General permit (NPDES and 404) means an NPDES or 404 permit authorizing a category of discharges or activities under the CWA within a geographical area. For NPDES, a general permit means a permit issued under 122.28. For 404, a general permit means a permit issued under 233.37.
40 CFR § 124.2
In addition to the definitions given in 122.2 and 123.2 (NPDES), 501.2 (sludge management), 144.3 and 145.2 (UIC), 233.3 (404), and 270.2 and 271.2 (RCRA), the definitions below apply to this part, except for PSD permits which are governed by the definitions in 124.41. Terms not defined in this section have the meaning given by the appropriate Act.