In pretreatment contexts, which term best describes pollutants designated as high priority for regulation?

• A. New Indirect dischargers
• B. Appendix A to 40 CFR 423
• C. Priority pollutants
• D. Best management practices

Answer: (C)

In pretreatment contexts, pollutants designated as high priority for regulation are called priority pollutants. This label flags substances that require strict control because they can harm wastewater treatment processes or pass through to the environment. The list of these pollutants is codified in Appendix A to 40 CFR 423, guiding regulators and facilities on which compounds demand focused regulation. The other terms refer to different concepts: new indirect dischargers describe facility status, best management practices are control measures, and Appendix A is the regulatory list itself rather than the designation.