What does the fish inside a circle mean after EPNSA1?

The fish symbol inside a circle after EPNSA1 likely represents a specific designation or classification related to the Environmental Protection Agency's National Pollutant Discharge Elimination System (NPDES) permit program. It may indicate a focus on aquatic life or water quality protections. However, without additional context, the exact meaning can vary, so it's essential to refer to specific guidelines or documents related to the EPNSA1 designation for precise interpretation.