The cottage textile dyeing industry discharges untreated effluent into water bodies, posing threats to the water quality and the environment in developing countries like Bangladesh. The study aimed to assess the impacts of untreated effluent on surface water in some selected areas of Bangladesh. A total of 96 surface water samples were collected from different locations in three seasons, covering two years from sixteen locations in the Sirajganj district. Most of the parameters exceeded the standards of the DoE-BD, WHO, and FAO. The FTIR analysis showed that the surface water samples contained toxic functional groups, like azo, cyano, etc., indicating a higher level of pollution. The study analyzed various indices, including the contamination factor (Cif) and ecological risk factors (Eir), indicating moderate to ultra-high contamination levels and a higher to serious ecological risk for Cd poisoning of the surface water in the areas. The study observed that the dyeing effluent must be treated before discharging, and a Central Effluent Treatment Plan (CETP) for each cottage industrial area or zone should be installed for building sustainable effluent management, and reducing environmental pollution.