Copper sulfate is used in surface water reservoirs primarily for controlling what?

Copper sulfate is primarily used in surface water reservoirs to control algae. It acts as an algaecide, effectively reducing the growth of algal blooms that can lead to problems such as reduced water quality, taste and odor issues, and depletion of oxygen in the water body. By applying copper sulfate, water treatment facilities can manage and mitigate these excessive algal growths, which is crucial for maintaining safe and clean drinking water and aquatic ecosystems.

The other options are not the main focus of copper sulfate usage. While sediment deposition is a concern in reservoirs, copper sulfate does not target sediments directly. Coliform bacteria are typically controlled through different disinfection methods rather than algaecides like copper sulfate. Inorganic sediments are also managed through filtration and other physical processes rather than chemical treatment with copper sulfate. Thus, copper sulfate's primary effect is best suited for the control of algae in water bodies.