Which option correctly expands the acronym NPDES?

• A. National Pollutant Discharge Elimination Standard
• B. National Pollutant Discharge Elimination System
• C. National Pollutant Discharge Emission System
• D. National Pollution Discharge Enforcement System

Answer: (B)

This question tests knowledge of the regulatory acronym and what that program actually does. NPDES stands for National Pollutant Discharge Elimination System, which is the permit-based program under the Clean Water Act that controls discharges of pollutants from point sources into U.S. waters. The word System emphasizes the regulatory framework of permits, monitoring, and compliance designed to eliminate or greatly reduce harmful discharges.

Why the correct phrase fits: it uses Pollutant (singular) to describe the harmful substances, Discharge to describe the act of releasing those substances, Elimination to reflect the goal of removing discharges, and System to denote the regulatory program that administers permitting and enforcement. The other options use different words that don’t match the official program name: Standard would suggest a fixed limit rather than a permit system; Emission and Enforcement modify the meaning away from the established program title; Pollution instead of Pollutant also changes the term.