Published on: 12831662. The Department is initiating rulemaking to revise certain procedural language for the existing NPDES Generic Permits for Stormwater Discharge from Large and Small Construction Activities (CGP) and Multi-Sector Generic Permit for Stormwater Discharge Associated with Industrial Activity (MSGP). The purpose of the revisions is to update procedural rule language concerning the stormwater generic permits for consistency with current US Environmental Protection Agency (EPA) requirements.