About how many chemicals are listed as toxic pollutants or priority pollutants under the CWA?

The correct option regarding the number of chemicals designated as toxic pollutants or priority pollutants under the Clean Water Act (CWA) is aligned with the established figure of 126 specific pollutants. This number falls comfortably within the range of 50-200, making the choice accurate.

The CWA recognizes these pollutants due to their potential to harm aquatic life, wildlife, and human health when present in surface waters. The 126 chemicals include various metals, pesticides, and organic compounds. This regulatory framework aims to protect water quality and ensure safe environments for both ecosystems and communities.

Other ranges suggested, such as 500-1000 or higher, significantly exceed the actual number of pollutants under consideration, providing an inaccurate representation of the CWA's priorities for surface water quality management.