Istanbul is struggling to address marine pollution, with only 34.43% of its wastewater being treated in advanced biological facilities. Despite the urgent need for cleaner waters in the Marmara Sea, the city has made little progress in upgrading its treatment systems, as highlighted in a three-year action plan from the Mucilage Science and Technical Committee. The city’s wastewater treatment infrastructure comprises 90 facilities operated by ISKI, including 13 advanced biological treatment plants, 62 biological treatment plants, seven preliminary treatment facilities, and one membrane wastewater treatment plant. Although these facilities have a total daily treatment capacity of 6.16 million cubic meters, only a fraction of Istanbul’s wastewater receives advanced biological treatment, raising concerns about environmental sustainability and public health.
Following the severe mucilage outbreak in the Marmara Sea in 2021, a strategic action plan was developed to convert all wastewater treatment plants in the region into advanced biological facilities. However, progress has been disappointingly slow; from 2021 to 2024, only 1.4% of the planned upgrades have been completed, far below the ambitious targets set after the environmental crisis. This stagnation poses a significant threat to marine biodiversity and public health, as experts warn that without a swift transition to fully advanced wastewater treatment systems, Istanbul remains at high risk for future mucilage outbreaks and ongoing marine pollution.
