What is NPDES and how does it regulate point sources?

• A. NPDES oversees the control of nonpoint source pollution with voluntary guidelines.
• B. NPDES requires no monitoring or reporting.
• C. NPDES issues permits with effluent limits for point sources.
• D. NPDES issues permits with effluent limits for point sources and requires monitoring and reporting.

Answer: (D)

NPDES is a permit program under the Clean Water Act that regulates discharges from point sources into U.S. waters. It issues permits that set effluent limits based on technology-based or water-quality-based standards, controlling what can be discharged. The program also requires regular monitoring of discharges and reporting of the results to the regulators, providing data to verify compliance and support enforcement. This combination of binding effluent limits plus mandatory monitoring and reporting is what ensures ongoing protection of water quality. Nonpoint sources aren’t regulated by NPDES, and the monitoring/reporting aspect is essential, not optional.