to be eliminated and must be reported in hours, as specified in Resolution 0330 of 2017. Based on this study, a T90 value was obtained, along with a brief analysis of coliform behavior resulting from the domestic wastewater discharge of the airport. Data were gathered from the airport’s Wastewater Characterization Reports (2015–2023) and compared with technical reports from sampling campaigns conducted between 2015 and 2022 by REDCAM, the Monitoring Network for the Conservation and Protection of Colombia’s Marine and Coastal Waters. Finally, the results indicate that the T90 value was higher during the dry season compared to the rainy season, demonstrating that the quality of coastal waters is affected by anthropogenic activities. This highlights the urgent need to improve inadequate or outdated final disposal systems to prevent coastal and beach pollution, thereby safeguarding public health and marine biodiversity.