What is the main purpose of polishing ponds in wastewater treatment?

The primary purpose of polishing ponds in wastewater treatment is to reduce pathogen levels. These ponds serve as the final treatment stage before the effluent is discharged or reused. The extended retention time in the polishing ponds allows for natural processes, including sunlight exposure and microbial activity, which are effective in inactivating pathogens.

While additional aeration and nutrient removal happen in various stages of wastewater treatment, polishing ponds specifically capitalize on natural biological processes and environmental conditions to minimize health risks by reducing the number of pathogens present in the water. This makes the treated effluent safer for the environment and public health. The role of polishing ponds is crucial, especially in ensuring compliance with discharge regulations and protecting receiving water bodies from contamination.