What is required if an aquatic pesticide is to be used for algae control in a public water supply reservoir?

• A. It must be labeled for such use and applied under the applicable label restrictions; additional approvals may be required.
• B. It can be used if the label doesn't specify.
• C. Algae control is prohibited in all reservoirs.
• D. Only household products can be used.

Answer: (A)

Using aquatic pesticides is governed by the label and regulatory approvals. For algae control in a public water supply reservoir, you may only use a product that is specifically labeled for that use in such water bodies, and you must follow every restriction listed on the label—including application rate, timing, method, and any water-use or intake proximity rules. Because a reservoir supplies drinking water, there are often additional approvals or notices required from regulators and the water supplier before application. If a product isn’t labeled for use in a public drinking-water reservoir, it cannot be used. This is why the best answer emphasizes both labeling for the exact use and any extra approvals that may be needed.