Which of the following is a common method to reduce turbidity in water?

Applying chemical flocculants is a common method to reduce turbidity in water because flocculants work by aggregating small particles and impurities into larger clumps, known as flocs. These flocs can then be more easily removed through sedimentation or filtration processes. This method is particularly effective in treating water that contains suspended solids, typically in various water treatment plants or systems, where achieving a clear and safe water supply is essential.

Using chemical flocculants helps to improve water quality by significantly lowering the concentration of suspended particles, which can include mud, silt, and organic matter that contribute to turbidity. This not only enhances the aesthetic quality of the water but also assists in the removal of pathogens and other contaminants that may be associated with these particles.

The other methods listed do not directly target turbidity reduction in an effective manner and are more related to different aspects of water treatment or water sourcing.