Stormwater Discharge Improvement and Pollution Prevention Act of 1993

Stormwater Discharge Improvement and Pollution Prevention Act of 1993 - Amends the Federal Water Pollution Control Act to direct the Administrator of the Environmental Protection Agency to issue regulations modifying stormwater discharge permit requirements to: (1) provide that a person issued a permit for discharges composed entirely of stormwater will have satisfied treatment requirements if institutional and nonstructural source controls of pollutants are implemented under an approved pollution prevention plan; (2) exempt a facility from all permitting requirements for discharges composed entirely of stormwater if the facility is insignificant in size, the discharges will have a minimal environmental impact, or mitigation efforts are being implemented to prevent pollutants from entering the discharges; and (3) make existing permits and permit applications for discharges composed entirely of stormwater conform to modified requirements.

Prohibits thhe Administrator or a State from: (1) requiring or enforcing a permit for discharges composed entirely of stormwater before the effective date of regulations under this Act; and (2) issuing or enforcing a permit which requires the treatment of such discharges before October 1, 2000.