Water Treatment Plant Operator Practice Exam 2026 – Complete Test Prep

The most widely used liquid form of fluoride in water treatment is hydrofluorosilicic acid. This compound is often used to adjust the fluoride levels in drinking water to help prevent dental cavities. Hydrofluorosilicic acid is favored for its effectiveness and ease of use in large-scale water treatment processes.

Fluoridation using this acid is beneficial because it dissolves readily in water and is typically more cost-effective compared to other forms. Additionally, its usage aligns with public health efforts to improve dental health in communities.

The other substances listed, while they do contain fluoride, are generally not utilized in the same capacity for water fluoridation. Sodium fluoride, for instance, is a solid that can be used but is less common in large water systems compared to its liquid counterparts. Calcium fluoride, while it has fluoride as part of its composition, is less soluble in water and thus not as effective for direct fluoridation. Similarly, fluosilicic acid, while effective, is typically not as widely encountered in water treatment systems as hydrofluorosilicic acid.