Distinguish technology-based limits from water quality-based limits in NPDES permitting and describe how final permit limits are determined.

• A. Technology-based limits come from ambient water quality standards.
• B. Water quality-based limits reflect ambient water quality standards for the receiving water.
• C. Final permit limits are specified solely by technology-based limits.
• D. The final permit limit is the more stringent of the two.

Answer: (D)