The study looked at how wastewater treatment plant effluents affect the water quality of the Nakdong River in Daegu city. Data from 4 years showed that the river's quality decreased at certain spots, with Habincheon being the most polluted. Industrial plants released more pollutants like COD and TN compared to municipal plants, contributing to the river's pollution. Overall, WWTPs had a small impact on the river's pollution levels, while other sources had a bigger influence.