What does NSPS stand for and to what does it apply?

• A. National Source Performance Standards; applies to existing sources
• B. New Source Performance Standards; applies to new or significantly modified sources
• C. New Source Pollution Standards; applies to all sources
• D. New Source Performance Standards; applies to new sources only

Answer: (B)

NSPS stands for New Source Performance Standards. These standards apply to sources that are newly constructed or have undergone a significant modification, ensuring that new or substantially changed facilities meet stricter emission or discharge controls than existing ones. That combination—new or significantly modified sources—explains why this choice is correct: it correctly identifies both the acronym and the scope of applicability. The other phrasings don’t fit because they misstate either the meaning of NSPS (not “National” or “Pollution”) or the scope (not all sources, and not limited to just new sources without considering significant modification).